Management of Keratoconus
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1) Phakic IOLs are artificial lenses implanted in the eye to correct refractive errors while leaving the natural lens intact. They are classified as angle-supported, iris-fixated, or posterior chamber IOLs.
2) The first phakic IOLs date back to the 1950s but modern designs from the 1980s/90s include the Artisan iris-claw lens and posterior chamber lenses like the ICL.
3) Ideal phakic IOL candidates have a stable refraction and meet endothelial cell and anterior chamber depth requirements. Assessments include VA, biometry, and endothelial cell counts.
This document discusses sources and management of postoperative astigmatism after cataract surgery. It notes that the main sources of astigmatism are preexisting astigmatism, incision characteristics like length and location, and suture characteristics like type, tension, and placement. Larger or superior incisions, and sutures that degrade quickly or are placed unevenly, tend to cause more astigmatism. Managing factors like smaller incisions, frown-shape cuts, posterior placement, uniform tension, and non-degrading suture material can help minimize postoperative astigmatism. Precise suture removal timing and selective cutting can further refine astigmatism outcomes after surgery.
Boris Malyugin, M.D., PhD.'s presentation about Malyugin Ring® pearls. The key learning points of the presentation include the step-wise approach in managing small pupils, the main drivers for the decision to use pupil expander device, and the Malyugin Ring® implantation and removal pearls.
This document discusses various vitreous substitutes and intraocular gases used to replace the vitreous humor after surgery. It describes the anatomy and composition of the natural vitreous and ideal properties for substitutes. Common substitutes discussed include gases like air, sulfur hexafluoride and perfluorocarbons; liquids like silicone oil, perfluorocarbon liquids and semi-fluorinated alkanes; and experimental polymers and implants. The document compares different options and provides details on how each works, associated complications, and appropriate uses.
This document discusses surgical induced astigmatism following cataract surgery. It notes that astigmatism has a significant impact on vision and is influenced by surgical technique and incision size and type. Various factors can induce astigmatism including incision location and size, suture type and placement, and wound compression or gape. Evaluating astigmatism involves tools like retinoscopy, keratometry and corneal topography. Managing astigmatism may involve selective suture removal to reduce cylindrical error over time.
Iol power calculation in pediatric patientsAnisha Rathod
- Many factors affect intraocular lens (IOL) power calculation in pediatric patients including age at surgery, laterality, amblyopia, axial length, keratometry, and expected myopic shift due to ongoing eye growth.
- Normal eye development involves rapid growth of the axial length and changes in lens power in the first years of life.
- Target postoperative refraction must account for this myopic shift and generally involves undercorrecting more in younger patients.
- Accurate biometry using immersion ultrasound or optical techniques is important to minimize errors from corneal compression.
- Formulas, IOL type and position can further influence outcomes.
Gonioscopy: gonioscopic lenses, principle and clinical aspectsDr Samarth Mishra
This document discusses gonioscopy, which is used to examine the anterior chamber angle. It begins by explaining that the angle cannot be viewed directly due to total internal reflection at the cornea. Gonioscopic lenses eliminate this effect by matching the cornea's refractive index. There are two main types of lenses - indirect lenses use mirrors and direct lenses refract light. The document then describes various gonioscopic lenses and techniques like indentation gonioscopy. It outlines the clinical uses of gonioscopy and provides examples of gonioscopic findings. In summary, the document provides an in-depth overview of gonioscopy equipment, techniques, and applications.
This document outlines several new treatments and technologies for dry eye disease. It discusses increased expenditures on dry eye medications from 2001-2006 driven by Restasis. Six new tools to treat dry eyes are described, including anterior segment OCT, osmolarity testing, LipiFlow, Inflammadry, Ziena eyewear, and intraductal meibomian gland probes. New artificial tear formulations and the use of diquafosol and cyclosporine for dry eyes are also covered.
This document discusses techniques for managing a small pupil during cataract surgery. Small pupils are defined as less than 4mm in diameter and can increase risks of complications during surgery. Medications like Flomax and glaucoma medications can cause miosis preoperatively. Intracameral lidocaine and epinephrine or Omidria can help maintain pupil size during surgery. For small, floppy pupils, iris hooks, retractors, or expansion rings can be used. For small, stiff pupils, mechanical stretching techniques may work better. Proper pupil management techniques can help reduce surgical risks in patients with small pupils.
This document discusses the use of bandage contact lenses after refractive surgery procedures like LASIK and PRK. It describes how bandage contact lenses can help reduce pain, promote healing of the epithelium, and prevent complications like striae or epithelial in-growth after surgery. Different types of bandage contact lens materials are reviewed, including hydrogels, silicone hydrogels, collagen shields, and scleral lenses. Factors like oxygen transmissibility, diameter, and disposable versus reusable lenses are discussed when selecting a bandage contact lens. Potential complications are also mentioned.
MIGS procedures are newer glaucoma surgeries that offer more modest intraocular pressure (IOP) lowering than traditional surgeries, but with a safer risk profile. They are targeted at patients with mild to moderate glaucoma and involve minimally traumatic, ab-interno approaches that preserve the conjunctiva. Common MIGS procedures include implants that bypass the trabecular meshwork (iStent, Hydrus), drain into the suprachoroidal space (CyPass), or excise the trabecular meshwork (Trabectome). Studies show that MIGS procedures lower IOP by 15-20% on average when combined with cataract surgery. Complications are generally mild and
This document provides information on penetrating keratoplasty (PKP), which involves replacing the full thickness of diseased corneal tissue with donor corneal tissue. It discusses the types of PKP including optical, therapeutic, and tectonic. The common indications for PKP include corneal scarring, infections, dystrophies, and thinning. Preoperative evaluation and obtaining a suitable donor corneal tissue is important. The surgical procedure involves trephination of the donor and host corneas followed by suturing the donor graft. Postoperative complications can include rejection, infections, glaucoma and astigmatism. Long term graft survival depends on the preoperative diagnosis and condition.
Soft Contact Lenses: Material, Fitting, and EvaluationZahra Heidari
Soft contact lenses are made from various materials like silicone and hydrogels, with advantages like comfort and easier fitting but disadvantages like potential for complications. The document discusses the history and evolution of contact lens materials, characteristics of different lens types, factors to consider for patient fitting like base curve and power selection, and how to evaluate fit and make modifications if needed. Proper patient selection and evaluation is important for successful fitting of soft contact lenses.
The document provides an introduction to refractive surgery, describing different types of refractive errors and methods used to correct them. It discusses procedures like LASIK, PRK, and lens implants. LASIK involves creating a corneal flap then sculpting the cornea with an excimer laser. PRK removes the outer corneal layer then applies the laser. Lens implants are for higher refractive errors or when other methods don't work. The risks, recovery times, and potential outcomes are outlined for each procedure.
Post-operative endophthalmitis (POE) is an inflammatory response in the eye following surgery that can lead to vision loss. It is most commonly caused by bacteria entering through surgical wounds. POE presents with pain, redness, decreased vision and occurs usually 1-7 days after surgery. Treatment involves intravenous and intravitreal antibiotics based on culture and vitrectomy in severe cases. Proper pre-operative cleaning and use of prophylactic antibiotics can help prevent POE. A case of retained intraocular foreign body following a work injury is also discussed, demonstrating the importance of safety equipment and need for thorough examination and removal of any objects in such cases.
The document describes the use of various Pentacam maps and indices for screening patients for keratoconus, including:
1) The standard 4-map composite report, keratoconus map, Holladay report, and Belin/Ambrosio Enhanced Ectasia Display.
2) Key features to examine on each map include anterior and posterior elevation maps, pachymetry maps, curvature maps, and indices values.
3) The Belin/Ambrosio Enhanced Ectasia Display aims to improve sensitivity by calculating an "enhanced" best fit sphere reference surface that excludes the thinnest corneal region, highlighting differences between normal and ectatic corneas.
This document compares and contrasts AS-OCT (anterior segment optical coherence tomography) and ultrasound biomicroscopy (UBM) imaging techniques for evaluating the anterior eye segment.
It discusses that AS-OCT provides non-contact, high resolution cross-sectional imaging of the anterior segment structures without touching the eye. UBM uses high frequency ultrasound to generate detailed 2D images of the anterior segment, allowing visualization of structures like the iris and angle.
While both techniques allow qualitative and quantitative assessment of the anterior chamber angle and structures, AS-OCT has advantages of being non-contact, faster imaging, and less operator dependency compared to UBM. However, UBM can image deeper into the posterior iris and has greater penetration than
Choroidal neovascular membranes (CNVM)Md Riyaj Ali
Choroidal neovascularization (CNV) involves the abnormal growth of new blood vessels from the choroid layer of the eye through Bruch's membrane. This can cause vision loss and is a common cause of wet macular degeneration. CNV occurs due to alterations in Bruch's membrane and high levels of vascular endothelial growth factor. It is classified based on its location relative to the retinal pigment epithelium and fovea. Symptoms include sudden vision loss and visual distortions. CNV is diagnosed through imaging like optical coherence tomography and fluorescein angiography and treated with injections of anti-VEGF drugs to inhibit blood vessel growth.
The Scheimpflug principle allows for imaging of the anterior eye segment with maximal depth of focus. Scheimpflug systems like the Pentacam and Orbscan use this principle to provide detailed tomography and topography maps of the cornea and anterior chamber. The Pentacam uses a rotating Scheimpflug camera combined with a static camera to construct a 3D model from 25,000 data points. It analyzes parameters like corneal thickness, curvature, astigmatism, and anterior chamber dimensions. The Orbscan uses slit scanning to create elevation maps of the anterior and posterior corneal surfaces and measure pachymetry. Both devices help evaluate conditions like keratoconus and guide refractive surgery planning.
Corneal ectasias are a group of diseases characterized by corneal thinning and changes in shape. The main types are keratoconus, keratoglobus, and pellucid marginal degeneration. Keratoconus causes a cone-shaped protrusion of the cornea typically in the inferior region. It has a variety of signs on exam including Fleischer rings, Vogt's striae, and corneal scarring. Treatment involves contact lenses, intracorneal ring segments, corneal cross-linking, or transplantation. Keratoglobus is a non-progressive ectasia causing generalized thinning. Pellucid marginal degeneration causes a band of thinning separated from the limbus.
This presentation describes all the clinical aspects of keratoconus management
You can watch the illustrated presentation in this link :
https://www.youtube.com/watch?v=pYxwZPGm7e4&list=PLZ_mM13I_TrhWavjTmE9NjW1O5bGxkONO&index=13
Keratoconus is a non-inflammatory thinning and protrusion of the cornea that results in impaired vision. It typically begins at puberty and progresses slowly over 10-20 years before stabilizing. Diagnosis involves examining for signs like Munson's sign, Fleischer's ring, and irregular astigmatism using tools like retinoscopy, keratometry, and corneal topography. Treatment begins with glasses or contact lenses and may progress to corneal grafting for advanced cases.
This document provides information about keratoconus, a non-inflammatory thinning of the cornea that causes a cone-shaped bulge. It is most common in teenagers and young adults. The document discusses the definition, stages, etiology, associations, clinical features, investigations, and management of keratoconus. Keratoconus is typically managed initially with glasses or contact lenses, and more advanced cases may require collagen cross-linking, intracorneal ring segments, deep anterior lamellar keratoplasty, or penetrating keratoplasty to correct vision and stop further thinning. Differential diagnoses include keratoglobus and pellucid marginal degeneration.
This document discusses eyelid ectropion, including its definition, classification, causes, clinical presentation, evaluation, and surgical treatment options. Eyelid ectropion refers to eversion of the eyelid away from the eye. It is classified as involutional, cicatricial, paralytic, or mechanical. Surgical treatment depends on the type and severity of ectropion, and may include procedures like conjunctival cautery, wedge resections, horizontal lid tightening, and sling or grafting techniques. Potential complications of ectropion surgery include under or overcorrection, recurrence, and eyelid notching or punctal injury. A thorough evaluation is important to plan the appropriate surgical approach for correcting the
Contact lens options in keratoconus hiraHira Dahal
Rigid gas permeable lenses are commonly used to correct vision in keratoconus, though some patients cannot tolerate them. Piggyback or hybrid lens systems can improve comfort by combining a rigid lens with a soft lens. Newer options like mini-scleral lenses and Rose K lenses are designed specifically for keratoconus, vaulting the irregular cornea to improve vision. The Boston PROSE treatment also creates a new smooth optical surface over the cornea using customized prosthetic lenses. While fitting lenses for keratoconus can be challenging, contact lenses are often able to restore vision without surgery.
Keratoconus is a degenerative condition where the central cornea progressively thins and steepens, causing irregular astigmatism and vision changes. While the exact cause is unknown, risk factors include eye rubbing and genetic factors. Diagnosis is based on signs of corneal thinning, steepening, and irregularity seen on examination. Mild cases are managed with glasses or contact lenses, while more severe cases may require corneal collagen crosslinking or surgery.
ECTROPION^JENTROPION AND THEIR MANAGEMENT 2.pptxHarshika Malik
This document discusses ectropion and entropion of the eyelids, including their causes, types, clinical evaluation, and management. Ectropion is the outward turning of the eyelid margin, while entropion is the inward turning. Involutional ectropion most commonly affects the lower eyelids in elderly patients due to gravitational changes. Management depends on the type but may include procedures to shorten the eyelid or correct underlying issues like laxity of the medial or lateral canthal tendons. Prompt treatment is important to prevent complications such as dry eye or corneal damage.
The document discusses keratoconus, a non-inflammatory thinning of the cornea. It is mostly bilateral and affects girls aged 15-20, causing visual impairment due to irregular astigmatism. Keratoconus is classified into four stages based on criteria like corneal curvature and thickness. Various theories for its causes are discussed, including enzymes, genetics, eye rubbing. Clinical features include corneal protrusion, thinning, Fleischer's ring, and scarring in advanced cases. Diagnosis involves tools like keratometry, topography and pachymetry to assess curvature, thickness and irregularity. Treatment options include glasses, contact lenses fitted using different techniques, and surgeries like collagen crosslinking and keratoplasty for
Keratoconus is a non-inflammatory condition where the cornea thins and changes from a dome shape to a cone shape. The exact cause is unknown but factors like heredity, eye rubbing, hormones, and UV light may contribute to molecular changes in the cornea. Symptoms include progressive nearsightedness, blurred vision, glare, and sensitivity to light. Signs include corneal thinning, Fleischer's ring, and Vogt's striae visible on examination. Treatment depends on severity but may include glasses, rigid gas permeable contact lenses, corneal collagen cross-linking, intracorneal ring segments, or keratoplasty for later stages.
This document discusses keratoconus, a degenerative condition characterized by thinning and steepening of the central cornea. It classifies keratoconus by severity from mild to severe based on diopter measurement. Symptoms include defective vision, photophobia, ghost images, and halos around lights. Diagnosis involves examination findings like scissor reflex on retinoscopy, irregular circles on Placido disc, and thinning/bulging of the central cornea on corneal topography. Management includes spectacle correction for mild cases, rigid contact lenses fitted with light central touch, and intracorneal ring segments or collagen cross-linking to halt progression. Surgery like lamellar or penetrating keratoplasty is indicated for
Fenestrations are small holes drilled into rigid gas permeable contact lenses that were originally used to improve oxygen permeability but are now mainly used for large scleral lenses to reduce suction. Corneal topography maps the surface curvature of the cornea which is important for contact lens fitting and monitoring conditions like keratoconus. Lysozyme is the main tear film protein that fights microbes but can denature and build up as deposits on contact lenses. Mucin balls are lipid and protein deposits that form on contact lenses but do not affect vision or comfort. Corneal thinning can result from long-term extended wear soft contact lens use due to hypoxia.
This document discusses keratoconus, a progressive eye disorder causing corneal thinning and irregular astigmatism. Key signs include an irregular red reflex seen with an ophthalmoscope, Vogt striae seen on slit lamp exam, and a protruding cone shape of the cornea. Diagnosis involves examining the cornea and using tools like keratometry and OCT. Treatment focuses on rigid contact lenses to correct vision and corneal collagen cross-linking to slow progression. Surgical options like intrastromal corneal ring segments or keratoplasty may be considered for more advanced cases.
Keratoprosthesis is a surgical procedure that replaces a severely damaged or diseased cornea with an artificial cornea to restore vision. The first attempts at keratoprosthesis in humans date back to the mid-19th century, but most implants failed. Modern keratoprosthesis designs like the Boston KPro and AlphaCor KPro sandwich a donor corneal graft between plastic plates. Complications can include melting/extrusion of the implant, infection, glaucoma, retinal detachment, and formation of membranes behind the implant. Close post-operative monitoring is required to manage complications and maintain vision with keratoprosthesis implants.
Keratoprosthesis is a surgical procedure that replaces a severely damaged or diseased cornea with an artificial cornea to restore vision. The first successful keratoprosthesis implantation in a human was in 1859. Modern devices like the Boston KPro (types 1 and 2), AlphaCor KPro, and osteo-odonto keratoprosthesis are commonly used today. The Boston KPro uses a donor corneal graft sandwiched between a front and back plate made of polymethyl methacrylate. The AlphaCor is made of a biocompatible polymer and integrates with surrounding tissues. Complications include melts and extrusion, infection, glaucoma, retroprosthetic membranes, and retinal
Femtosecond lasers can be used to assist with cataract surgery by performing three key steps: creating a precise capsulotomy, fragmenting the lens, and making incisions. The laser uses ultrashort pulses to precisely cut tissue with minimal collateral damage. During femtosecond laser-assisted cataract surgery (FLACS), the laser performs several pre-operative steps, then the surgeon completes phacoemulsification and lens implantation manually. Potential advantages include more reproducible incisions and capsulotomies, decreased ultrasound energy, and reduced stress on zonules, but the procedure takes more time and has a higher cost than conventional cataract surgery.
This document summarizes a case of keratectasia that developed in a patient's right eye following LASIK surgery. Initially, the patient's vision was good in both eyes after bilateral LASIK, but over three years her vision deteriorated in the right eye. Examination revealed irregular corneal contour with inferior thinning and steepening in the right eye resembling keratoconus. This is a case of keratectasia, a serious complication where the cornea bulges out due to weakening from refractive surgery.
Lymphoma Made Easy , New Teaching LecturesMiadAlsulami
This lecture was presented today as part of our local Saudi Fellowship program. After three years of direct interaction with trainees and hematologists, I have started to develop an understanding of what needs to be covered. This lecture might serve as a roadmap for approaching and reporting lymphoma cases.
2024 07 12 Do you share my autistic traits_ - Google Sheets.pdfCarriePoppy
I made this spreadsheet when I was waiting for my autism assessment. It helped me determine that I probably have autism. When I did get tested, they (UCLA) told me I do, indeed, have Type 1 autism. You can use this spreadsheet to compare your experience to mine. I am a white woman, AFAB. My diagnosis is Type 1 autism with a pragmatic language deficit.
These are the class of Drugs that are used to treat and prevent cardiac arrhythmias by blocking ion channels involved in cardiac impulse generation and conduction. Class I drugs like quinidine and procainamide block sodium channels to prolong the action potential duration, while Class IB drugs like lignocaine shorten repolarization. Class III drugs like amiodarone block potassium channels to prolong the action potential. Calcium channel blockers like verapamil inhibit calcium influx. Other drugs include adenosine for paroxysmal supraventricular tachycardia, beta blockers for supraventricular arrhythmias, and atropine for bradycardias. Adverse effects vary between drugs but include arrhythmias, heart block and QT prolong
Introduction to Dental Implant for undergraduate studentShamsuddin Mahmud
Introduction to Dental Implant
Dr Shamsuddin Mahmud
Assistant Professor, Department of Prosthodontics
Nortth East Medical College (Dental Unit)
Definition of Dental Implant
A prosthetic device
made of alloplastic material(s)
implanted into the oral tissues beneath the mucosal and/or periosteal layer and
on or within the bone
to provide retention and support for a fixed or removable dental prosthesis.
Classification of Dental Implant
According to placement within the tissue
Blade/Plate form implant
According to Material Used
A) METALLIC IMPLANTS
Commercially pure Titanium
Cobalt chromium molybdenum
Titanium aluminum vanadium
Stainless steel
B) NON-METALLIC IMPLANT
Zirconium
Ceramic
Carbon
According to the ability of implant to stimulate bone formation
A) Bio active
Hydroxyapatite
Tri Calcium Phosphate
B) Bio inert
Metals
Parts of Dental Implant
Implant fixture
Implant mount
Cover screw
Gingival former/healing screw/healing abutment/permucosal extension
Impression post/impression transfer abutment
Implant analogue
Abutment
Fixation screw
Implant Fixture
Implant Mount
Connected to the fixture
Function: used to carry implant from its vital to the prepared osteotomy site either by hand or with a ratchet/ handpiece adaption
Cover Screw
component that is used to cover the implant connection during the submerged healing of the implant
Function: preserves the patency of the connection by preventing any soft tissue ingrowth in the connection
Gingival former/ Healing Abutment/ Healing screw
Screw/ abutment used to create the soft tissue emergence profile around the implant.
Time of placement:
During 1st surgery – One step surgery
After Osseointegration – Two step/stage surgery
Gingival former/ Healing Abutment/ Healing screw
Placed in the site 2-3 weeks for soft tissue healing
Function:
Create gingival emergence profile
Formation of biological width
Impression post/impression transfer abutment
component that is used to trans- fer the implant Hex position and orientation from the mouth to the working cast.
Types
Closed tray
Open tray
Implant analogue/
component which has a different body but its platform and connection are exactly similar to the implant. The analogue is used to replicate the implant platform and connection in the laboratory mode.
Abutment
Abutments
Advantages of Dental Implant Retained Prosthesis
Maintain bone height and width by preventing bone resorption
Maintain facial esthetics
Improve masticatory performance
Improve stability and retention of prosthesis
More esthetics
Increase survival times of prostheses
There is no need to alter adjacent teeth
Improve psychological health
Disadvantages of Dental Implant Retained Prosthesis
Very expensive.
Cannot be used in medically compromised patients who cannot undergo surgery.
Longer duration of treatment
Requires a lot of patient co-operation because of repeated recall visits are essential
INDICATION OF DENTAL IMPLANT
Dental implants can successfully restore all
Introduction of mental health nursing, Perspective of mental health and mental health nursing, Evolution of mental health services, treatment and nursing practices Mental health team, Nature and scope of mental health nursing, Role & function of mental health nurse inn various settings and factors affecting the level of nursing practice, concept of normal and abnormal behavior
this presentation is all about vital force . this is the useful information for the students of homeopathy streamhyddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjvgggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg .
General Endocrinology and mechanism of action of hormonesMedicoseAcademics
This presentation, given by Dr. Faiza, Assistant Professor of Physiology, delves into the foundational concepts of general endocrinology. It covers the various types of chemical messengers in the body, including neuroendocrine hormones, neurotransmitters, cytokines, and traditional hormones. Dr. Faiza explains how these messengers are secreted and their modes of action, distinguishing between autocrine, paracrine, and endocrine effects.
The presentation provides detailed examples of glands and specialized cells involved in hormone secretion, such as the pituitary gland, pancreas, parathyroid gland, adrenal medulla, thyroid gland, adrenal cortex, ovaries, and testis. It outlines the special features of hormones, differentiating between peptides and proteins based on their amino acid composition.
Key principles of endocrinology are discussed, including hormone secretion in response to stimuli, the duration of hormone action, hormone concentrations in the blood, and secretion rates. Dr. Faiza highlights the importance of feedback control in hormone secretion, the occurrence of hormonal surges due to positive feedback, and the role of the suprachiasmatic nucleus (SCN) of the hypothalamus as the master clock regulating rhythmic patterns in biological clocks of neuroendocrine cells and endocrine glands.
The presentation also addresses the metabolic clearance of hormones from the blood, explaining the mechanisms involved, such as metabolic destruction by tissues, binding with tissues, and excretion by the liver and kidneys. The differences in half-life between hydrophilic and hydrophobic hormones are explored.
The mechanism of hormone action is thoroughly covered, detailing hormone receptors located on the cell membrane, in the cell cytoplasm, and in the cell nucleus. The processes of upregulation and downregulation of receptors are explained, along with various types of hormone receptors, including ligand-gated ion channels, G protein–linked hormone receptors, and enzyme-linked hormone receptors. The presentation elaborates on second messenger systems such as adenylyl cyclase, cell membrane phospholipid systems, and calcium-calmodulin linked systems.
Finally, the methods for measuring hormone concentrations in the blood, such as radioimmunoassay and enzyme-linked immunosorbent assays (ELISA), are discussed, providing a comprehensive understanding of the tools used in endocrinology research and clinical practice.
These lecture slides, by Dr Sidra Arshad, offer a simplified description of the physiology of insulin and glucagon.
Learning objectives:
1. Describe the synthesis and release of insulin
2. Explain the mechanism of action of insulin
3. Discuss the metabolic functions of insulin
4. Elucidate the effects of insulin on adipose tissue, skeletal muscle, and liver
5. Enlist the factors which stimulate and inhibit the release of insulin
6. Explain the mechanism of action of glucagon
7. Discuss the metabolic functions of glucagon
8. Elucidate the role of insulin and glucagon in glucose homeostasis during the fasting and fed states
9. Discuss the role of other hormones in the glucose homeostasis
10. Differentiate between the types of diabetes mellitus
11. Explain the pathophysiology of the features of diabetes mellitus
12. Discuss the complications of diabetes mellitus
13. Explain the rationale of oral hypoglycemic drugs
14. Describe the features of hyperinsulinemia
Study Resources:
1. Chapter 79, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 24, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 39, Berne and Levy Physiology, 7th edition
4. Chapter 19, Human Physiology, From Cells to Systems by Lauralee Sherwood, 9th edition
5. Chapter 3, Endocrine and Reproductive Physiology, Bruce A. White and Susan P. Porterfield, 4th edition
6. Insulin and Insulin Resistance, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1204764/
7. Complications of diabetes mellitus,
https://pdb101.rcsb.org/global-health/diabetes-mellitus/monitoring/complications
STRATEGIES FOR RATIONALISING/REDUCING CAESAREAN SECTION RATE BY USE OF "SION ...Niranjan Chavan
The journey to reduce/rationalise the C-section rate started in June 2023 and it’s an ongoing study been carried out at #SionHospital #LTMMC Mumbai.
It’s going to revolutionise the journey of motherhood for safer, predictable maternal and fetal outcome.
The SION model is a structured and networked approach to promoting vaginal deliveries.
By integrating education, support, policy implementation, and continuous improvement, it aims to enhance maternity care and reduce unnecessary C-sections through collaborative efforts among healthcare providers and patients.
Encouraging trials of labor after previous C-sections (TOLAC) and fostering a multidisciplinary team approach in maternity care are crucial.
Regular training for healthcare providers and establishing supportive hospital policies further promote vaginal births.
Hemodialysis: Chapter 11, Venous Catheter - Basics, Insertion, Use and Care -...NephroTube - Dr.Gawad
- Video recording of this lecture in English language: https://youtu.be/QeWTw_fYPlA
- Video recording of this lecture in Arabic language: https://youtu.be/fUWI9boFc7w
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Heart Valves and Heart Sounds -Congenital & valvular heart disease.pdfMedicoseAcademics
This presentation, authored by Dr. Faiza, Assistant Professor of Physiology at CIMS Multan, delivers an in-depth analysis of heart valves, heart sounds, valvular heart diseases, and congenital heart defects. It begins by distinguishing between normal and abnormal heart sounds, elucidating the timing and causes of the four heart sounds—S1, S2, S3, and S4—and their clinical significance. Detailed explanations are provided on the auscultation sounds that define conditions such as mitral stenosis, mitral insufficiency, aortic stenosis, and aortic insufficiency, with a focus on how these pathological changes affect cardiac mechanics and blood pressure.
The presentation delves into abnormal heart sounds, known as murmurs, categorizing them by their causes, which include valvular lesions, rheumatic fever, aging, congenital heart diseases, viral infections during pregnancy, and hereditary factors. It explores the various types of murmurs, their timing within the cardiac cycle, and their association with specific valvular heart diseases such as stenosis and regurgitation. The intricate relationship between systolic and diastolic murmurs and conditions like anemia and ventricular septal defects is also highlighted.
Further, the presentation covers the pathophysiology of congenital heart diseases, offering a comprehensive review of conditions such as Tetralogy of Fallot and Patent Ductus Arteriosus. It explains the mechanisms of these diseases, their impact on cardiac function, and the clinical manifestations observed in affected individuals. The physiological adjustments of the circulatory system during exercise in patients with valvular lesions are discussed, emphasizing the reduced cardiac reserve and the risk of acute pulmonary edema.
Special attention is given to the compensatory mechanisms of the heart in response to valvular diseases, including the development of concentric and eccentric hypertrophy, increased venous return, and the eventual progression to heart failure. The presentation also examines rheumatic valvular lesions, aging-related aortic stenosis, and the specific challenges posed by these conditions, such as reduced stroke volume and increased metabolic demand.
This thorough exploration of heart sounds, valvular diseases, and congenital defects is designed to enhance understanding and clinical acumen, making it a valuable resource for medical students, healthcare professionals, and educators in the field of cardiology and physiology.
Interventional radiology is a medical specialty that uses imaging techniques, such as X-rays, CT scans, and ultrasound, to guide minimally invasive procedures to diagnose and treat a variety of conditions. These procedures can be an alternative to open surgery, often resulting in shorter recovery times for patients.
An exciting session emphasizing the timely intervention and management of obstetric sepsis for better patient outcomes.
This presentation highlights risk factors, diagnosis, management, and some interesting cases of obstetric sepsis.
Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may also be called vermifuges or vermicides
Definition of mental health nursing, terminology, classification of mental disorder, ICD-10, Indian Classification, Personality development, defense mechanism, etiology of bio psychosocial factors,
5. Keratoconus is a non-inflammatory, progressive,
bilateral thinning disease of the cornea
It is characterized by the development of a protrusion
of corneal apex often located centrally or in an
inferior eccentric position
usually presents in 2nd decade of life
The exact etiology is unknown, Both genetic and
environmental factors are associated with KC.
6. • 5 to 6 layers of stratified squamous non
keratinized epitheliumEpithelium
• A narrow acellular homogeneous zoneBowman’s
Membrane
• A regularly arranged lamellae of
collagen bundlesStroma
• A strong resistant sheet that’s
considered the basal lamina of the
corneal endothelium
Descemet’s
Membrane
• single layer of hexagonal cells at
posterior aspect of Descemet's
membrane
Endothelium
• Acellular in the pre-Descemet's cornea.
Separating Descemet’s from the last
row of keratocytes
Dua’s Layer
9. progressive painless decrease in vision
due to progressive astigmatism & myopia
The patient notices frequent change of
glasses& intolerance to C.L.
10. *According to K reading
Mild <45D in both meridians
Moderate
Advanced
Severe
45D to 52D in both meridians
52D to 62D in both meridians
>62D in both meridians
11. *According to shape of the cornea
small near-central ectasia of 5 mm in diameter or
less .
Displacement of the corneal apex below the midline
results in an island of inferior mid-peripheral
steepening.
This form of the disease affects nearly three-quarters
of the corneal surface.
13. distortion of the rings of the
Placido disk
The scissoring effect of red
reflex with streak retinoscope
Mild Keratoconus
14. distortion of the rings of the
Placido disk
The scissoring effect of red
reflex with streak retinoscope
Suspicious Corneal topography
Mild Keratoconus
16. Visible thickened corneal nerves
Fleischer's Ring:
A brown ring present at base of cone
best detected by cobalt blue filter
Moderate Keratoconus
17. Visible thickened corneal nerves
Fleischer's Ring:
A brown ring present at base of cone
best detected by cobalt blue filter
Lines of Vogt:
Small vertical stress lines disappear
with gentle pressure on globe
Moderate Keratoconus
18. Corneal Thinning:
the cone is often displaced inferiorly.
The steepest part of the cornea
(apex) is generally the thinnest
Moderate Keratoconus
19. Corneal Thinning:
the cone is often displaced inferiorly.
The steepest part of the cornea
(apex) is generally the thinnest
Corneal Scarring:
Sub-epithelial corneal scarring may
occur because of ruptures in
Bowman's membrane
Moderate Keratoconus
20. Munson's sign:
The corneal protrusion may cause
angulation of the lower lid on
downgaze in V-shaped conformation
Advanced Keratoconus
21. Munson's sign:
The corneal protrusion may cause
angulation of the lower lid on
downgaze in V-shaped conformation
Rizzuti's sign:
a sharply focused beam of light near
the nasal limbus produced by lateral
illumination of the cornea
Advanced Keratoconus
22. Munson's sign:
The corneal protrusion may cause
angulation of the lower lid on
downgaze in V-shaped conformation
Rizzuti's sign:
a sharply focused beam of light near
the nasal limbus produced by lateral
illumination of the cornea
Acute Corneal hydrops:
when Descemet's membrane ruptures,
aqueous flows into the cornea causing
edema and opacification
Advanced Keratoconus
24. The Pentacam was originally introduced as an
anterior segment analyzer that utilizes the
Scheimpflug photography technique.
When performing a scan, two cameras are used
to capture the image. One centrally located
camera detects pupil size, orientation and
controls fixation. The second rotates 180
degrees to capture 50 images of the anterior
segment to the level of the iris, and through the
pupil to evaluate the lens.
31. Sagittal Curvature Map Front Elevation Map
Pachymetry Map Back Elevation Map
Patient & Exam data
Ant Corneal Surface
Post Corneal Surface
Corneal Thickness
Pupil Diameter,
AC depth, IOP
34. Sagittal Curvature Map
Central K > 47.2 D
Difference between superior & inferior K > 1.9 D
Isolated area of steepening (Hot Spot)
Diagnois of
Keratoconus
35. Elevation Maps
Anterior Elevation Map
Central readings of 12 mm are suspicious
Central readings of 15 mm are diagnostic
Posterior Elevation Map
Central readings of 17 mm are suspicious
Central readings of 20 mm are diagnostic
Diagnois of
Keratoconus
36. Pachymetric Progression display
Diagnois of
Keratoconus
• Quick downward deviation in corneal spatial
thickness profile
• Progression index average > 1
• Irregularity Indices
• Keratoconus level box
37. Detect who is at risk of
developing postopeative
ectasia
Detect form froste
keratoconus
41. In the early stages of keratoconus, visual correction may be adequate
with astigmatic spectacles.
As the condition advances, and the cornea becomes more distorted and
contact lenses become a more suitable option.
Contact lenses create a more uniform refracting surface and decrease
surface irregularity.
Lens Types include :rigid lenses, soft lenses and combined use of both
rigid and soft lenses.
42. (RGP) lenses have ability to permit oxygen to
diffuse into, and Carbon dioxide to diffuse out of
the lens
1- Discomfort
2- Giant papillary conjunctivitis
3- Corneal wrapage
4- Corneal scarring
5- Keratitis
1- Longer wearing time.
2- Reduced corneal edema
3- Rapid adaptation.
4- More Oxygen permeability
5- Larger optic zone offers
increased visual field.
ComplicationsAdvantages
43. It consists of
1- soft lens(carrier) against the cornea to provide comfort
2- rigid lens(optical)over the soft to achieve vision
It consists of
1- (soft) skirt with water content of 28%
2- (rigid) optical center made of gas permeable material
These lenses provide the optic of a rigid lens, and the
comfort and good centration of a soft lens.
44. Characters:
1- Smaller posterior optic
2- Aspheric design of the periphery
Advantages :
1- provide a minimal central corneal touch
2-reduction in tear pooling at the base of the cone
Characters:
Large lenses that rest on the sclera
Advantages :
1- Increase in lens wearing comfort
2- Increase lens stabilization
Disadvantages :
Decreased visual acuity when compared to CCLs
45. Contraindications of CL
• Dry eyes and lid problems such as active blepharitis, stye & chalazion.
• Acute and chronic conjunctivitis, corneal abrasions, 5th nerve paralysis,
uveitis and iritis.
Lens type selection
Depending on level of Keartoconus :
Nipple cone keratoconus can be treated with glasses, soft
contacts, hybrid lens and gas permeable lenses. As the cornea steepens,
the gas permeable contact lenses is the best choice. Their contacts are
large enough to cover the steep cone area and improve vision.
Oval cone best fitted with lenses of larger diameters which have
larger optical zones e.g Scleral lenses
Globus cones are best to fitted with RGP lens of large diameter or
scleral lens, to vault over the big, steep area of cone.
46. They act as passive spacing elements that
shorten the arc length of the anterior corneal
surface and therefore flatten the central
cornea
When ectasia progresses to the point where
contact lenses no longer provide satisfactory
vision, then surgical intervention may be
considered. New methods such as intrastromal
corneal ring segments have evolved
47. A - Ferrara rings
• has a triangular cross section
• It requires 2 corneal
incisions
• It is implanted at 80% depth
• Smaller optical zone
B - Intrastromal
corneal ring segments
• has a hexagonal cross section
• are inserted through a 1.8
mm radial incision in superior
cornea near the limbus
• It’s implanted at two-thirds
corneal depth
• Larger optical zone
49. *Topical anesthesia.
*Marking the centre of cornea
*Intra-operative Corneal pachymetry
*radial incision 1.2 mm long at a depth of 70% of the pachymetry
*lamellar corneal dissection.
*create curved peripheral corneal tunnels >>>
*Application of a vacuum centering guide (VCG)
*The two intrastromal tunnels prepared using clockwise
and counterclockwise dissecting instruments.
*Each of the Intacs manually rotated into the tunnel
until the desired position was reached>>>
*The incision closed using a single 10-0 nylon
Procedure
50. DSIADVANTAGESADVANTAGES
A – Intraoperative
1-Anterior and posterior
perforations during channels
creation
2-extension of incision towards
visual axis
3-uneven or shallow placement of
implant
B – Postoperative
1- Undercorrection or Overcorrection
2- Induced astigmatism
3- Neovasularisation toward the
incision
4- Infection and melting
5- Glare and halos
6- Acute Corneal Hydrops
1-Safe
2-Effective
3-Rapid Effect
4-Adjustable
5-Reversible
51. *Tunnel depth two thirds the corneal thickness
*The entry wound opened with a blunt Sinskey
hook.
* Each of the Intacs then manually rotated into
the tunnel until the desired position was
reached.
* The incision closed using a single 10-0 nylon
suture.
Technique
52. DSIADVANTAGESADVANTAGES
1- Incomplete ring channel
formation
2- Endothelial perforation
3- Migration of ring segments
4- Infection
1-Different, depths, widths and
diameters, defined in advance.
2- Centric and eccentric laser cuts
can be performed
3- Corneal stress is minimal,
because only moderate pressure is
exerted on the eye during surgery
4- Risk of infection is significantly
reduced
53. After the formation of a closed pocket of 9 mm in diameter and
300 μm in depth within the corneal stroma, a flexible full-ring
implant is inserted into the corneal pocket via a narrow incision
tunnel
Intacs SK, Severe Keratoconus, is a newer design of ICRS with a
smaller 6mm optical zone to correct higher grades of keratectasia
with an elliptical cross-section to minimize the glare
Using femtosecond laser to create the tunnels decrease
postoperative spherical, coma and other higher order aberrations
A new Ferrara ring with a 210° arc. The new model has three
advantages over the conventional ring: (1) minimal astigmatic
induction, (2) more corneal flattening (3) implantation of a single
segment
Recent Advances
55. 1-Topical anesthesia of the eye.
2- Mechanical removal of epithelium
3- 0.1% riboflavin solution is applied manually
every 2 minutes, starting 30 minutes before
UVA exposure to allow stromal saturatuion >>>
4- Ultraviolet A (UVA) is used to deliver an
irradiance of 3 mW/cm2
5- The irradiation is performed from a distance
of 1cm for 30 minutes >>>
6- Repeated applications of riboflavin to the
cornea are performed every 2 minutes during
irradiation.
Procedure
58. Combining riboflavin with Intacs augmented the flattening effects of Intacs.
In progressive keratoconus first CXL was performed to stabilize keratoconus and then after 1 year
interval of stability, topography-guided PRK was performed to improve functional vision
Athens Protocol, CXL combined with topography-guided partial PRK followed by application of
mitomycin-C 0.02%
Rapid treatment protocols (10 min at 10 mW/cm2) showed equivalent increases in corneal
stiffness in comparison with the standard protocol (30 min at 3 mW/cm2).
Transepithelial CXL, in which riboflavin is delivered using enhancers of epithelial permeability
rather than epithelial debridement, It has benefits of standard epithelium-off treatments without
the painful rehabilitation and complications of epithelial removal.
Depth and extent of anterior corneal stroma changes induced by CXL could be determined using
high-resolution anterior-segment optical coherence tomography (OCT) post-operative images.
Recent Advances
59. 1) Contact lenses intolerance
2 ) Central corneal scar
3) Progression of the cone after Intacs
4) Recurrent keratoconus (after DALK)
Indications
Note
Acute hydrops is not necessarily an indication for
penetrating keratoplasty, because in many cases the
hydrops resolves and the resultant scar is outside
the visual axis. The scarring may flatten the cornea,
allowing the patient to tolerate contact lenses and
achieve good vision.
60. 1- General Anesthesia
2- Trephination
3- The graft cut from the endothelial side
4- The recipient cornea cut from the epithelial
side
5-The graft temporarily fixed using 10-0 nylon
sutures at the 3, 6, 9, and 12 o’clock position
6-Definitive fixation of the graft performed with
one of three suturing techniques; interrupted,
double running, and single running
Procedure
61. DSIADVANTAGESADVANTAGES
1-Graft rejection
2- Residual myopia
3- Post keratoplasty astigmatism
4-Late progression of astigmatism
5-Fixed dilated pupil
6-Recurrence of keratoconus
7- Endothelial loss
8-Transmitted infection
9-complications of intraocular
surgery such as glaucoma, cataract
formation, retinal detachment,
cystoid macular edema,
endophthalmitis, and expulsive
hemorrhage.
1-Effective
2- Good visual results
3- Stop progression
62. In keratoconic eyes the endothelium cell count is
usually good.
In DALK Descemet’s membrane and endothelium of
the host are preserved thus decreasing the incidence
of rejection
63. (a)Air injection deep into the stroma with
a bevel-down 27-G needle
(b)Round big-bubble formation passing
the trephination borders
(c) Formed big-bubble
(d)Exposed Descemet’s membrane after
removal of the corneal stroma
(e)Removal of donor Descemet’s
membrane
(f) suturing the graft
64. (A)The corneal diameter is marked using a
manual trephine
(B) A 2 mm corneal incision at the 12-
o'clock position is performed
(C) Trephination of 70% of the corneal
thickness
(D)The superficial lamella is removed using
a crescent knife
(E) Starting from the deep corneal incision,
a peripheral pocket is created using a
sharp disc knife
(F) A full diameter peripheral pocket is
created using a sharp disc knife and
Vannas scissors
(G) A blunt spatula is used to reach a deep
pre-Descemetic plane in the central 7
mm of the cornea.
(H)A continuous 10.0 nylon running suture
is placed
65. Microkeratome is used to perform both the recipient
bed dissection and lamellar dissection of the donor
cornea
Technique :
Shaving off the superficial 250 μm of the
keratoconic cornea by a microkeratome
The 350 μm donor lenticule is sutured on to the
recipient bed
The advantages :
*smooth graft–host interface
*technically easy procedure compared with DALK
*it can be used with corneal thickness ≥380 μm.
Before
After
66. DSIADVANTAGESADVANTAGES
1)-More complex procedure
2)-Longer operating time
3)- Descemet’s membrane
perforation
4)-Double anterior chamber
5)-Recurrent keratoconus
6)- Rise in intraocular pressure
7)- Fixed dilated pupil following
deep lamellar
(Urrets-Zavalia syndrome(UZS))
1)-No endothelial rejection
2)-Extraocular
3)-Stored cornea can be used
4)-Less topical steroids course
5)-Faster visual recovery
6)-Strengthen the cornea
7)- Rapid wound healing
67. *Femtosecond (FS) laser is used for creation of shaped
corneal incisions.
*complex patterns of laser trephination cuts include
A-Standard
B-top-hat
C-mushroom
D-zig-zag
E-Christmas tree
*All of these wound configurations
create more surface area for healing
improve tissue alignment
require less suture tension for alignment of tissue
have superior biomechanical strength
rapid visual recovery
68. any condition preventing proper laser docking such as
severe ocular surface irregularity
elevated glaucoma filtering bleb
glaucoma shunt implant
small orbits
extremely narrow palpebral fissures
recent corneal perforations
Contraindications
69. ADVANTAGES DSIADVANTAGES
Top Hat cut
• improved wound seal and
stability due to its internal
flange
• less astigmatism
Muschroom cut
• provide greater anterior
stromal replacement
Zigzag cut
• the most biomechanically
sound incision pattern
• less potential for tissue
misalignment and overall
optical distortion
• improved seal of the incision
site, improved tensile
strength of the wound &
faster wound healing
Top Hat cut
• possibility of tissue
misalignment
• posterior wound gap
Muschroom cut
• ring-shaped microcystic
edema over the interface of
the graft-host overlap zone
• protrusion of the anterior
lamella between sutures
associated with ointment
deposits and bacterial
infiltrates
71. Keratoconus is a degenerative, non-inflammatory
disease of the cornea, characterized by central
and para-central thinning and subsequent
ectasia
Corneal topography represents a significant
advance in the measurement of corneal
curvature over keratometry. Topography provides
both qualitative and quantitative evaluation of
corneal curvature.
New pathways for keratoconus management
address two essential aims: shape stabilization
and visual rehabilitation.
72. Shape Stabilization is achieved by Cross Linking which is
thought to stop the corneal ectatic disorder, new modalities
include Rapid CXL, Transepithelial CXL, Simultaneous CXL and
Topo-guided PRK.
Visual Rehabilitation is achieved by contact lenses in early stage,
Intrastromal corneal ring segments which are effective in
flattening the corneal shape and improving vision, novel
modalities include combined ICRS and CXL, INTACS SK and use of
Femtosecond laser to create channels for INTACS insertion.
Keratoplasty is the only treatment for advanced keratoconus with
corneal scarring. Recent advances include lamellar keratoplasty
techniques and the advanced shaped side-cut techniques,
particularly with the use of femtosecond lasers.
It combines elevation maps and pachymetry map to detect early ectasia
In keratoconus the cone is more pronounced
the goal was to design a reference surface that more closely approximates the individual’s normal cornea, and then to compare the actual corneal shape to this new reference shape. That is done through defining a reference surface based on the individual’s own cornea after excluding the conical or ectatic region
This is done by excluding a 4 mm optical zone centered on the thinnest portion of the cornea (cone) (exclusion zone),
Exclusion maps result from diff in elevation between standard and enhanced BFS