-After the lens vesicle separates from the surface epithelium, a wave of mesenchyme forms the primary corneal stroma. -A second wave then forms the endothelium, which secretes the DM. -The DM, hence, has a potential plane of separation from the corneal stroma, which we use to our benefit in DMEK surgery and which works against us in an inadvertent DM detachment. ASSESSING THE DMD: -Must be suspected when unexpected corneal edema is noted on the day after surgery. -In the pres
-Myasthenia gravis is a post synaptic autoimmune disorder due to failure of neuromuscular transmission resulting from binding of autoantibodies to proteins involved in signalling at the NMJ. -OMG is where weakness is clinically isolated to the periocular muscles (extraocular muscles, LPS and orbicularis oculi). - Ocular muscles are involved in 97% of patients during disease. FEATURES: -Ptosis. -Diplopia. -Fluttering of ptotic eyelid observed during eye movements (Lid Hopping)
-Development of irreversible corneal edema after cataract surgery and IOL implantation. -Initially, there is endothelial trauma followed by progressive stromal and epithelial edema. -The epithelial edema results in the formation of bullae, hence the name bullous keratopathy. Want to know the etiology of PBK? LOOK ABOVE! www.ophthalmobytes.com Image from Rajan Eye Care Hospital #ophthalmology #cornea #ophthalmobytes #ophthal #doctor #health #medical #vision #education #opt
Tan et al. gave a morphological classification of pterygium based on its transparency under the microscope. LOOK ABOVE FOR THE GRADING! www.ophthalmobytes.com Image from Rajan Eye Care Hospital #ophthalmology #cornea #ophthalmobytes #ophthal #doctor #health #medical #vision #education #optometry #medicalstudent #optometrist #medicine #eye #ophtho #ophthalmologist #ophthalmo #med #medicaleducation #ophthalmologyresident #ophthalmologyresidency #apaoyo #pterygium #conjuncti
Descemet's Stripping Endothelial Keratoplasty! -In DSEK: the patient’s Descemet membrane is peeled off and replaced with a partial thickness graft: a transplanted disc of Posterior Stroma, Descemet and Endothelium. Both donor and host cornea are manually dissected. -In DSAEK: the donor dissection is carried out using a mechanical microkeratome. GOAL of DSEK: -To transplant a healthy endothelial cell layer that will pump the fluid out of the cornea. -Expected to restore cornea
-Symptoms are usually more than signs.
• Ocular surface disorders.
• Contact lens wear
• Drugs (Corticosteroids)
• Diabetes mellitus, HIV positive patients (immunocompromised states).
SLIT LAMP EXAMINATION:
-An epithelial defect with surrounding stromal infiltration which is usually different for different organisms.
-Suppurative stromal infiltration.
-Associated conjunctivitis is certain organisms (gonococcal, pne
•Bilateral, non-inflammatory, non-hereditary peripheral corneal thinning usually inferiorly (4 to 8 ‘o’ clock). ONSET: •2nd to 5th decade of life. PATHOPHYSIOLOGY: •Thought to be secondary to collagen abnormalities, similar to keratoconus. •The thin, weakened cornea is said to protrude as a result of intraocular pressure. SYMPTOMS: •Progressive deterioration of visual acuity due to irregular astigmatism. •Rare – pain due to acute corneal hydrops. SIGNS: •Peripheral band of co
•Bilateral lipid degeneration of the cornea. •Two forms: Primary & Secondary. Occurs mainly in secondary form. •May be peripheral/ central / diffuse. ETIOLOGY: •Accumulation of lipids may result from excessive production, impaired lipid metabolization or both mechanisms. RISK FACTORS: •Secondary to systemic disorders of lipid metabolism- Defects in cholesterol esterification, in lipoprotein scavenging, Fish-eye disease, Tangier disease. •Secondary form: associated with previo
𝐌𝐨𝐨𝐫𝐞𝐧’𝐬 𝐔𝐥𝐜𝐞𝐫 𝐌𝐚𝐧𝐚𝐠𝐞𝐦𝐞𝐧𝐭
The goal of therapy is to arrest the destructive process and to promote healing and reepithelialization of the corneal surface
1. 𝘛𝘰𝘱𝘪𝘤𝘢𝘭 𝘤𝘰𝘳𝘵𝘪𝘤𝘰𝘴𝘵𝘦𝘳𝘰𝘪𝘥𝘴 to control the inflammation
2. 𝘊𝘰𝘯𝘫𝘶𝘯𝘤𝘵𝘪𝘷𝘢𝘭 𝘳𝘦𝘴𝘦𝘤𝘵𝘪𝘰𝘯
● Conjunctiva adjacent to the ulcer contains inflammatory cells that may be producing antibodies against the cornea
𝐌𝐨𝐨𝐫𝐞𝐧’𝐬 𝐔𝐥𝐜𝐞𝐫 ● Mooren’s is a chronic, progressive and painful peripheral ulcerative keratitis of idiopathic/unknown etiology and no systemic associations. ● First described by Boman and McKenzie in 1854 as ‘chronic serpiginous ulcer/ ulcus rodens’ ● Autoimmune process - a Type 3 hypersensitivity reaction has been implicated - antigen antibody reaction to infectious toxin deposited in the peripheral cornea causes inflammation and ulceration ● More
Radial Keratotomy is a refractive surgery procedure to correct myopia
Developed in 1974 by Svyatoslav Fydorov
It is now obsolete and has been replaced by laser based refractive surgery procedures such as Photorefractive Keratectomy (PRK) and LASIK
● Series of 4-8 deep radial corneal stromal incisions in a spoke like pattern
● Starting from central optical zone (4mm) till the limbus in the mid-peripheral and peripheral cornea
𝘊𝘰𝘯𝘨𝘦𝘯𝘪𝘵𝘢𝘭 𝘏𝘦𝘳𝘦𝘥𝘪𝘵𝘢𝘳𝘺 𝘌𝘯𝘥𝘰𝘵𝘩𝘦𝘭𝘪𝘢𝘭 𝘋𝘺𝘴𝘵𝘳𝘰𝘱𝘩𝘺 (𝘊𝘏𝘌𝘋)
● Bilateral cloudy cornea at birth/perinatally
● Earlier classified as CHED 1 (AD) and CHED 2 (AR) - now CHED 1 has been eliminated by the International Classification of Corneal Dystrophies (IC3D)
● Chromosome 20p13 - SLCA411 gene - transmembrane protein from bicarbonate transporters family - works as a pump on the stromal side of endothelial cells
● Degeneration of end