Lecture 6 Part 3 PDF

71 This is an OCT for patient who is cornela transplant because in the junction on the left side you can see there is a incision made The peripheral tissue of the host is thin and the donor tissue is the thickest The junction by the upper lid where there is graft tissue is (right) à there is a eleva...

71 This is an OCT for patient who is cornela transplant because in the junction on the left side you can see there is a incision made The peripheral tissue of the host is thin and the donor tissue is the thickest The junction by the upper lid where there is graft tissue is (right) à there is a elevation in the epi layer and there is space between epi and underlying stroma and there are vacuoles in the stroma. The person ears scleral lenses due to the post-surgical irregularities of the cornea. Top of edge of the scleral lens is thick due to high minus There is edema on top of the cornea due to the thick scleral and the lid closing on top of it and her transplant were 35 yrs old and she wears scleral lens à she has haziness more in the right eye Superior corneal region was hazier than graft and host tissue inferiorly so it shwos early edema. She was given Muro which can deswell the cornea and it can work better if the edema is superficial but if the edem ais stromal it wont work as well Muro can cause there to be less inflammation as well Avg age for cornela transplant is 25 yrs. Pt who have keratoconus have white and quiet and they just have cornela problem without virus etc then 71 their survival of their transplant is longer than 25 yrs but for herpes it will be less. Thos epts have trauma and herpectic disease do worse with the survival of the transplant tissue and they will have graft fail sooner because of the potential reoccurance of the herpetic virus Patients who have trauma have distortion She had cataract surgery and if she had new transplant done then we would need to wait a year to get the lens There are multiple manufactures for soft lenses and multiple materials but for gp and scleral lenses are limited. The button for the gp and scleral lenses is what the lens is made from She was fit with contamac optimum extra with dk value of 100 (52) We want to give scleral lens with highest dk value in effort to avoid edema 71 Average Corneal Thickness 72 The avg central thickn is 550 micron and varies from pt to pt and gender to gender you expect the thickness to increase as you go peripheral cornea 72 Top space: Scleral lens Mid layer: post lens tear layer Bottom layer normal thickness cornea 73 New slide: we use anterior seg oct for scleral lenses. The top layer that is clear is the scleral lens. The thinner space below the scelrla lens is the post lens tear layer and you want the post lens tear layer to half the thickness of the sclerla lens and sometimes it can be as thick as the scleral lens Underneath is the cornea 73 74 sweollen epithelium and fluid trapped in the anterior stromal layer and uneven epi layer and there is fluid trapped in the regions. Since its ina anterior stroma it is like 10-15% swelling due to the 10-15% increase in thickness compared to original thickness 74 75 Top image on the left is a person with keratoconus because the corneal looks thick in one portion and thin in the apex of the cornea. The thinness is prolyl around 300 microns so the pt can have cornela hydrops event which will cause rupture in descemets membrane so all of the endo layer misisng centrally are no deswelling the conea so aq can go into the cornea and there is reflected image which means there is swelling in the cornwa Orange is thick rewgions and blue is thin regions And apex of cornea is 300 75 Corneal Hydrops: rupture of endothelial layer, allowing Aqueous to enter cornea creating swelling and clouding 76 In the cases of hydrops, you will give muro but not sure if it will go this deep in the cornea. We also need to give them steroids because it can causes inflammatory response and they will have light sensivitiy due to the scatter of light that is trying to travel or there is anterior chamber has cells/flare The fluid has no where to go but the anterior cornea so the posterior layer clear and the layer of edema move forward and there can be microcysts that ruptures creating physical discomfort and potential for infection Eventually endothelium will heal and the flaps will go closer to the stroma in most cases and in some cases there can be permenant gap/scar in the stroma due to losing a lot of endo cells but there might not be as well. We are trying to see does the edema go away with meds or will it interfere with their VA Sometimes the cornea cannot deswell on its own due to the pumping mechanism being disrupted but the rest of the cornea can be clear and the area that is not helped if it inteferrs with VA à then cornela transplant might be needed 76 The more than 15% swelling does not really happen with contact lens but it can happen in keratoconus and they can wear contact elns but the problem that they have is not due to the contact lens Ctaract surgery can cause light scatter, microcystic edema and they are not even cl lens wearer and it can be due to endo damage. If the pt has this much edema maybe we wotn do cl for them 76 77 *** samia creating the discomfort and pain the patient will report 77 78 If you were to do a pachymetry map for the one image shown before (slide with two img and eyes) you can see the increase in thickness in those regions as well such as inf and slightly temporal of the visual axis 78 79 This is a keratonic pt who had hydrop event and significant edema à there is 200 micron increase in thickness inf temporally and overt the 2 months that area has flattened and became thinnes as the healing process happens 79 80 In the OCT you can see irregularity and clarity due to the scar and for pinguecula as well you can see the tissue disruption 80 Subtle Signs of Corneal Edema Va ?? Over refraction ?? Keratometry ??? Patient Observations???? Slit Lamp observations??? 81 81 Subtle Evidence of Edema Decreased quality of Va O.R. of > -0.30D to return to original Va Corneal curvature >1.00D Steeper or distorted K’s Pt observes colored haloes around lights 82 This pt cma e in and there was a decrease in VA compared to what they had. Increasing in myopic correction for 40 yrs old can be due to cataract which is too early for 40 or it can be due to subtle evidence of edema due to the soft lenses being worn The lack of ability of getting to 20/20 when before they could before and there is alspo increase in myopia, cornela measurement were central corneal curve steepning a than the original measurement so the cornea is thicknening, and there is distorsion of Ks à all those are evidcen there is fluid trapped and edema in the cornea 82 Benefits of Confocal Microscope Non-Invasive In vivo imaging of live corneal tissue. Disease detection Corneal graft rejection 83 83 Confocal Microscope Applanate Cornea 84 84 Reasons for Endo Cell Loss Aging Trauma to endo during cataract surgery Advanced Keratoconus – Hydrops: Spontaneous rupture of endo due to corneal thinning- Endo scarring Fuch’s Endothelial Corneal Dystrophy – Genetic compromised endothelial cell Long term low Dk/t Contact lens wear 85 85 FDA Significant Adverse Events > 2 mm neo vessel into clear cornea CLARE CLPU Viral / Infiltrate Corneal Erosion GPC 86 Vascularization of cornea beyond 2mm 86 87 There is a lot of vascualrition and it is beyond limbus and it is in apex so has to be 6mm There are wbcs are being leakage leading to hazy cornea This ahs to be due to inflammatory response and not justd ue to cl but we are rrying to avoid this in cl wear The vessels are engorged 87 Unacceptable Corneal Vessels Grade 1: 1 mm corneal invasion: MILD Grade 2: 2mm MODERATE Grade 3: 3 mm Dramatic Grade 4: 4 mm Severe Buildup of lactic acid in corneal periphery Especially superior limbal vessels Infiltration of cornea surrounding vessels supports active process 88 Vasuclariton 1mm into the cornela form the translucent limbal border is mild but when you get 2 or 3mm of vessels increased into the cornea is significant because hter is sig oxygen deprivation going on and if not corrected it will be worse 88 Slit Lamp Measurement of Corneal vessels Length, Slit Lamp aperture controlled beam Clock position location Engorged / Thin vessel caliber Clarity/haziness of cornea surrounding vessels Active blood flow vs ghost vessels 89 Remove cl for a period of time Treat the eye with topical steroids’ Lubrication and antibiotics If there is epi compromise then wait for the eye to heal and you need to consider whether they should get gp lens or not but we aren’t sure because fi they had this much vascularization then it means they are non-compliant and we might hesitant to give them cl again Measure the length of how many mm into the cornela from the limbal corneal junction did it go to. Sometimes the vessels are seen in all clock position If they are thin vessels and then it may suggest it is a old insult leading to the vascularization If the cornea is hazy thn it will tell you it is an active process and the cornea is suffering from lack of Oxygen. If the vessels are clear and vessels are thin then it suggests that it is a older event from inflammatory event, we will consider fitting them into GP lens if it’s a old event vs if there are lot of vessels and its engorged and angry then we may wait until to see any 89 improvement before giving them a cl Some of the vessels as the eye calms down becomes ghost vessels, the lumen is there but the rbcs are not trapped there and ghost vessels can come back if there is insult to the eye 89 Treatment > 2 mm Vessel Growth D/C scl wear, temporary or permanent Refit into DW higher DK material Refit into GP lens wear Close moniotring 90 We will discontinue lenses to prevent worsening We will higher dk and maybe gp because there is more oxygen trasnmisison in gp compared to soft lenses Many pts who have vascular growth have distortion in their cornea and you may need to go with gp lenses since it may be good for oxygen transmission and gp lenses will cover up the irregularities of the cornea in relation to trauma and vessel growth 90 SEAL: Superior Epithelial Arcuate Lesion Mechanical rubbing of epi by stiff SiHy lens With in 1-3 mm of superior limbus Follows arc of upper lid Possible diffuse infiltration surrounding epi split Diffusion of fluorescein under epi 91 There can be splitting of the superior portion of the cornea or it can happen anywhere or can happen splitting of the epi layer Epi splitting can happen due to stiff lens and there can be friction between surface of the epi and lens. You have the lens sititng there and the pressure fom ht eupper lid follows the same arch and the stiffness of the lens causes there to be trauma on to the surface epithelium leading to the splitting 91 SEAL Treatment D/C lens wear 7-10 days Prophyactic Topical antibiotic Frequent PF lubrication Re-assess BC to cornea relation – Is original BC flat ? Refit into softer lens material 92 Lubrication of some kind is what can help them the most If you are reintroducing the contact lens then we look to see if the BC is too flat compared to the cornea due to the pressure form the upper lid If the bc is too steep then you have gap between inf surface of contact lens and cornea and that causes leakage of debris and epi cell debris to get trapped under the lens and not flushed out à easy to manage such as removing the lens, providing lubrication and antibiosis and then reevaluation of the improvement and find whats causing it such as change material or bc to prevent it happening again 92 Repeatable Arcuate Staining w SiHy Lens Wear 93 This is happening inf The splitting can happen anywhere 93 Arcuate Stain From Trapped Tears 94 This splitting is dramatic You need to think about if there is any debris trapped in the lens and that if there is not enough tear exchange and it is more likely to happen inf due to gravity 94 Possible Etiology of Arcuate 95 95 CLARE: Contact Lens Related Red Eye Believed to be inflammatory (non-infectious) response to toxin released by bacteria colonizing cl surface (Holden 1996 Grant 1998) Often associated with EW lenses with lack of tear exchange à – Those who keep them on for long time and those who are reused more frequently such as monthly lenses and those who are extending the wear of the lens and then the lens has the opp to tighten up because its not hydrating in the solution overnight – also there is accumulation of the biofilm of the pt protein lipids etc which increases and the waste products from the bacteria and the biofilm causes trapping of the debris underneath lenses leading to red eye Reduction in rate of CLARE from 15% to 2 % annually with Disp SCL (Kotow 1988) 96 Common occurrence Non-infectious but ifnlalamtroy response to the toxins released by cells or bacteria on the lens surface 96 Contact Lens Related Red Eye: CLARE Symptom: – unilateral ( or bilateral) eye pain upon waking – + mild blurred Va, +Tearing, +Photophobia Signs: – Diffuse bulbar & limbal hyperemia due to inflamamtion – 1 or more subepithelial infiltrates – Scattered or focal epi staining – areas where there are presce of bacteira or entrapment of the debris is likely to take place – Possible anterior uveitis – have deep quiet anterior chamber but it is uncommon but you can have a clare response with this 97. after waking up Discomfort These are lenses they sleep with Epithelial compromise and there can be mild blurred va 97 Treatment for CLARE Temporary or permanent D/C of cl Frequent lubrication Prophylactic topical antibiotic if + staining – If you see a lot of diffuse staining then this is given but this has relatively mild staining Refit into DW disposable or GP – 7-10 days later you can go back to lenswear and you would ask them to do DW and they can try 2 week instead of monthly lenses. You want to remove the lens that has biofilm on it and you want to introduce a lens without the debris – You can also give them gp but staying on soft lens can solev the problem improving the replacement schedule 98 Let the eye calm down 98 CL Giant Papillary (Bulbar) Conjunctivits: CLGPC Inflammatory resonse of upper tarsal Allergice reaction Reduction in rate of CLGPC with Disp SCL ( Grant 1991) 99 Seen in hydrogel lenses Or conventional lenses where the replcament was every like 12 months or planned replacement of 6 months or can be see in lenses replaced in 3 months We are talking about older lens and where the lenses are replaced monthly ata time due to the parameter for instance it’s a MTO lenses such as higher steeper power and high corneal curvature etc 99 Proposed CLGPC Etiology Proposed delayed hyperseneitivity (allergic) reaction to protein & lipid mucous deposit on material surface GPC response found in patients wearing prosthetic eyes, SCL, GP’s or exposed sutures Symptoms: – – – – – – Itchy lids Mucous discharge Excessive lens movement Blurred vision FB sensation redness Signs – Large papilliae upper lid – Stringy, ropy discharge – Unilateral or bilateral 100 ski[p. 100 Treatment for CLGPC Temporary or permanent D/C device Short term use of topical steroid and simultaneous us of topical antihistamine Refit into DD scl or GP Enhanced cleaning regiment if planned replacement lens – Sereine (15% alcohol) – Miraflow (15% alcohol) 101. Potential for lipid protein in the reusable lens is high leading to upper lid response and we need to discontinue lens wear and we can to more freiqnryly replacement lens if the pt is in mto lens and frequent replacement cannot be done so then you can do product that allows cleaning such as they are made for soft and gp lenses and the surfactant in the serene or muroflow – there is 15% alcohol and the presence of alcohol removes the coating on the lens surface and can be useful for pt who cannot replace lenses frequnely They need to clean at the right time and you rub after putting the serene alcohol based product and then you rinse away the alcohol as well the debris and the lens can be put into a solution such as optifree, clearcare etc then any alcohol that is present will be also diluted so the alcohol is not left. Pt sometimes do not rub the lens sometimes before disinfecting an they do the rubbing after disinfection à which can cause bruning of the eye So if you give them alcohol based cleaner for reduction of gpc, you need to tell them the rubbing is done after removing the lens before doing disnfection Pateints have gpc you can give them steroid/low dosage will reduce the inflammatory response and reduce the itch you cannot leave the patient on it 101 for length of time so we start them on steroid for a week and then we will introduce antihistamine as well so by the time the week is over and the thye are discontinuing the steroids then the antihistamine can kick in to not allow inflammation and mucus discharge 101 Contact Lens Peripheral Corneal Ulcer: CLPU Mostly associated with EW or CW (Grant1998) < 1.5mm whitish typically circular peripheral corneal infiltrate (CLPI would have been better) Due to proximity of the limbus, Dense infiltration of anterior stroma with absence of microorganisms non infectious, non-hypoxic, benign Unclear etiology, most likey antigen (bacteria)antibody reaction 102 Its not the dangerous ulcer and it is a microbial keratitis It is always peripheral!!! Rleated to cl wear, related to ew and cw or overnight wear of some kind meaning pt can be non-cmoliant It is located in the peirpehry and the body can provide wbcs to this region leading to inflammatory response They are superficial and don’t go below the epi surface and it can be dense as well as white due to the amount of inflammatory response being del;ivered and there is typically no bacteria present and thought of sterile ulcer and they are thought to be related to trap debris due to the overnight lenswear It can happen in the morning because redness and discomdrt happens then 102