Lecture 6 part2 PDF

Epi Hypoxia Resp=Mild Inflamation Mild Inflammatory response: Light scatter = < VA – Lack of compact cellular layer FB sensation due to Epi breakdown – Due to mild epi nerve stimulation Conjunctival Vessel engorgement in response to – epi acidosis, – > carbon Dioxide – > lactic acid Chronic Challeng...

Epi Hypoxia Resp=Mild Inflamation Mild Inflammatory response: Light scatter = < VA – Lack of compact cellular layer FB sensation due to Epi breakdown – Due to mild epi nerve stimulation Conjunctival Vessel engorgement in response to – epi acidosis, – > carbon Dioxide – > lactic acid Chronic Challenge: EW Acu 2 Contact 35 Light is scattreted so the pt will see halo around the light and rainbow affect They will have discomfrt 35 Stage 3 Treating Microcysts D/C lens wear, tid Muro 128 salt solution (2% or 5% salt soln or ung at bedtime) FB / Dry sensation as epi surface shows punctate staining as cysts surface Frequent lubrication, PFAT’s Prophylactic topical steroid antibiotic: day time & night time antibiotic ointment 2-3 months to resolve 36 Return to DW high DK lens, modest wear time. 36 Delayed Develop & Resolution Onset usually 6-8 weeks of O2 compromised Number cysts increase the longer the O2 compromise 12 weeks to clear after termination of O2 compromise 37 Microcysts does not show up until the extensive wear has been going on for a while because takes a awhuile for the aerobic material to affect the epi development. It willt ake several months to resolve 37 Managing Epi Microcystic Edema D/c lens wear until resolved – Increase # of cysts during the first 3-4 weeks Rebound Length of time to return to normal metabolism – Length of Hypoxia can = length to resolution – Possibly 12 weeks for cysts to resolve Lubrication & possible Antibiotic protection while epithelial surface heals Cornea Clear, Refit with – proper BC to insure lens movement, – Higher DK material – DW 38 Lens wear is discontinued and the the lengths of the time to recover can take 3-4 weeks because it depends on how long the microcysts edema has been ongoing when the patient is read then we can do the following shown on the slide. You need to edu the pt on the possibility of needing GP lens. The diameter of the gp lens si smaller so more surface area of the cornea exposed to oxygen lens and it will be healthy since there will be more movement 38 Long Term Effect of Epithelial Edema 1Reduced mitotic rate 2Compromised junctional integrity 3Persistant Epithelial fragility 4 Hypoesthesia 5 Persistant Microcysts 6 Risk of Microbial keratitis 39 ski[p 39 Case 2: Hx,Blood Shot Eyes 40 yo M, new pt, 25 yrs SCL hx Wears -6.00 Cooper BioMed 55 2wks FW Rpts blood shot eyes all the time, irritation – Onset: 1-2 years – Location: OU – Duration: constant Periodic Pain so pt removes for 1-2 days Colored Halo around lights 40 Oxygen permeability of cooper vision 55 à 55% water content and 55% tend to be hydrogel lens so you need to think do they have oxygen deprivation. He was in FW so you need to think about eye irritation which he is reporting 40 Case 2 : Objective DVRx -6.00 OU 20/50 -0.50 20/30 OD SCL inserted this AM, OS 4 days FW Biomicroscopy OD, OS – Grade1+ 2 injection 360, engorged limbal vessels – Central corneal haze – Constant + Tearing, yet irritated feeling – Central corneal lines that change orientation when pressing on bulbar ??? 41 You do overrefraction and the increase in diopter cannot get hom better than 20/30 The right eye had the lens just today and had the left eye lens for 4 days You would think the left eye looks worse than right eye 41 Stage 4: Chronic Stromal edema / Striae In addition to epithelial cysts Striae = 6% edema ( LaHood 1990) Individual Lamellar cells of stroma are swelling Appear thicker than adjacent cells Loss of compact nature of stroma precursory of deep stromal neo-vessels Loss of stromal clarity, reduced Va 42 He didn’t skip 42 > 6% Edema =Stromal Striae 43 There are lines such as horizontal and vertical as well as striation As you press on the inf bulbar conj then the lines can change in their orientation. This is because there is twice the edema and vision cannot go down to 20/20 and there are more injection and there are vertical lines on the anterior stoma and as you press on the globe you can change the orientation of the eye There are lamellar layers of collagen and those layers of tissue can hold fluids which causes vision to go down, light scatrrter since as the light passes the cornea there are layers of lammelar tissue that has swollen and thickened Ind layer of lamellar tissue are swollen leading to the vertical lines. The lamellar layer will be less opaque compared to the adjacent ones. If you press on the globe the orientation of the lamellar line changes because you are causing movement in the stroma. If these were corneal nerves and you pressed on the globe then the orientation would not change but for stromal edema causing lamellar lines would change when you suppress the globe 43 44 44 Stromal Edema 45 There are some lamellar layers of cell has increased their thickness and that’s what creates a line affect since they are hydrated so there will be increase in anterior to posterior thickness of the cornea since th stroma ahs swollen a lot If you do anterior oct you will see increase in thickness at the area of the edema 45 Stromal Edema = Deep Vascularization 46 46 Stimulus to Deep Corneal Vessels 47 We are in twice than normal edema (6%) and pt will have significant hypoxia Because the stroma is swollen and the structure is less compact and there will potential for deep vascular tissue which are heading toward the corneal apex 47 Stage 4: Treating Stromal Striae D/C lens wear Muro 128, 2 or 5% TID, 5% ung bedtime (for epi cysts, questionable if will deswell stroma) May take 2-3 months to resolve Topical Steroid to reduce inflammatory response, reduce potential neo-vessels – Prescribe this because the body is doing inflammatory response that’s why the vessels are going into the stroma so if we give steroid we will dampen the inflammatory response and lessen the growth of the vessels DW high DK lens or GP – Go into a higher DK lens and go into GP b/c they have higher optical level and diameter of the lens is 9-10mm vs 14mm and they move481mm in lens and that’s why there will be good post lens tera film exchange Carefully monitor lens wear Muro 128 is salt solution which comes ind rop or ointment and comes in diff conc If you put salt the salt will dry out the tissue, the purpose of the muro is to draw the fluid out the cornea but this is deeper in the cornea All the muro can sting because it is a wounded eye. If you are prescribing muro 5% in the ointment form it can sting and burn but it is something we try to deswell the cornea because the longer the swelling the more damage 48 49 Risk of the vascularization of the cornea is that when the blood vessel ruptures due to rubbing or injury then there will be bleeding and if the vessels were near the apex of the cornea then there will be blood staining which will not be able to be moved unless the pt gets corneal transplant Here the vessels is bleeding in amorphous shape and this is more peripheral which can be removed but with the vessels being near the apex you cannot 49 Deep Stromal Corneal Neo Vascularization advance 2-3 mm into stroma 50 Vessels are going to grow 2-3mm in to the stroma due to the amount of oxygen deprivation 50 Stage 4: Chronic Stromal edema Folds Due to increased thickness of stroma, Folds / rolls in stromal tissue Significant decreased and distorted Va Folds = 10-15 % edema 51 If their edema continues to worsen then the next level of edema is stromal folds where the thickened lamellar layer are doubling up and folding up on each other and it is more prominent in its appearance à there will be 10-15% edema When there are folds there will be 10-15% of edema and the folds will be very obvious 51 ~10% Edematous Folds 52 52 Stage 4: Treating Stromal tissue Folds D/C cl wear, topical Mura for epi cysts Topical Steroid to reduce inflammatory response DW soft high Dk lens or more likely GP Careful monitoring. Patient either has compromised corneal function or noncompliance with scl wear. 53 Tretament for the folds will be same as stromal stria 53 Serious Adverse Events Chronic corneal edema Microbial keratitis Fungal keratitis Acanth keratitis 54 54 Stage 5: Chronic edema & Endo Cell Loss Severe chronic edema Result of long term Chronic hypoxia – Possible contact lens abuse – Post cataract surgery ( damage to endo cells) – Post trauma (damage to endo cells) Loss of endo cells density & function, inability of cornea to deswell. Loss of corneal clarity 55 55 Stage 5: Treating Chronic endo cell loss Requires surgical Penetrating Kerato Plasty (PKP) or Deep Lamellar Keratoplasty (DALK) – Replacement of the endothelial cell layer If left untreated, cornea will become painful & opaque. 56 Often time they get penetrating keratoplasty to help the endothelial layer 56 >15 % Edema Loss of Transparency 57 There is so much swelling and fluid retention that the vision is opaque and there is 15% of corneal edema or greater The common etiology is usually with pt who had corneal transplant or cataract surgery so the endo tissue have been disrupted and they don’t function to deswell the cornea There is corneal hydrops disease where the cornea stretches where the deepest endo layer of the cornea ruptures and tears open and aq goes into the cornea. The endothelial pump is ruptured so cornea cannot deswell. In this cond à pt’s only two choice to help them see again is penetrating keratoplasty (remove the central 8mm of the cornea) or doing a deep lamellar replacement procedure where the endo cells that are damaged can be removed and a new endo layer is placed with the hopee it will reduce the edema Muro in this case would not help and we can wait to see if the endo layer heals and if within 6 months it doesn’t then they need surgery 57 Confocal Microscope: Layer by layer observation of the cornea Healthy Epithelial layer Healthy Endothelial Layer 58 The cells are small, uniform in size and in shape The second à the image is 572 micorn deep into the cornea so it is the endothelial layer The avg corneal thickness if 550 We are looking at the endothelial cells which are uniform in size and shape so it is healthy 58 Normal Endothelial Cell Mosaic 59 59 Abnormal Endothelium Polymorphism & Guttata 60 With abusive contact lens were it changes the size and shape of the endo cells size Black spaces are the loss of the endo cells and what remains is amorphous endo cells where the density is reduced so the pumping action is compromised so these type of pts will have edema 60 Progression of Endo cell Loss 61 There is change in shape or loss of the cells due to age or cl wear When many cells are lost then ist guttata which is seen in older pts where there is dropout in endo function and older pts are susceptibal stromal edema than epi edema 61 Bandage Lenses often used to treat edematous cornea with chronic epithelial breakdown 62 62 Assessment: Stromal Edema Long term corneal hypoxia Significant compromise to metabolism Epithelial Microcystic edema (>3.2% swelling) progresses to Stromal edema (>6% anterior stromal swelling) Due to fluid retention = loss of stromal clear compact nature = light scatter >6% swelling of Stroma = vertical Striae >10% swelling Stroma = Stromal Folds.LaHood D, Grant A 1990 63 You can use topicals to decrease the swelling. The stroma tissue is can be thickened due to absorption of water in the case of swelling of the stroma (in this case edema is 6%. And then when there is stromal folds which is more than 10% edema, pt can see still and the cornea is not opaque yet when it Is very opaque then it is beyond 15% edema which is hard to recover from 63 Managing Anterior Stromal Edema D/c lens wear until resolved ( 6-12 wks) Hyperosmotic: Muro 128 (1 gtt qid, ung qhs) Lubrication & poss Antibiotic protection when epithelial surface shows disruption Accurately document remaining superficial & deep stromal vessel – CLOCK position location – 1, 2 or 3 mm extent into the cornea Refit with – proper BC to insure lens movement, – Higher DK material – DW 64 You can do muro for edema but they have minimal affect if the edema is in the stroma Document any vessel growth you see and the appearance of the cornea around the vessels. if they are ghost vessels then its good but when the oxygen has been eliminated they can reactivate so you need to avoid that with high dk and gp lenses 64 Dk/t Levels for Safe Ext Wear Pappas et. al. 1998: Dk/t=125 x 10(-9) based on NO limbal hyperemia LaHood et. Al. 1998: DK/t=125 x 10(-9) produces 15 % edema Below 1000cell/mm2 leads to Loss of corneal clarity & vision. WHY ? Treatment requires PK Milky white cornea = obscured corneal detail 66 We do endo cell count before they do any anterior seg surgery so we can understand the potential for conrela swelling as they undergo cornela swelling 66 Confocal Microscopic View Individual layers of Cornea. Hospital Based 67 67 Edema Measured Clinically by Slit Lamp signs – >3.2 - < 5% looks like ? – >5% - 10% - 15 % looks like ? Research / Clinical : Pachometer / Pentacam – Normal corneal pachs = 550 um – If you Measure = 600 um – Amount edema= 10% 68 Normal central corneal thickness with pachymetry is 550 microns So if you had baseline of the thickness and then in the future date a new value of higher or thicker cornea such as 600 micron which will represent a 10% swelling and the 10-15% swelling there will be folds in the stroma You can document the changes of thickness with oct pachymetry there is stria which is harder to see and there is lower amount of edema and it is is seen in those with soft and scleral lens 68 69 Anterior seg oct magnified of cornela thickness Outermost layer is tera layer, epi layer and then bowmans is 15 micorn and the stroma is majority of the thickness and in this case the stroma is compact and its not swollen. The bulk of cornea is stroma tissue 69 70 With OCT you can get a pachymetry map which will give values of thickness in diff regions. In this region you can see central corneal region is thinnesst and in periphery the thickness increases. And the increase down on the bottom is 700 range which is drmataic change 70