The VF-14 index of functional visual impairment in candidates for a corneal graft.

PURPOSE: To validate the Visual Function-14 (VF-14) index of functional visual impairment in candidates for a corneal graft. METHODS: One hundred thirty-four patients who were candidates for a corneal graft participated in this study between August 1996 and February 1997. Demographic, ocular history, best-corrected visual acuity, and detailed ocular examination data were collected. Functional visual impairment information was obtained by telephone interviews using the following: VF-14, SF-36 (Short Form-36, a more generic measure of general health function), and Visual Symptom Score, and four questions measuring the overall amount of trouble with vision, dissatisfaction with vision, ocular pain, and discomfort. RESULTS: The average age of corneal graft candidates was 64 +/- 18 years (range, 18 to 90 years) and 60% were women. The most frequent corneal disease was pseudophakic bullous keratopathy (41%). Ocular comorbidities included glaucoma or ocular hypertension (30%) and cataract (19%). The mean best-corrected visual acuity of the eye scheduled for surgery was 1.33 +/- 0.56 logMAR whereas the best eye best-corrected visual acuity was 0.36 +/- 0.44 logMAR. The mean VF-14 score was 73% +/- 26%, and the internal consistency was high, with a Cronbach alpha value of 0.94. The VF-14 correlated strongly with the best eye best-corrected visual acuity. It also correlated strongly with the Visual Symptom Score, the global measures of trouble and dissatisfaction with vision. Candidates for a corneal graft had low scores for all eight general health concepts evaluated with the SF-36, and the VF-14 correlated with seven of the eight SF-36 subscales. CONCLUSION: The VF-14 is a valid measure of functional visual impairment in candidates for a corneal graft. The Visual Symptom Score and the SF-36 are also useful indices in such patients.

Role of presensitization and donor-recipient crossmatching in corneal graft outcome.

PURPOSE: A positive donor-recipient crossmatch (CM) due to preexisting recipient lymphocytotoxic antibodies is known to be an important factor in allograft failure in the majority of organ transplantations. However, the effect of positive CM on corneal graft outcome is less known. METHOD: Between 1982 and 1994, CM was performed by the microlymphocytotoxicity method using donor lymphocytes and recipient pretransplant serum in 759 consecutive corneal transplantations (maximal follow-up, 36 months). Patients were evaluated regarding the type of allospecificity of antibodies involved and their role on corneal graft outcome (rejection and failure). RESULTS: A positive CM was found in 61 patients (8%) and a negative CM in 698 patients (92%). The positive and negative CM groups had similar graft rejection rates at 36 months. Patients with a positive CM due to antibodies directed against donor human leukocyte antigen (HLA) (as defined on the basis of private and public or CREG HLA allele specificities) did not have an increased risk of rejection. However, patients with positive CM and presensitization (previous graft or rejection history) had a statistically significant increase in risk of corneal endothelial rejection. CONCLUSION: This study shows that donor-recipient CM could be a useful procedure for the selection of recipients for corneal transplantation in patients presensitized by anterior graft or previous corneal rejection.

Role of ABO and Lewis blood group antigens in donor-recipient compatibility of corneal transplantation rejection.

PURPOSE: There are conflicting results regarding the role of human leukocyte antigen (HLA) matching and ABO compatibility in corneal graft rejection for low- and high-risk patients. Lewis blood group antigens could be an important histocompatibility system. Beneficial effects of Lewis antigens matching have been reported in renal transplantation, but its effect is still unknown in corneal allografting. METHODS: Between 1987 and 1993, ABO, Lewis and HLA phenotypes were determined in 697 consecutive grafts of corneal transplantations. The effect of Lewis matching on corneal endothelial rejection was evaluated over a 3-year period. Data analysis was done by plotting survival curves with the Kaplan-Meier method for survivorship data and performing statistical analysis with the log-rank test (Mantel-Haenszel test) for curve comparison. RESULTS: In vascularized recipients, the ABO, Lewis, and HLA systems did not influence the graft outcome. However, for the unvascularized recipients, the endothelial 3-year rejection rate was significantly lower for both Lewis compatible patients (84% vs. 68%; log rank = 0.03) and HLA compatible patients (86% vs 72%; log rank = 0.001), but not for the ABO-matched patients (82% vs. 79%; log rank = 0.56). CONCLUSIONS: The authors' study suggests that Lewis antigens and HLA matching could positively influence corneal graft survival for the unvascularized recipients, but it did not seem to have any effect in vascularized recipients.

Risk factors of corneal graft failure.

PURPOSE: To measure the association between potential risk factors and corneal graft failure. Two failure outcomes are compared: those with and those without a prior immune allograft reaction. METHODS: Based on a single-center observational study design, 539 adult recipients of a corneal graft were followed for a median time of 30 months. Survival analysis was carried out. RESULTS: Eighty-two graft failures were recorded. Of 82 failures, 53 (65%) were not preceded by an immune allograft reaction. Presence of blood vessels in the recipient cornea was associated with a twofold increase in risk for both failure outcomes. Three factors increased the risk of failure without an immune reaction: prior glaucoma or uveitis (adjusted relative risk estimate = 3.1), vitreous surgery with the graft (adjusted relative risk estimate = 2.0), and a repeat graft in the study eye (adjusted relative risk estimate = 2.0). Conversely, large graft wound size (adjusted relative risk estimate = 2.0). Conversely, large graft wound size (adjusted relative risk estimate = 2.9) and human leukocyte antigen (HLA)-A, -B incompatibility (adjusted relative risk estimate = 2.2) were associated with failures that followed an immune reaction. CONCLUSION: In this study, the authors support the clinical impression that corneal graft failures with and without a prior immune reaction are distinct phenomena. Enhanced surveillance in recipients with glaucoma and early intensive treatment of allograft reactions are recommended to improve the outcome of corneal grafts.

Pretransplant and posttransplant antibodies in human corneal transplantation.

The purpose of this study was to measure the association between antibody formation and endothelial corneal allograft reactions in 533 consecutive corneal graft recipients. The median follow-up time of these recipients was 732 days. Pretransplant panel-reactive antibodies were not found to be associated with endothelial corneal allograft reactions. Out of 533 recipients, 239 developed posttransplant antibodies during the course of this study. The formation of posttransplant antibodies was frequent in recipients with pretransplant antibodies and in HLA-A,-B-incompatible recipients. Posttransplant antibodies most often appeared within the first six months after transplantation whereas endothelial allograft reactions most often occurred later. Out of 65 recipients who developed PPRA and underwent an allograft reaction, 53 had a PPRA peak prior to, or at about the time of, the allograft reaction. Corneal allograft reaction events diagnosed during the second and third year after surgery were correlated with PPRA formation during the first year after grafting. The 36-month reaction-free survival rate of transplants was estimated at 72% in recipients with PPRA compared with 86% in recipients without PPRA (log rank P value = 0.002). Furthermore, posttransplant antibody formation altered the outcome of corneal allografts in both HLA-A and -B-compatible and -incompatible recipients. These findings suggest that posttransplant antibody development represents a high risk of endothelial corneal allograft reactions.

Association between corneal allograft reactions and HLA compatibility.

The purpose of this follow-up study is to measure the association between corneal allograft reactions and donor-recipient HLA-A and HLA-B compatibility. Four hundred thirty-eight consecutive adult recipients of corneal grafts with known donor-recipient HLA matching were observed for allograft reactions and failures. Most of the recipients under observation (91%) were well matched for HLA-DR. Of 438 recipients, 158 (36%) completed a 3-year follow-up. Three factors were associated with endothelial allograft reactions: 2 to 4+ corneal vascularization (relative risk, 2.2; P = 0.0006), two mismatched antigens at either the HLA-A or HLA-B locus (relative risk, 2.1; P = 0.0009), and recipient wound size of 8 mm or greater (relative risk, 1.5; P = 0.05). Unexpectedly, a strong association between endothelial allograft reactions and HLA-A or HLA-B incompatibility was found in low-risk recipients defined as unvascularized recipients of a small graft (relative risk, 3.2; P = 0.004). A larger sample size is required to determine if HLA matching offers a solution for recipients with corneal vascularization.

Comparison of prednisolone acetate and indomethacin for maintaining mydriasis during cataract surgery.

Preoperative topical nonsteroidal anti-inflammatory drugs such as flurbiprofen and indomethacin have been found to maintain mydriasis during cataract surgery. Steroidal anti-inflammatory drugs are commonly used to treat postoperative inflammation, but their effect on the maintenance of intraoperative mydriasis is unknown. Forty-six patients admitted for elective cataract surgery were randomly assigned to one of three treatment groups and received 1% prednisolone acetate, 1% indomethacin or artificial tears four times before surgery, in addition to standardized preoperative dilating drops and intraoperative epinephrine. Pupillary diameter was measured and the time interval noted five times during the surgery. During surgery the indomethacin group lost significantly less mydriasis than the control group. The mydriasis losses of the prednisolone acetate group were between those of the indomethacin and control groups, but these differences did not reach significance. We conclude that prednisolone acetate is less effective than indomethacin for maintaining mydriasis during cataract surgery.

[Rejection following corneal transplantation. Effect of HLA compatibility of the grafts]. / Rejet suite à une transplantation cornéenne--effet de la compatibilité HLA des greffons.

One hundred and fifty-two consecutive corneal transplants were performed with recipients selected on the basis of the best HLA-A, B, and DR match, and observed for corneal transplant rejection episodes. Following a descriptive analysis of data, the transplants were subdivided into well matched transplants (109 cases) and poorly matched transplants (43 cases). The rejection rate of poorly matched transplants was 2.37 times higher than that of well matched transplants (p = 0.09). Analysis of survival curves, three years after transplantation, shows a 91% rejection-free survival of well matched transplants compared to 78% for poor matched transplants. These findings suggest that the risk of corneal transplant rejection may be reduced by optimal HLA-A, B, and DR matching.

Effect of factors unrelated to tissue matching on corneal transplant endothelial rejection.

We examined 348 consecutive adult recipients of a corneal transplant for clinical signs of an endothelial rejection episode in a single-center follow-up study. The variables studied included primary diagnosis, number of previous corneal transplants, previous transplant failures from rejection episodes, transplant size, recipient corneal vascularization, donor age, recipient age and sex, past blood transfusions, and number of pregnancies. Five important risk factors were identified: primary diagnosis of herpetic, interstitial, or traumatic keratitis; transplant size 8 mm and larger; more than one previous corneal transplant; recipients younger than 60 years of age; and the presence of recipient corneal vascularization. This information will serve eventually for analyzing the effect of donor recipient tissue matching on corneal transplant rejection.

HLA-A,B and DR matching in corneal transplantation.

One hundred eighty-five consecutive corneal transplants were performed in recipients selected on the basis of the best available HLA-A,B and DR match. Endothelial rejection-free transplant survival in this group was compared to a retrospective historical control group of 199 consecutive transplants performed in recipients selected on the basis of age and longest wait criteria. The two groups were comparable with regards to primary diagnosis, preoperative corneal vascularization, donor and recipient age, and operative techniques. Thirty-eight transplants in the study group and 28 transplants in the control group were at high risk for endothelial transplant rejection. At 12 months, the estimated rejection-free survival (Kaplan-Meier method) of the high-risk study group transplants was 87% compared to 74% for the high-risk historical control group and transplants. This difference did not reach the significant level of 0.05 with the log-rank test. The 12-month estimated rejection-free survival of low-risk study group and historical control group transplants were similar. In the study group, the 12-month estimated rejection-free survival of well-matched transplants was 95% compared to 83% for poorly matched transplants (log rank, P less than 0.02). These findings suggest that a relationship exists between HLA-A,B and DR compatibility of donor and recipient and the corneal rejection-free transplant survival.

Lamellar keratoplasty in the management of recurrent pterygium.

Our experience with excision and LK in ten cases of recurrent pterygia was reviewed. Although a recurrence occurred in three of ten cases, the new pterygia only partially involved the lamellar graft. Visual acuity improved in six cases. Lamellar keratoplasty following excision of recurrent pterygia seems to be a useful alternative in their treatment.

Diagnosis and management of Acanthamoeba keratitis.

Diagnosis and management of Acanthamoeba chronic ulcerative keratitis is difficult. Two cases of Acanthamoeba keratitis at Wills Eye Hospital were diagnosed within several months of each other during 1983. Corneal transplantation was necessary for diagnosis and therapy in these cases. Another two cases were diagnosed when histopathologic specimens from penetrating keratoplasties done between 1974 and 1983 were reviewed retrospectively. There has been no evidence of recurrent disease in any of our cases during follow-up periods averaging two years (range, 12 to 40 months). The diagnosis of Acanthamoeba keratitis must be considered in cases of chronic progressive corneal ulceration unresponsive to medical therapy.

Iatrogenic ocular silver nitrate burn.

Two cases of silver nitrate burn occurred after treatment of superior limbic keratoconjunctivitis with a solid silver nitrate applicator. After medical treatment and several months of observation, visual acuity eventually returned to acceptable levels with minimal corneal scarring. These cases emphasize the fact that silver nitrate should be used very cautiously around the eye and only in a fresh 0.5-1% solution. The use of solid silver nitrate should be prohibited around the eye.