PURPOSE: To determine the differences in visual fields during 42 months (3 1/2 years) of follow up between eyes treated with argon laser trabeculoplasty first and eyes treated with topical medication first in patients with newly diagnosed primary open-angle glaucoma.METHODS: Visual field examinations were obtained at enrollment, three and six months, and at six-month intervals thereafter during follow-up of 271 patients enrolled in the Glaucoma Laser Trial, Numeric analyses of the examination results, including global indices and patterns of localized changes, as well as masked subjective clinical impression, were used to compare the two treatment groups.RESULTS: The mean threshold for eyes treated with laser trabeculoplasty first was 0.3 dB better than that for eyes treated with topical medication first averaged over follow-up (95% confidence interval, [-0.1, 0.7]; P = .17), More eyes treated with topical medication first (82 [31%] of 261 eyes) than eyes treated with laser trabeculoplasty first (61 [23%] of 261 eyes) had confirmed localized deterioration at least once during follow-up (P = .02), Improvement was nearly twice as common as deterioration on masked subjective impression in both groups through 30 months (2 1/2 years), Eyes treated with laser trabeculoplasty first were judged to have slightly more improvement and slightly less deterioration than eyes treated with topical medication first.CONCLUSION: During follow up, measures of visual field status for eyes treated with laser trabeculoplasty first were slightly better than those for eyes treated with topical medication first, Statistical significance was attained for only some of the differences, and the clinical implications of such small differences are not known.

PURPOSE: To determine differences between the two treatment groups of the Glaucoma Laser Trial with respect to intraocular pressure, visual fields, optic disk cupping, and therapy for primary open-angle glaucoma.METHODS: The Glaucoma Laser Trial was a multicenter, randomized clinical trial designed to assess the efficacy and safety of starting treatment for primary open-angle glaucoma with argon laser trabeculoplasty vs starting with topical medication. The Glaucoma Laser Trial Follow-up Study was a follow up study of 203 of the 271 patients who enrolled in the Glaucoma Laser Trial. By the dose of the Glaucoma Laser Trial Follow-up Study, median duration of follow-up since diagnosis of primary open-angle glaucoma was seven years (maximum, nine years).RESULTS: Over the course of the Glaucoma Laser Trial and Glaucoma Laser Trial Follow-up Study, the eyes treated initially with argon laser trabeculoplasty had lower intraocular pressure and better visual field and optic disk status than their fellow eyes treated initially with topical medication, As compared to eyes initially treated with medication, eyes initially treated with laser trabeculoplasty had 1.2 mm Hg greater reduction in intraocular pressure (P < .001) and 0.6 dB greater improvement in the visual field (P < .001) from entry into the Glaucoma Laser Trial. The overall difference between eyes with regard to change in ratio of optic cup area to optic disk area from entry into the Glaucoma Laser Trial was -0.01 (P = .005), which indicated slightly more deterioration for eyes initially treated with medication.CONCLUSIONS: Initial treatment with argon laser trabeculoplasty was at least as efficacious as initial treatment with topical medication.

Data collected at enrollment on the 271 patients (542 eyes) who participated in the Glaucoma Laser Trial (GLT) were analyzed for subgroup differences. The subgrouping variables included four patient characteristics (race, sex, age, and history of a vascular disease) and one ocular characteristic (myopia). The strongest differences observed were between blacks and whites. As compared with the eyes of the white patients, those of the black patients had lower mean decibels per test location in the visual field (P < .001), greater mean defect (P < .001), number of abnormal test locations (P < .001), and corrected loss variance (P = .009), as well as greater cup depth (P < .001), and larger mean horizontal (P = .002) and vertical (P < .001) cup/disc ratios.

The Collaborative Corneal Transplantation Studies (CCTS) is a set of two multicenter clinical trials designed to investigate the efficacy of donor-recipient human leukocyte antigen matching and crossmatching. High-risk penetrating keratoplasty patients were enrolled through six clinical centers for either the Antigen Matching Study or the Crossmatch Study. All patients were subject to a common set of examinations, treatments, and evaluation procedures. Standard procedures for the identification of high-risk patients, administration of postoperative medications, and recognition and treatment of immunologic allograft reactions were developed and used successfully. These procedures may serve as guidelines for studies in corneal transplantation. Adoption of these methods by other investigators would facilitate evaluation and comparison of results.

BACKGROUND:After penetrating keratoplasty, many corneal surgeons adjust sutures to reduce astigmatism and then leave the sutures in place indefinitely. Nylon sutures can hydrolyze and break years after surgery. In a series of human penetrating keratoplasties, we studied the use of polyester (Mersilene) sutures that do not hydrolyze.METHODS:We performed two prospective studies of polyester (Mersilene) sutures in human penetrating keratoplasty done by one surgeon. Study I was a randomized comparison of combined running and interrupted Mersilene and nylon sutures in 45 consecutive eyes. Study II was a case series of single running Mersilene suture with postoperative adjustment of suture tension to manage astigmatism in 23 consecutive eyes. We evaluated the performance of the suture and the control of astigmatism.RESULTS:The interrupted running suture study demonstrated that interrupted Mersilene sutures were 5.5 times more likely to have handling-related complications than nylon interrupted sutures (p = .01); in addition, they were three times as likely to have tissue-related complications as nylon (p = .16). The running suture study demonstrated an unacceptable complication rate of 69% when Mersilene was used as a single adjustable running suture. At 6 months postoperatively, the median refractive astigmatism for the adjustable cases was 3.37 diopters (mean, 4.03 +/- 2.37 D). Eyes with significant suture-related complications were 2.85 times more likely to have greater than 4.00 D of refractive astigmatism than were eyes without suture-related complications.CONCLUSIONS:Mersilene is an undesirable suture for use in penetrating keratoplasty.

The Collaborative Corneal Transplantation Studies (CCTS) were designed to evaluate the effect of donor-recipient histocompatibility matching and crossmatching on the survival of corneal transplants in high-risk patients. Corneas were allocated to the 419 patients in the double-masked Antigen Matching Study on the basis of serologically defined HLA-A, -B and HLA-DR antigen match. ABO blood group compatibility was determined but not used for recipient selection. The 37 patients in the Crossmatch Study were randomly assigned to receive a cornea from either a positively or negatively crossmatched donor. All patients received topical steroid therapy according to a standard protocol. Matching for HLA-A, -B and HLA-DR antigens had no effect on overall graft survival, the incidence of irreversible rejection, or the incidence of rejection episodes. At 3 years after surgery, the estimated proportion of eyes with graft failure was 41% for the ABO-incompatible group and 31% for the ABO-compatible group (relative risk, 1.43; 95% confidence interval, 1.00 to 2.06). The estimated proportion of eyes with failure from rejection by 3 years was 30% for the ABO-incompatible group and 16% for the ABO-compatible group (relative risk, 1.98; 95% confidence interval, 1.25 to 3.13). The positive group in the Crossmatch Study had fewer graft failures, rejection failures, and rejection episodes than the negative group; however, these differences were not statistically significant. These studies demonstrate that, for high-risk patients who are immunosuppressed by topical steroid therapy and followed up according to the CCTS protocol: (1) neither HLA-A, -B nor HLA-DR antigen matching substantially reduces the likelihood of corneal graft failure; (2) a positive donor-recipient crossmatch does not dramatically increase the risk of corneal graft failure; and (3) ABO blood group matching, which can be achieved with relatively little effort and expense, may be effective in reducing the risk of graft failure.

To better define the relationship between residual refractive error, uncorrected visual acuity, and pupil diameter, we compared 42 eyes that had an eight-incision radial keratotomy according to the Prospective Evaluation of Radial Keratotomy Study protocol with 42 matched control eyes. The parameters measured were best corrected visual acuity, uncorrected visual acuity, and the change in cycloplegic refraction with enlarging pupil diameter. The best corrected visual acuity was 20/16 in both the radial keratotomy and control groups, but the variability (SD) was higher in the radial keratotomy group. The average uncorrected visual acuity was 0.35 (35%) better in the radial keratotomy group, but the variability was 1.77 times higher. Change in refraction with dilation occurred in 9% of the controls and 36% of the radial keratotomy patients, indicating a significant difference (P = .002). The change in refraction with dilation in the eyes with radial keratotomy was almost equally split between a hyperopic change (17%) and a myopic change (18%), which was much different than in the control eyes, only 2% of which changed in a hyperopic direction and 7% in a myopic direction. The radial keratotomy patients with a myopic change had the best uncorrected visual acuity, indicating that positive spherical aberration yielded the best aspherical surface for uncorrected visual acuity.

Through two prospective studies, we evaluated the use of polyester (Mersilene) sutures in penetrating keratoplasty. Study 1 was a randomized comparison of combined running and interrupted Mersilene and nylon sutures (n = 45). Study 2 was a case series of single running Mersilene with postoperative adjustment of suture tension to manage astigmatism (n = 23). Study 1 demonstrated that Mersilene interrupted sutures were 5.5 times more likely to have handling-related complications compared to nylon (P = 0.01); in addition, they were 3 times as likely to have tissue-related complications as nylon interrupted sutures (P = 0.16). Study 2 demonstrated a complication rate of 69% when Mersilene was used as a single adjustable running suture. At 6 months postoperatively, the median refractive astigmatism for the adjustable cases was 3.37 D (mean, 4.03 +/- 2.37 D). Eyes in Study 2 with significant suture-related complications were 2.85 times more likely to have greater than 4 D of refractive astigmatism than were eyes without suture-related complications. We concluded that Mersilene is an undesirable suture for use in penetrating keratoplasty.