Faculty Bibliography

PURPOSE: Contact transscleral neodymium:yttrium-aluminum-garnet (Nd:YAG) laser cyclophotocoagulation (CYC) is a treatment option for advanced glaucoma refractory to alternative treatments. This study determined the long-term efficacy and risks of contact transscleral Nd:YAG laser CYC. DESIGN: A prospective study was performed with patients with advanced, uncontrolled glaucoma who received CYC from 1988 through 1989. PARTICIPANTS: Records for 68 eyes of 64 patients were obtained and reviewed for the 10-year follow-up. METHODS: A transscleral continuous-wave Nd:YAG laser was used for photocoagulation of the ciliary body. MAIN OUTCOME MEASURES: Intraocular pressure (IOP), visual acuity, and second intervention. Failure was defined as the need for second intervention, IOP of more than 25 mmHg, or IOP of less than 3 mmHg. RESULTS: The mean follow-up period was 5.85+/-4.0 years (range, 0.1-10 years). The mean preoperative IOP of 36.3+/-10.1 mmHg decreased to 22.6+/-11.3 mmHg at 1 year of follow-up (P<0.001). The mean postoperative IOP at 5 years was 21.8+/-13.3 mmHg (P<0.001) and was 18.9+/-12.2 mmHg at 10 years of follow-up (P<0.001). A second intervention after CYC was required in 30 eyes (44.1%). Six eyes (8.8%) with initial visual acuity of counting fingers or worse progressed to no light perception, and 5 of 8 eyes (62.5%) with visual acuity better than 20/200 lost 2 or more Snellen lines. Hypotony developed in 3 eyes (4.4%). Overall, the failure rate by 10 years of follow-up was 51.5% (35/68 eyes). CONCLUSIONS: Cyclophotocoagulation resulted in a significant reduction of IOP after surgery at 1, 5, and 10 years of follow-up; however, 51.5% of eyes failed by the end of 10 years, with most failures occurring within the first year (40%). Although CYC provides a useful method to lower IOP significantly, this study suggests that its success in controlling IOP is tempered by its failure rate and risk of complications, including visual loss, phthisis, and loss of light perception

PURPOSE: To investigate the structure-function relationship between optical coherence tomography (OCT) macular retinal and peripapillary nerve fiber layer (NFL) thickness and automated visual field (VF) findings. DESIGN: Cross-sectional observational study. METHODS: Retrospective institutional study where 150 consecutive eyes (101 subjects) from a glaucoma service were included. All the participants had full ophthalmic evaluation, VF testing and prototype OCT scanning at the same visit. Orthogonal OCT macular analysis was obtained to maximize the sampling of the area of interest. Pearson age-adjusted correlation was determined between macular retinal thickness and peripapillary NFL thickness. Area under the receiver operator characteristics (AROC) curves for the association between macular retinal thickness and peripapillary NFL thickness and VF findings were calculated in a subgroup of eyes without VF defect and eyes with VF defect confined to one hemifield. RESULTS: The correlation between macular retinal and peripapillary NFL measurements ranged between r =.27 to.54 for quadrants,.44 to.55 for hemiretina, and.52 for the overall mean. Areas under the receiver operator characteristics for macular thickness were higher in areas corresponding to the VF defect location than the noncorresponding locations. Areas under the receiver operator characteristics for peripapillary NFL thickness were higher than for the macular retinal thickness. Including both macular retinal thickness and peripapillary NFL thickness measurements in the logistic regression model yielded AROCs (range:.69 -.77) similar to those found for the peripapillary NFL alone. CONCLUSION: Macular retinal thickness, as measured by OCT, was capable of detecting glaucomatous damage and corresponded with peripapillary NFL thickness; however, peripapillary NFL thickness had higher sensitivity and specificity for the detection of VF abnormalities.

PURPOSE: The measurement reproducibility of the third generation of commercial optical coherence tomography, OCT-3 (StratusOCT, software ver. A2, Carl Zeiss Meditec Inc., Dublin, CA) was investigated. The nerve fiber layer (NFL) thickness, macula thickness map, and optic nerve head (ONH) parameters in normal eyes were studied. METHODS: Ten normal subjects were imaged six times (three before and three after dilation) per day, and the series was repeated on three different days. The order of the scans before pupil dilation was randomized in each of the 3 days of scanning. After pupil dilation, the scans were also randomized in each of the 3 days of scanning. Each series was performed separately for standard-density (128 A-scans per macular and ONH image and 256 A-scans per NFL image) and high-density (512 A-scans per image for all three scan types) scanning. RESULTS: The mean macular thickness was 235 +/- 9.8 micro m. A-scan density (or image acquisition speed) had a statistically significant effect (P < 0.05) on the reproducibility of the mean macular thickness, macular volume, and a few sectors of the macular map. No significant dilation effect was found for any of the macular parameters. The best intraclass correlation coefficient (ICC; 94%) for macular scans was found for dilated high-density scanning, with an intervisit SD of 2.4 micro m and an intravisit SD of 2.2 micro m. The mean NFL thickness for standard scanning was 98 +/- 9 micro m. NFL reproducibility showed mixed results and had interactions between scan density and dilation for some parameters. For most of the NFL parameters, reproducibility was better with dilated standard-density scanning. The mean NFL thickness ICC for dilated standard scanning was 79%, with an intervisit SD of 2.5 micro m and an intravisit SD of 1.6 micro m. For the ONH analysis, the reproducibility was better for dilated standard-density scanning for almost all the parameters, except for disc area, horizontal integrated rim volume, and vertical integrated rim area, which were better before dilation. The best reproducibility was found for cup-to-disc ratio (ICC = 97%, with intervisit SD of 0.04 micro m and intravisit SD of 0.02 micro m). CONCLUSIONS: StratusOCT demonstrated reproducible measurements of NFL thickness, macular thickness, and optic nerve head parameters. The best reproducibility was found for dilated standard scanning for NFL and ONH parameters and for dilated high-density scanning for macular parameters.

Structural assessment using the imaging technologies discussed herein provides reproducible quantitative measurements of posterior segment ocular structures. These measurements have been found to provide useful data for glaucoma detection in various regions of the posterior segment. Further studies are needed to evaluate the utility of these technologies for pre-perimetric glaucoma detection and for monitoring glaucoma progression over an extended period.