The GILS (Glaucoma Imaging Longitudinal Study): Baseline Characteristics of Participants

Abstract

Abstract: : Purpose: To describe participants in the GIL (Glaucoma Imaging Longitudinal) Study, a study to evaluate the relative utility of imaging the optic disc and macula for predicting progression of glaucomatous visual field defects. Methods: Patients with primary open-angle glaucoma, confirmed by at least 2 visual fields with glaucoma hemifield test "Outside normal limits" or MD <5% or PSD <5%, with corroborating optic disc changes, were recruited into the GILS. Patients are followed at 6-month intervals with visual field (VF) testing (Humphrey II perimeter, 24-2 (SITA Fast), Zeiss Humphrey, Dublin, CA, USA), Heidelberg Retinal Tomograph (HRT II, Heidelberg Engineering GmbH, Heidelberg, Germany) scanning of the optic disc, and Retinal Thickness Analyzer (RTA, Talia Technologies, Ltd., Neve Ilan, Israel) measurement of the macular area. Stereo optic disc photos are obtained at baseline and yearly thereafter. Results: A total of 631 patients were eligible for the study; 202 (32%) were enrolled at baseline. Age of participants ranges from 35 to 91 y (mean, 69 y); 51% are female. 19% are African-American, 76% are of European descent, and 5% are Asian, Hispanic, or of other ethnicity. Mean baseline VF characteristics: MD: -9.6 dB (range, -28.1 - 0.8); PSD: 7.7 dB (range 0 - 15.3); 88.3% with GHT outside normal limits. Mean HRT cup/disc ratio was 0.48 (range, 0.003 - 0.93); Participants are of similar age 69.2 y (range, 34.7 - 90.7 y) and gender (56% are female) to nonparticipants; however, African-American patients are slightly under-represented. Conclusions: The GILS includes glaucoma patients that have characteristics that are reasonably representive of the general US population of persons with moderate to severe glaucoma. This group is being followed for at least 5 years to determine optic disc and macular thickness characteristics that can predict further VF loss.

Keywords: clinical (human) or epidemiologic studies: ris • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • ganglion cells