Abstract
Purpose:
The Glaucoma Stereo Analysis Study (GSAS) is a multicenter, collaborative study to explore characteristics of glaucomatous optic disc morphology by using a stereo fundus camera. Optic disc parameters obtained from GSAS were compared between eyes with different optic disc appearances.
Methods:
This five-center, retrospective study enrolled study criteria-eligible 187 primary open angle glaucoma eyes from 187 subjects (100 males, and 87 females, mean ± SD age of 62 ± 9 years). Optic disc recorded by stereo fundus camera (Nonmyd WX3D, Kowa Company Ltd., Japan) were three-dimensionally analyzed by newly developed software to calculate various optic disc parameters. Based on the proposal by Nicolela and Drance (Ophthalmology 103(4), 640-9, 1996), three independent graders classified subjects’ optic disc appearance into 4 subclasses [focal ischemic, FI (n=34); myopic glaucomatous, MY (n=96); senile sclerotic, SS (n=19); and generalized enlargement, GE (n=38)]. Baseline characteristics and optic disc parameters were compared among 4 subclasses by un-paired t-tests. To correct multi-group comparisons, based on Bonferroni’s approach, p value of 0.0083 was considered to be statistically significant.
Results:
Compared to other subclasses, younger age, lower refractive errors, smaller disc area, larger height variation contour, larger rim volume, and larger horizontal disc tilt angle in MY, lower refractive errors in SS, deeper cup depth and larger cup volume in GE were found. By all 39 optic disc parameters-substituted partition analyses, 3 parameters including horizontal disc tilt angle, mean cup depth, and rim volume were found to be significant; by using these 3 parameters, area under the receiver operating characteristic curves for discrimination of 4 subclasses were calculated to be 0.74, 0.86, 0.81, and 0.87 for FI, MY, SS, and GE, respectively.
Conclusions:
The results suggest the possible discrimination of different optic disc appearances by using parameters obtained by stereo fundus camera analyses.
Keywords: 627 optic disc •
550 imaging/image analysis: clinical •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques