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Validation of formula‐predicted glaucomatous optic disc appearances: the Glaucoma Stereo Analysis Study
Author(s) -
Tanito Masaki,
Nitta Koji,
Katai Maki,
Kitaoka Yasushi,
Yokoyama Yu,
Omodaka Kazuko,
Naito Tomoko,
Yamashita Takehiro,
Mizoue Shiro,
Iwase Aiko,
Nakazawa Toru
Publication year - 2019
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.13816
Subject(s) - optic disc , glaucoma , optic cup (embryology) , ophthalmology , fundus (uterus) , optic disk , medicine , optic nerve , gonioscopy , intraocular pressure , tilt (camera) , optometry , mathematics , geometry , chemistry , biochemistry , gene , eye development , phenotype
Abstract Aims The Glaucoma Stereo Analysis Study ( GSAS ) is a multicentre collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera. Using the GSAS dataset, we previously established a formula for predicting different appearances of glaucomatous optic discs, although the formula lacked validation in an independent dataset. In this study, the formula was validated in another testing dataset. Subjects and Methods Testing dataset contained three‐dimensionally analysed optic disc topographic parameters from 93 eyes with primary open‐angle glaucoma; six topographic parameters (temporal and nasal rim‐disc ratios, mean cup depth, height variation contour, disc tilt angle and rim decentring absolute value) were used for predicting different appearances of glaucomatous optic discs. The agreement between grader‐classified optic disc types, that is, focal ischemic ( FI ), generalized enlargement, myopic glaucomatous ( MY ), and senile sclerotic ( SS ) and formula‐predicted optic disc types, that is, pFI , pGE , pMY and pSS , were assessed. Results Based on this formula, the eyes were classified with pFI (21 eyes, 22.6%), pGE (27 eyes, 29.0%), pMY (26 eyes, 28.0%) and pSS (19 eyes, 20.4%) when the top predictive element based on the formula was considered as the optic disc appearance in each eye. The six topographic parameters used in the formula differed significantly among the four predicted optic disc types. Substantial agreement ( κ = 0.7496) was seen for the top two predictive elements based on the formula that agreed with the graders’ classification in 76 (81.7%) eyes. Among the four optic disc types, the levels of agreement were relatively lower in the SS type ( κ = 0.3863–0.5729) compared with the other three optic disc types ( κ = 0.7898–0.8956) even though the unclassifiable and mixed optic disc types were excluded from the testing dataset. Conclusion The GSAS classification formula can predict and quantify each component of different optic disc appearances in each eye and provide a novel parameter to describe glaucomatous optic disc characteristics.