Agreement of measurement of parapapillary atrophy with confocal scanning laser ophthalmoscopy and planimetry of photographs

Purpose: To evaluate whether parapapillary atrophy can be measured interact ively using confocal scanning laser ophthalmoscopy. Methods: For 36 patients with open-angle glaucoma or suspected of having gl aucoma, confocal scanning laser ophthalmoscopy of the optic nerve head was performed using the Heidelberg Retina Tomograph (HRT; Heidelberg Engineerin g, Heidelberg, Germany). Alpha and beta zones of parapapillary atrophy were plotted independently by two examiners on HRT images before and after revi ewing optic disc photographs. These data were compared with planimetric mea surements obtained from analyzing the disc photographs. Results: Before viewing the disc photographs, assessment using the HRT imag es correlated better with the beta zone than alpha zone planimetric measure ments. If the HRT images were evaluated while simultaneously viewing disc p hotographs, correlation coefficients increased for both examiners 1 and 2. Interobserver and intraobserver reliability were 0.431 and 0.802, respectiv ely, for alpha zone, and 0.882 and 0.948, respectively, for beta zone. Conclusion: Parapapillary atrophy can be estimated with confocal scanning l aser ophthalmoscopy. Correlation with planimetric measurements is best if c onventional optic disc photographs are simultaneously viewed. Intraobserver and interobserver reliability are higher for beta zone than for alpha zone .