Evaluation of the different methods of optic disc examination in glaucomatous patients

Background Glaucoma is a leading cause of blindness worldwide. Many patients discover glaucoma accidentally during regular checkups. Purpose To evaluate the agreement using slit lamp biomicroscopy, stereoscopic fundus photography, and optical coherence tomography (OCT) in the evaluation of the optic disc area, the cup area, and the vertical cup disc ratio (VCDR) in glaucomatous patients. Patients and methods This cross-sectional observational study includes 28 eyes of glaucomatous patients. All patients underwent slit lamp biomicroscopy using a +90 D lens, stereoscopic fundus photography using a computerized program to measure the optic disc parameters, and OCT for optic disc evaluation. Three examiners did the analysis. Results Comparing results obtained on stereoscopic fundus photography and OCT, examiner one reported moderate reliability regarding disc area, cup area, and the VCDR with an intraclass coefficient (ICC) of 0.67, 0.67, and 0.50 and P values of 0.68, 0.61, and 0.01, respectively. Examiner two reported moderate reliability regarding disc area, cup area, and VCDR with an ICC of 0.66, 0.63, and 0.54 and P values of 0.16, 0.69, and 0.03, respectively. Examiner three reported moderate reliability regarding disc area and VCDR with an ICC of 0.65, 0.71, and P values of 0.69 and 0.07, respectively. A good reliability for the cup area was reported with an ICC of 0.82 and a P value of 0.02. The slit lamp and stereoscopic fundus photos showed moderate reliability compared with fundus photography values. Conclusion There is an agreement between values obtained by slit lamp biomicroscopy, stereoscopic fundus photography, and OCT.