Indian Journal of Clinical and Experimental Ophthalmology


Study of correlation of cup disc ratio with visual field loss in primary open angle glaucoma


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Author Details: Pankaj Soni, Ashwani Srivastava, Akash Srivastava, Deepti Yadav

Volume : 3

Issue : 1

Online ISSN : 2395-1451

Print ISSN : 2395-1443

Article First Page : 3

Article End Page : 10


Abstract

Objective: To correlate the cup/disc ratio with visual field defect in primary open angle glaucoma patient using magnified photograph of optic disc and Humphrey field analyzer. Method: Cross sectional study includes 114 eyes of 60 patients suffering from primary open angle glaucoma. All patients were 40 years age having IOP 21 mmHg and gonioscopically open angle of anterior chamber. The things assessed includes IOP, angle of anterior chamber, optic disc and visual field.
Results: Total 114 eyes of 60 patients with primary open angle glaucoma included in study. Mean age of patient in our study was 58.7±10.26 year. Out of 60 patients, 31 (51.66%) were male and 29 (48.33%) were female. 12 eyes (10.52%) had IOP in the range of 21-24 mmHg, 52 eyes (45.61%) had IOP in the range of 25-29 mmHg, 48 eyes (42.10%) had IOP in the range of 30-34 while only 2 eyes (1.75%) had IOP > 35 mmHg. Mean IOP of 114 eyes was 27.9±3.23 mmHg. 32 patient (28.07%) had C:D ratio of 0.6 whereas 30 patient (26.31s%) had C:D ratio 0.7. Mean C:D ratio of POAG was 0.64±0.07. Considering other parameter of the optic nerve head it was seen that Bayonetting sign was present in 60 eyes. Meanwhile baring of vessels was seen in 46 eyes. Laminar dot sign, on the other hand was seen in 72 eyes. Beta zone peripapillary atrophy was seen in 78 eyes. Another important parameter of the optic disc is notching. In 53 eyes notching was seen. Out of these, 35 eyes show superior notching, of which 33 eyes (94.3%) correlated with inferior field defects. 18 eyes show inferior notching, and all of them showed superior field defect. Inferior neuroretinal thinning is found in 55 eyes, out of which 50 eyes (90.9%) had correlating visual field defect while 32 eyes (86.5%) with superior neuroretinal thinning correlate visual field defect. Maximum number of eyes show superior zone defect i.e. 54 eyes (47.36%) followed by inferior zone defect in 25 eyes (22.0%). The least common visual field defect in our study is baring of blind spot in 3 eyes (3.0%). Finally, the patients were divided into 2 group depending on their cup disc ratio, and their association with the field defects was evaluated. Group 1- patients with c:d ratio < 0.7;Group 2- patients with c:d ratio 0.7. The pattern defects signifying the localized defects were then compared between the two group. The average pattern defect in group- 1 was found to be 6.16 db, while the average pattern deviation in group- 2 was 9.62 db. The association of c:d ratio 0.7 with PD was seen to be significant with a p <0.001. Conclusions: This was a cross sectional study done over a period of 1 year to correlate the optic disc changes with the visual field defects by using optic disc evaluation and Humphrey visual field analyzer done. The correlation between cup disc ratio and intra.

Keywords:
Cup disc ratio, Gonioscopy, Neuroretinal rim, Bayonetting sign, Peri papillary atrophy