Original Research Article DOI: 10.18231/2395-1451.2017.0003 Indian Journal of Clinical and Experimental Ophthalmology, January-March,2017;3(1): 3-10 3 Study of correlation of cup disc ratio with visual field loss in primary open angle glaucoma Pankaj Soni 1,* , Ashwani Srivastava 2 , Akash Srivastava 3 , Deepti Yadav 4 1 Assistant Professor, 2,3,4 Junior Resident, B.R.D. Medical College, Uttar Pradesh *Corresponding Author: Email: drpankajpbh@gmail.com 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 Introduction Chronic Open Angle Glaucoma (COAG) may be defined as a chronic progressive optic neuropathy accompanied by characteristic visual field defects and disc changes, with intraocular pressure being the commonest risk factor. By definition there is no apparent obstruction of the trabecular meshwork by structures such as the iris on gonioscopic examination. Glaucoma is the leading cause of irreversible blindness in the world. World Health Organization statistics, published in 1995, indicate that glaucoma accounts for blindness in 5.1 million persons, or 13.5% of Global Blindness. According to world health organization Glaucoma is the second leading cause of blindness in the world. The common denominator of all the glaucomas is characteristic Optic Neuropathy, which derives from various risk factors including increased intraocular pressure (IOP). Although elevated intraocular pressure is the most frequent causative risk factor for glaucomatous optic neuropathy, it is not the only factor. Once the blindness of glaucoma has occurred, there is no known treatment that will restore the lost vision. However, in nearly all the cases, blindness from glaucoma is preventable. This prevention requires early detection and proper treatment. Detection depends on the ability to recognize the early clinical manifestations of the various glaucomas. The most important component of the constellation of signs and symptoms of glaucoma is the characteristic visual field loss along with the typical glaucomatous optic neuropathy which presents as an asymmetric loss of the neuroretinal rim of the optic nerve head, widening of the cup, baring of the lamina cribrosa, pallor of the neuroretinal rim, peripapillary atrophy, and later cavernous atrophy of the optic nerve head. On Direct Ophthalmoscopy, the above signs can be elucidated. Examination by Direct Ophthalmoscopy under a red-free light also reveals the slit or later the wedge shaped defects in the nerve fiber layer. Glaucomatous optic atrophy Focal Atrophy: Selective loss of neural rim tissue in glaucoma occurs primarily in the inferotemporal region of the optic nerve head and, less commonly in the superotemporal sector leading to enlargement of cup in