Background: This study was done to identify a group of POAG suspects from the patients attending the O.P.D and to monitor them periodically for a period of one year for detecting early signs of glaucomatous damage of ONH and glaucomatous VFDs.

Materials & Methods: The present study was carried out in Mala Gujri Memorial Medical College, Department of Ophthalmology, Kishanganj from July 15^th, 2016 to June 14^th, 2017. About 50 glaucoma suspects were selected for the study from the patients attending the O.P.D. The selection was made on the basis of findings of gonioscopy, applanation tonometry, direct ophthalmoscopy, slit lamp biomicroscopy, stereoscopic visualization of ONH by +90D lens, automated perimetry by Humphrey Field analyzer (central 30-2 test) and fundus photography.

Results: Of the 100 eyes of 50 cases, suspicious ONH changes were found in 45 eyes of 24 glaucoma suspects, suspicious VFDs in 25 eyes of 18 glaucoma suspects and IOP > 21 mm of Hg/suspicious diurnal variation test &/or suspicious provocative test in 30 eyes of 20 glaucoma suspects. Of the 45 eyes of 24 glaucoma suspects with ONH changes, bilateral ONH changes were seen in 21 cases; rest 3 cases had unilateral ONH changes. Pallor of NRR and diffuse thinning of NRR was found in 44.4%, splinter hemorrhage in l1.1 %, notching of NRR in 11.1% and vertically oval cup in 33.3%. Regarding correlation of asymmetry of C/D with VFDs in glaucoma suspects, of the 50 glaucoma suspects, asymmetry of C/D was found in19 persons, of which asymmetry of 0.1 -0.3 in 12 persons and >0.3 were found in 7 persons. Of the 19 glaucoma suspects with asymmetric C/D, VFDs were seen in 20 eyes of 14 persons (6 persons had bilateral VFDs, 8 persons had unilateral VFDs). VFD percentage of 83.3% was noted in C/D asymmetry between 0.1-0.3 and 142.9% when asymmetry was >0.3. So increasing asymmetry of C/D was related to increasing percentage of VFDs.

Conclusion: The nature of VFDs correlated with ONH changes in established POAG. Localized field defects were seen in early and moderate ONH changes and more generalized field defects were revealed in advanced ONH changes. The nature of VFDs revealed the typical arrangement of nerve fibers in the retina and the optic nerve and the typical pattern of glaucomatous nerve damage. Regarding correlation of C/D with IOP in established POAG, an increase of C/D with increase in IOP was observed.

Keywords: Primary open angle glaucoma, ocular hypertension, glaucoma suspect, optic disc changes, visual field changes.

1. H40-H42 - ICD-10: H40.0, Glaucoma suspect. Ocular hypertension. H40.1, Primary open-angle glaucoma. Available at: https://apps.who.int/classifications/apps/icd/icd10online2003/gh40.htm.
2. Prum BE Jr, Lim MC, Mansberger SL, Stein JD, Moroi SE, Gedde SJ, et al. Primary Open-Angle Glaucoma Suspect Preferred Practice Pattern(®) Guidelines. Ophthalmology. 2016 Jan;123(1):P112-51.
3. Pan Y, Varma R. Natural history of glaucoma. Indian J Ophthalmol. 2011;59 Suppl (Suppl1):S19–S23.
4. Foster PJ. The epidemiology of primary angle closure and associated glaucomatous optic neuropathy. Semin Ophthalmol. 2002;17:50–8.
5. Hodapp E, Parrish RK, Anderson DR. 1st ed. US: St Louis Mosby; 1993. Clinical Decisions in Glaucoma.
6. Ahmad SS. Glaucoma suspects: A practical approach. Taiwan J Ophthalmol. 2018;8(2):74–81.
7. Spaeth GL, Henderer J, Liu C, et al. The disc damage likelihood scale: Reproducibility of a new method of estimating the amount of optic nerve damage caused by glaucoma. Trans Am Ophthalmol Soc 2002; 100:181-185.
8. Drance SM, Flairclough M, Butler, DM, Kottler MS. The importance of disc hemorrhage in the prognosis of chronic open angle glaucoma. Arch Ophthalmol. 1977 Feb;95(2):226-8.
9. Armaly MF. Genetic determination of cup/disc ratio of the optic nerve. Arch Ophthalmol. 1967 Jul;78(1):35-43.
10. Yablonski ME, Zimmerman TJ, Kass MA, Becker B. Prognostic significance of optic disk cupping in ocular hypertensive patients. Am J Ophthalmol. 1980 Apr; 89(4):585-92.
11. Gloster J. Quantitative relationship between cupping of the optic disc and visual field loss in chronic simple glaucoma. Br J Ophthalmol. 1978 Oct;62(10):665-9.
12. Susanna R, Drance SM. Use of discriminant analysis I. Prediction of visual field defects from features of the glaucoma disc. Arch Ophthalmol. 1978 Sep;96(9):1568-70.
13. Katz J, Tielsch JM, Quigley HA, Sommer A. Automated perimetry detects visual field loss before manual Goldmann perimetry. Ophthalmology. 1995 Jan;102(1):21-6.
14. Quigley HA. Glaucoma's optic nerve damage: changing clinical perspectives. Ann Ophthalmol. 1982 Jul;14(7):611-2.
15. Garway-Heath DF, Poinoosawmy D, Fitzke FW, Hitchings RA. Mapping the visual field to the optic disc in normal tension glaucoma eyes. Ophthalmology. 2000 Oct;107(10):1809-15.
16. Schuman JS, Pedut-Kloizman T, Hertzmark E, Hee MR, Wilkins JR, Coker JG, Puliafito CA, Fujimoto JG, Swanson EA. Reproducibility of nerve fiber layer thickness measurements using optical coherence tomography. Ophthalmology. 1996 Nov;103(11):1889–1898.
17. Tanito M, Itai N, Dong J, Ohira A, Chihara E. Correlation between intraocular pressure level and optic disc changes in high-tension glaucoma suspects. Ophthalmology. 2003 May;110(5):915-21.
18. Pohjanpelto PE, Palva J. Ocular hypertension and glaucomatous optic nerve damage. Acta Ophthalmol (Copenh). 1974;52(2):194-200.
19. Tielsch JM, Sommer A, Katz J, Royall RM, Quigley HA, Javitt J. Racial variations in the prevalence of primary open-angle glaucoma. The Baltimore Eye Survey. JAMA. 1991 Jul 17;266(3):369-74.
20. Gordon MO1, Beiser JA, Brandt JD, Heuer DK, Higginbotham EJ, Johnson CA, et al. The Ocular Hypertension Treatment Study: baseline factors that predict the onset of primary open-angle glaucoma. Arch Ophthalmol. 2002 Jun;120(6):714-20; discussion 829-30.
21. Leske MC, Connell AM, Wu SY, Hyman LG, Schachat AP. Risk factors for open-angle glaucoma. The Barbados Eye Study. Arch Ophthalmol. 1995 Jul;113(7):918-24.
22. Mitchell P, Hourihan F, Sandbach J, Wang JJ. The relationship between glaucoma and myopia: the Blue Mountains Eye Study. Ophthalmology. 1999 Oct;106(10):2010-5.
23. The Advanced Glaucoma Intervention Study (AGIS): 3. Baseline characteristics of black and white patients. Ophthalmology. 1998 Jul;105(7):1137-45.
24. Bankes JL, Perkins ES, Tsolakis S, Wright JE. Bedford glaucoma survey. Br Med J. 1968;1:791–796.
25. Sommer A, Tielsch JM, Katz J, et al. Relationship between intraocular pressure and primary open angle glaucoma among white and black Americans. The Baltimore Eye Survey. Arch Ophthalmol. 1991 Aug. 109(8):1090-5.
26. Zhou M, Wang W, Huang W, Zhang X. Diabetes mellitus as a risk factor for open-angle glaucoma: a systematic review and meta-analysis. PLoS One. 2014 Aug 19;9(8):e102972.

Dr Dinesh Kumar Bhagat

Assistant Professor, Department of Ophthalmology, Mata Gujri Memorial Medical College & Lions Seva Kendra Hospital, Kishanganj, Bihar- 855107, India