Original Research Article DOI: 10.18231/2395-1451.2017.0101 Indian Journal of Clinical and Experimental Ophthalmology, October-December, 2017; 3(4): 412-415 412 Evaluation of visual acuity and contrast sensitivity in patients of moderate to advance glaucoma with visual disability attending the low vision clinic Praveen K Chaturvedi 1,* , Prashant Bhushan 2 , Rajendra Prakash Maurya 3 , Mahendra Kumar Singh 4 , Virendra Pratap Singh 5 1 Senior resident, 2 Associate professor, 3 Assistant professor, 4 Professor and Head, 5 Professor, Dept. of Ophthalmology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India *Corresponding Author Email: drpcunb10@gmail.com Abstract Purpose: Aims of this study is to characterise the visual disability of patients of glaucoma in terms of LogMAR visual acuity, contrast sensitivity, optic disc changes and intraocular pressure. Materials & Methods: A total of 30 eyes with the glaucomatous damage having low vision (WHO Criteria) with predefined inclusion and exclusion criteria were included as cases and 40 eyes with normal or near normal visual status correctable by refraction were included as control in the study. The visual acuity and contrast sensitivity were noted and analysed. Results: The best corrected visual acuity (BCVA) of all eyes in control group is less than 0.5 LogMAR units. Among cases, 25(83.3%) eyes have BCVA in the range of 0.5 to 1.0 LogMAR units and 5(16.7%) eyes have BCVA in the range of 1.0 to 1.3 LogMAR units, satisfying the inclusion criteria significantly (p value < 0.001). In case group, direct correlation of association is observed between uncorrected visual acuity and best corrected visual acuity (r = 0.8), near visual acuity (r = 0.73), best corrected near visual acuity (r = 0.48) and cup to disc ratio (r = 0.65) and inverse correlation of association with contrast sensitivity (r = - 0.39) and intra ocular pressure (r = -0.51) which are statistically significant (p value <0.05). Conclusions: In patients of glaucoma with visual impairment, there is a negative correlation between contrast sensitivity and visual acuity in logMAR units. Keywords: Glaucoma, logMAR visual acuity, Contrast sensitivity, Visual impairment. Introduction Glaucoma is a progressive optic neuropathy with characteristic changes in the optic nerve head and corresponding visual field loss. Currently, glaucoma accounts for 12% of all global blindness with 4.5 million people affected worldwide. (1) In order to detect early glaucomatous changes, clinicians need to identify these changes and distinguish them from variations of normal. Rate of disease progression is one of the most important factors determining the risk of visual disability or blindness in glaucoma. (2) Defining glaucoma precisely is quite difficult as it encompasses a diverse group of disorders. All forms of the diseases have in common a potentially progressive and characteristic optic neuropathy which is associated with visual field loss as damage progresses, and in which intraocular pressure is usually a key modifying factor. (1) In purview of the functional complaints made by glaucoma patients, the manifestation of their loss of contrast sensitivity affected by the disease process correlated to a greater extent than their high contrast visual acuity. Therefore, it is possible to detect glaucoma with various contrast sensitivity tests prior to visual acuity changes and even visual field damages. (2,3,4) In order to quantitate this loss in contrast sensitivity related to their glaucoma damage, a preliminary study was done with contrast sensitivity measurements using the Pelli- Robson chart (5) and relating these findings to visual acuity performance on LogMAR visual acuity chart. Materials & Methods The study was approved by the institutional review board and informed consent was obtained from each individuals. The study followed the tenets of the declaration of Helsinki. A total of 30 eyes with the diagnosis of moderate and advanced glaucomatous damage having low vision by WHO Criteria with predefined inclusion criteria of patient giving consent and having moderate and advance glaucoma with visual acuity less than 6/18 to hand movement were included as cases. Whereas, unwilling patients and patients with any other associated ocular disease e.g. Uveitis, corneal disorders etc. or systemic disease e.g. Thyroid disorders etc. were excluded from the case group in this study. Among control group 40 eyes with normal or near normal visual status correctable by refraction were included in the study. Patients underwent detailed ophthalmological examinations including tonometry, visual acuity (LogMAR), contrast sensitivity (Pelli-Robson chart), slit lamp examination and slit lamp biomicroscopy with 78D lens, indirect ophthalmoscopy and Humphery field analyser for quantifying and diagnosing as moderate and advanced glaucoma. The visual acuity of the patients was measured using the Bailey–Lovie logMAR visual acuity chart for distance and Bailey–Lovie word reading charts for near. The contrast sensitivity was measured using the standardized illuminated Pelli-Robson chart.