Assessing glaucoma deterioration using Spaeth/Richman contrast sensitivity test.

Ichhpujani, Parul; Singh, Tanu; Thakur, Sahil; Singh, Rohan Bir; Kumar, Suresh

Purpose To assess changes in the central and peripheral contrast sensitivity in severe primary open-angle glaucoma (POAG) patients using a computer-based Spaeth/Richman contrast sensitivity test (SPARCS) over a period of 24 months. Methods Our pilot, observational study included 15 patients (30 eyes) with severe POAG. Visual acuity, intraocular pressure, number of anti-glaucoma drugs, visual fields, and SPARCS score were recorded at first visit and at 12 and 24 months. Results We observed changes in mean deviation (MD) from -19.37 ± 5.04 to -20.63 ± 4.07, mean pattern standard deviation (PSD) from 11.49 ± 2.61 to 11.35 ± 2.01, and mean SPARCS score from 54.97 ± 15.66 to 53.50 ± 16.42. We found no statistically significant difference between visual field parameters and SPARCS scores associated with the number or type of prescribed anti-glaucoma drugs. Spearman's correlation coefficient of SPARCS at baseline (SPARCS1) versus MD at baseline (MD1) was 0.274 (p = 0.142) and SPARCS1 versus PSD at baseline (PSD1) was -0.163 (p = 0.389). The correlation coefficient between SPARCS at 12 months (SPARCS2) versus MD (MD2) at the same time point was computed to be 0.391 (p = 0.03), whereas SPARCS2 versus PSD at 12 months was -0.212 (p = 0.262). Similarly, we found the coefficient to be 0.336 (p = 0.069) for SPARCS3 (SPARCS at 24 months) versus MD3 (MD at 24 months) and -0.242 (p = 0.197) for SPARCS3 versus PSD3 (PSD at 24 months). Correlation coefficients between SPARCS1/2, SPARCS1/3, MD1/2, MD1/3 PSD1/2, and PSD1/3 were 0.856, 0.865, 0.748, 0.722, 0.497, and 0.562, respectively (p < 0.001). MD changed by 9.46% ± 12.73%, PSD by 0.64% ± 14.03%, and average SPARCS by 3.31% ± 12.73% over 24 months. Conclusion The data from our study indicate the utilitarian application of SPARCS, an inexpensive and readily available tool for monitoring functional deterioration in cases with advanced glaucomatous damage, especially in resource-poor settings. Furthermore, it is a useful and reliable alternative to the imaging modalities where retinal nerve fiber layer measurement can be erroneous in advanced cases secondary to the floor effect.