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) MD at baseline (MD1) was 0.274 ( = 0.142) and SPARCS1 PSD at baseline (PSD1) was -0.163 ( = 0.389). The correlation coefficient between SPARCS at 12 months (SPARCS2) MD (MD2) at the same time point was computed to be 0.391 ( = 0.03), whereas SPARCS2 PSD at 12 months was -0.212 ( = 0.262). Similarly, we found the coefficient to be 0.336 ( = 0.069) for SPARCS3 (SPARCS at 24 months) MD3 (MD at 24 months) and 0.242 ( = 0.197) for SPARCS3 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 ( < 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.