Cagri Ilhan1, Mehmet A Sekeroglu2, Sibel Doguizi2, Pelin Yilmazbas2. 1. Department of Ophthalmology, Hatay State Hospital, Antakya, Turkey. 2. Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.
Abstract
BACKGROUND: To evaluate the effects of the ChromaGen contact lens (CCL) on best-corrected visual acuity, contrast sensitivity and pseudoisochromatic test plate performance in patients with congenital colour vision deficiency (CVD). METHODS: CCLs were inserted into 50 eyes of 25 patients with congenital red-green CVD. The patients were tested with the Ishihara and Hardy-Rand-Rittler test plates before and after the insertion of Magenta 2, Magenta 3, and Violet 3 CCLs. The patients' mean numbers of recognised symbols were calculated and the most appropriate CCL was determined for each eye. The best-corrected visual acuity for both far and near vision and contrast sensitivity were evaluated before and after the insertion of the appropriate CCLs, and the results were compared. RESULTS: The mean age of the patients was 26.56 ± 10.30 years. While all CCLs increased the mean numbers of recognised symbols on the Ishihara (p < 0.001 for all), Magenta 3 was observed to be the most useful CCL. On the other hand, while all CCLs increased the mean numbers of recognised symbols on Hardy-Rand-Rittler (p < 0.001 for all), Magenta 2 and Magenta 3 were detected as the most useful CCLs. After insertion of the most appropriate CCL for each eye, the mean best-corrected visual acuity for both far and near vision were decreased (p < 0.001 for both). Statistically significant alterations were also detected at some spatial frequencies of contrast sensitivity measurements. CONCLUSION: CCLs decrease the far and near best-corrected visual acuity, and static and dynamic contrast sensitivity at some spatial frequencies, and invalidate the pass criteria of pseudoisochromatic test plates by increasing the number of recognised symbols.
BACKGROUND: To evaluate the effects of the ChromaGen contact lens (CCL) on best-corrected visual acuity, contrast sensitivity and pseudoisochromatic test plate performance in patients with congenital colour vision deficiency (CVD). METHODS: CCLs were inserted into 50 eyes of 25 patients with congenital red-green CVD. The patients were tested with the Ishihara and Hardy-Rand-Rittler test plates before and after the insertion of Magenta 2, Magenta 3, and Violet 3 CCLs. The patients' mean numbers of recognised symbols were calculated and the most appropriate CCL was determined for each eye. The best-corrected visual acuity for both far and near vision and contrast sensitivity were evaluated before and after the insertion of the appropriate CCLs, and the results were compared. RESULTS: The mean age of the patients was 26.56 ± 10.30 years. While all CCLs increased the mean numbers of recognised symbols on the Ishihara (p < 0.001 for all), Magenta 3 was observed to be the most useful CCL. On the other hand, while all CCLs increased the mean numbers of recognised symbols on Hardy-Rand-Rittler (p < 0.001 for all), Magenta 2 and Magenta 3 were detected as the most useful CCLs. After insertion of the most appropriate CCL for each eye, the mean best-corrected visual acuity for both far and near vision were decreased (p < 0.001 for both). Statistically significant alterations were also detected at some spatial frequencies of contrast sensitivity measurements. CONCLUSION: CCLs decrease the far and near best-corrected visual acuity, and static and dynamic contrast sensitivity at some spatial frequencies, and invalidate the pass criteria of pseudoisochromatic test plates by increasing the number of recognised symbols.