The Effect of ChromaGen Contact Lenses on Corneal Clarity: A Corneal Densitometry

The purpose of this study is to investigate the effect of ChromaGen contact lens (CCL) on corneal clarity, expressed through the measurement of corneal densitometry (CD) values.

This study included 22 eyes of 22 patients with congenital red-green color vision deficiency who were admitted to our clinic for the CCL trial. After a detailed ophthalmological examination and CD measurement with Pentacam HR (Oculus Optikgerate GmbH, Wetzlar, Germany), the most appropriate CCLs were defined through pseudoisochromatic plates and inserted for 2 h. The CD measurement was repeated after the removal of the CCL. Comparison was made of CD values before and after the insertion of the most appropriate CCL. The after-CCL/before-CCL ratio was calculated, and the effect of CCL type on this ratio was investigated.

The after-CCL values were higher in the anterior, central, posterior, and total thickness of the 0-2 mm concentric zone (p=0.044, p=0.040, p=0.021, and p=0.032, respectively) when compared to the before-CCL values. There was no statistically significant difference between before-CCL and after-CCL values in any layer of the 2-6, 6-10, and 10-12 mm concentric zones (p>0.05, for all). After-CCL/before-CCL ratios were similar in the Magenta2 (M2), Magenta3 (M3), and Violet3 (V3) types of CCLs (p>0.017).

Usage for 2 h of CCL was observed to increase CD values in all layers of the 0-2 mm concentric zone irrespective of the type of CCL. Further studies with longer follow-up are required to determine the long-term effects and detect differing effects of CCL with different base curves.