Publication:

Effect of spherical rigid gas permeable lens on correction of corneal astigmatism

Background Objectives were to study an effect of spherical RGP (rigid gas permeable) contact lens in correcting high corneal astigmatism more than 3 diopter.

Methods Total 48 eyes with corneal astigmatism greater than 3.00 diopter were included in study. At the first visit, routine preliminary examination, parameter assessment and subjective refraction has been carried out followed by patient counselling for RGP lens wear. Based on the corneal parameters considering keratometry as well as corneal topography, RGP lens trial was done. Post adaptation period, lens fitting analysis was done by understanding Fluorescein pattern with slit lamp and over refraction was done. Final lens has been ordered on this basis with understanding of tear lens formed, lens performance on cornea and edge width minimal of 0.80 mm to 1.00 mm. Patients were assessed at an interval of every two months from a date of lens dispensing.

Results The spherical RGP lens did correct the corneal astigmatism of more than 3D by formation of tear lens between cornea and lens. Vision improved by 2 to 3 lines compared to the spectacle correction without compromising corneal integrity at the central or peripheral cornea. Keratoconic eye showed significant vision improvement without the use of toric lens.

Conclusions Astigmatic eyes showed significant improvement in acuity with spherical RGP lens without compromising corneal integrity.