Author/Authors :
Hasani, Mohammadali Noor Research Center for Ophthalmic Epidemiology - Noor Eye Hospital, Tehran, Iran , Hashemi, Hassan Noor Research Center for Ophthalmic Epidemiology - Noor Eye Hospital, Tehran, Iran , Jafarzadehpur, Ebrahim Department of Optometry - Iran University of Medical Sciences, Tehran, Iran , Yekta, Abbas Ali Department of Optometry - School of Paramedical Sciences - Mashhad University of Medical Sciences , Dadbin, Nooshin Noor Ophthalmology Research Center - Noor Eye Hospital, Tehran, Iran , Khabazkhoob, Mehdi Department of Medical Surgical Nursing - School of Nursing and Midwifery - Shahid Beheshti University of Medical Sciences
Abstract :
Purpose: To estimate the fitting parameters of the hybrid contact lens in patients with corneal ectasia using the rigid gas permeable (RGP) lens.
Methods: Thirty-four eyes with corneal ectasia were evaluated in this study. The patients were examined once with the RGP lens and once with
the hybrid contact lens. The relationship between the base curvature of the RGP and the vault of the hybrid lens and the correlation between their
powers were analyzed.
Results: We found a linear relationship between the base curvature of the RGP lens and the vault of the hybrid lens (P < 0.001) (R2 ¼ 0.45).
Moreover, we found a correlation between the power of the RGP and hybrid lens (P < 0.001) (R2 ¼ 0.4). However, a 0.5 mm decrease in the base
curvature radius of the RGP lens increased the vault of the hybrid lens by 72 m.
Conclusion: The results of this study could be used for better and faster selection of the first hybrid contact lens.
Keywords :
Keratoconus , Hybrid lens , Rigid gas permeable lens , Corneal ectasia
