Is soft toric contact lenses fitting a feasible option to improve optical quality and visual performance in corneal ectasia?

OBJECTIVES

To assess the feasibility of fitting soft toric contact lenses (STCL) in corneal ectasias and their impact on optical quality and visual performance.

METHODS

A total of 22 eyes were fitted with a molded STCL: 11 eyes/9 subjects with corneal ectasia and 11 healthy eyes/11 subjects. Wavefront aberrations were analyzed using a Hartmann-Shack aberrometer. Visual performance was measured under photopic (85 cd/m 2) and mesopic (≤3 cd/m 2) conditions. High-(96 %) and low- (10 %) contrast VA (HCVA and LCVA respectively) were assessed using the ETDRS charts and contrast sensitivity (CS) using the Pelli-Robson chart.

RESULTS

After STCL fitting in the ectatic corneas, oblique astigmatism increased 0.15±0.17 μm and 0.34 ± 0.36 μm for 3 mm- and mesopic pupil diameters, respectively. Mean defocus decreased 1.41 ± 0.36 μm and 2.17 ± 0.85 μm for the same pupil diameters. More positive values of vertical coma were found with a change of 0.05 ± 0.06 μm and 0.12 ± 0.10 μm for 3 mm and mesopic pupil diameters, respectively. Comparing changes between both groups, with a 3 mm pupil aperture, statistically significant differences (p < 0.05) were detected in oblique astigmatism, defocus, vertical secondary trefoil and horizontal secondary coma. In the group with corneal ectasia, photopic HCVA and LCVA improved 0.09 ± 0.11 logMAR and 0.12 ± 0.15 logMAR respectively. In mesopic conditions, HCVA, LCVA and CS improved 0.11 ± 0.12 logMAR, 0.18 ± 0.15 logMAR and 0.11 ± 0.07 log. units, respectively.

CONCLUSIONS

The analyzed molded soft toric contact lens is a feasible option for good vision in corneal ectasia with moderate irregularity and negative vertical coma.