Scleral Lens Improves Vision, Reduces Aberrations in Patients With Keratoconus

A specific scleral contact lens (CL) design may improve visual acuity (VA) and correct both high and low order aberrations in patients with keratoconus (KC), according to a study published in Eye and Vision. Some pre-fitting variables may predict these VA improvements.

Researchers retrospectively reviewed data from 15 patients (eyes, 30; 33% women, mean age, 34.5 years) with KC fitted with a specific scleral CL. Of the 30 eyes included, 15 (50%) received no previous treatment, 10 (33.3%) had been treated with corneal crosslinking (CXL), and 5 (16.7%) received intracorneal ring segment implantations. 

Visual, refractive, tomographical, and ocular aberrometric changes were evaluated over the 3 months study duration. Central, temporal, and nasal lens vault measurements were obtained through optical coherence tomography (OCT).  

Patients’ VA increased significantly from a mean [SD] 0.23 [0.07] logarithm of the minimal angle of resolution (logMAR) to 0.10 [0.04] logMAR after 1 month of lens wear (P<.001) and a total of 62.1% of participants experienced a VA improvement of 1 or more lines. 

Significant decreases in central, nasal, and temporal vaults occurred after 1 month of wear (P ≤.046) and there was a significant difference (62.91 µm; P =.008) between nasal and temporal vaults during this time. 

Reductions in ocular high order ocular aberrations and primary coma root mean square were observed among the cohort. Median higher order aberration root mean square was reduced by 41.9% and primary coma was reduced by 50.5%, according to the report. Baseline corrected VA, scleral lens power, and sagittal height were used to create a linear equation that predicted changes in visual acuity achievable with the scleral lens (P <.001; R²=0.878). 

“A significant decrease was observed with the CL in [higher order aberrations] and primary coma [root mean square], confirming the ability of this type of CL to minimize the aberrations that are present in KC eyes and to improve the ocular optical quality,” according to researchers.

Study limitations include a retrospective nature, small sample size, and possible measurement bias due to OCT measurements conducted by a single researcher.