Abstract
Purpose :
Fluid reservoir (FR) depth is an important component of scleral lens (SL) fitting. Studies have compared instrument-generated values to clinician estimates of FR depth using photographic images and to in vivo slit lamp evaluation by inexperienced clinicians. This study compares measurements of FR depth using Scheimpflug imaging to clinical estimates by experienced SL fitters in established SL wearers.
Methods :
The study was approved by The Ohio State University IRB. Established SL wearers (≥ 6 months of wear with current lens design) from two practices (3 practitioners, each with >10 years of SL fitting experience) were recruited during SL follow-up examinations. Participants wore lenses for at least 2 hours prior to the visit. Scheimpflug images (Pentacam, Oculus) were acquired upon patients’ arrival, and the instrument’s caliper was used to measure FR depth in the center of the vertical image. Clinicians estimated central FR depth at the slit lamp without access to Scheimpflug images.
Descriptive statistics are reported. Mann-Whitney test was performed to evaluate differences between measured and estimated values.
Results :
30 patients (50 eyes) were evaluated. Mean [SD] age was 51.2 [16.2] years (range 21-77); sex distribution was 19 female/11 male. Median [IQR] measured FR depth was 261.5 [130.1] μm (range 40-560μm). Median [IQR] estimated FR depth was 275 [100] μm (range 0-500μm). Comparison of measured and estimated values revealed a collective median [IQR] 7.5 [116.1] μm (range -375 to +260 μm) overestimation of by clinicians. FR depth was underestimated in 27 (54%) eyes. Estimated values were within ±50 μm of measured value in 40% of eyes, within ±100 μm of measured values in 70% of eyes, and within ±150 μm of measured value in 84% of eyes. In remaining eyes, FR depth was underestimated by >150 μm 5 times and overestimated by >150 μm 3 times. Mann-Whitney test showed a difference of -13.5μm (95% CI -55,30) between estimated and measured values (p=0.46).
Conclusions :
Measured FR depth in this cohort of successful SL wearers ranged from 40-560 μm. Differences between estimated and measured values were not statistically significant, but wide variability between these values was noted.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.