Scleral lens influence on corneal curvature and pachymetry in keratoconus patients

Objectives.
To investigate the influence of full scleral lenses on corneal curvature and pachymetry in keratoconus patients.

Methods.
In this intervention study, 20 eyes of 14 patients were measured by Scheimpflug imaging (Pentacam HR, Oculus) at two time points: directly and ≥1 week after scleral lens removal. Steep, flat and maximal keratometry (Ksteep, Kflat and Kmax) and optical pachymetry were analyzed. A generalized estimating equation analysis was performed to correct for paired eyes.

Results.
Directly after scleral lens removal, all three curvature parameters were significantly flatter com-pared to ≥1 week after scleral lens removal. Average Ksteep was 0.7 diopter (D) lower (P < 0.001), average Kflat was 0.5 D lower (P = 0.037) and average Kmax was 1.1 D lower (P < 0.001). Directly after scleral lens removal, average optical pachymetry was ±2.5% higher (P < 0.001) compared to ≥1 week after scleral lens removal.

Conclusions.
Although scleral lenses do not mechanically touch the cornea, curvature and pachymetry seem to be influenced by scleral lens wear in keratoconus patients. The duration of these changes remain unclear.

The entire article is published in Contact Lens & Anterior Eye, Volume 38, 2015, pp. 294-297. Link to the article.