Abstract:   Objective  To observe the clinical efficacy of wearing scleral lenses in patients with keratoconus. Design  Retrospective case series. Participants 21 patients (29 eyes) with keratoconus of completion period stage 3 or below and fitted with scleral lenses at the Affiliated Eye Hospital of Nanjing Medical University. Methods All patients underwent a standard fitting procedure for scleral lenses. The fitting status of scleral lenses, as well as the differences in tear film clearance between the lenses and the central and peripheral cornea at 1 week, 1 month, 3 months, and 6 months was observed and compared. Changes in visual acuity, refractive error, corneal parameters, and other indicators were compared between baseline (before wearing glasses), at 1 week, 1 month, 3 months, and 6 months of wearing scleral lenses. Patients completed the NEI-VFQ-25 questionnaire to assess the quality of life and vision of wearing scleral lenses for 6 months. Main Outcome Measures Corrected visual acuity, intraocular pressure (IOP), flat anterior corneal surface refractive power (K1), steep anterior corneal surface refractive power (K2), steepest anterior corneal surface refractive power (Kmax), corneal thinnest point thickness (TCT), center corneal thickness (CCT), corneal staining score (CSS), corneal endothelial cell density (ECD), NEI-VFQ-25 scores, tear film clearance. Results At 6 months of wearing scleral lenses, the tear film clearance in the central, nasal, temporal, upper, and lower regions of the scleral lenses were 221 (177, 274)μm, 98 (68, 133)μm, 138 (81, 213)μm, 145 (95, 190)μm and 360 (289, 478)μm, respectively, there was no significant differences compared to the 240 (184, 282)μm, 98 (62, 121)μm, 120 (95，207)μm, 145 (82，192)μm and 326 (270, 450)μm at 1 week of wearing scleral lenses (all P>0.05). At 1 week and 6 months of wearing scleral lenses, the corrected visual acuity with scleral lenses was 0.30 (0.05, 0.40) LogMAR and 0.22 (0.02, 0.30) LogMAR, respectively, which were significantly improved compared to the corrected visual acuity with frame glasses of 0.52 (0.22, 0.76) LogMAR (P=0.013, P=0.001). Before wearing scleral lenses, at 1 week and 6 months, K1 was (57.70±10.71) D, (58.05±10.90) D and (58.43±11.20) D, K2 was (63.25±13.17) D, (63.42±13.22) D and (63.24±13.00) D, Kmax was (72.60±16.94) D, (72.46±16.47) D and (72.30±16.04) D, TCT was 410 (356, 453)μm, 416 (362, 457)μm and 400 (336, 462)μm, CCT was (410.55±74.25) μm, (416.93±80.98) μm and (421.31±81.56) μm, IOP was (10.38±3.91) mmHg, (10.41±4.63) mmHg and (9.79±4.29) mmHg, CSS was 0 (0,1), 0 (0,1)and 0 (0,1), with no statistically significant differences at each time point (all P>0.05). After wearing scleral lenses for 6 months, the ECD was 2905 (2542, 3019.5) cells/mm2, and there was no significant change compared to 2876 (2659, 3148.5) cells/mm2 before wearing scleral lenses (P=0.691). After wearing scleral lenses for 6 months, the patients'NEI-VFQ-25 score was 2175 (1925, 2450), which was significantly higher than 1750 (1337.5, 2025) before wearing scleral lenses (P=0.001). Conclusions The 6-month observation results of this small sample size indicate that scleral lenses have good corrective effects and safety in patients with keratoconus at completion period stage 3 or below, and wearing scleral lenses significantly improves the visual function and quality of life of keratoconus patients.
  

Key words: Keratoconus, Scleral lens, Clinical correction effectiveness