Zenlens scleral lenses for visual rehabilitation of patients with irregular cornea: a usage experience

Scleral lenses improve visual acuity in patients with irregular corneal astigmatism, which is especially important when other methods of correction are ineffective.

Purpose: to assess the efficiency of Zenlens scleral lenses in patients with irregular cornea.

Material and methods. A total of 120 patients (164 eyes) were examined, including 86 males and 34 females, aged from 13 to 63 years (mean age 35 ± 12 years). The patients were divided into 4 groups. Group 1 consisted of patients with keratoconus, group 2 — postpenetrating keratoplasty, group 3 — keratoconus after cross-linking and/or corneal ring segment implantation, while group 4 consisted of patients with other diseases. The efficiency criteria included visual acuity before and after scleral lens fitting and wearing time (hours per day). To determine social significance of scleral lens wearing, we selected 30 patients (46 eyes) with average best-corrected visual acuity (BCVA) before fitting 0.21 ± 0.08 (0.1–0.3).

Results. Average uncorrected visual acuity before fitting did not exceed 0.2 and average visual acuity after fitting was 0.8 ± 0.15. Average improvement in visual acuity after fitting compared to uncorrected visual acuity was at least six lines in all groups and average improvement of visual acuity was approximately three lines compared to BCVA before fitting. 74.4 % and 19.5 % of patients demonstrated long-term (> 10 hours per day) and partial (8–10 hours per day) wear, respectively. Short-term wear (< 8 hours per day) was noted in 6.1 % of patients. Visual acuity of  patients with low BCVA (mean 0.21 ± 0.08) increased by 0.57 (271.4 %).

Conclusion. Scleral lenses can be successfully used for visual acuity improvement and social rehabilitation of patients with irregular cornea when other methods of correction are ineffective. 

1. Foss A.J.E., Trodd T.C., Dart J.K.G. Current indications for scleral contact lenses. CLAO J. 1994; 20: 115–8.

2. Kok J.H.C., Visser R. Treatment of ocular disorders and dry eyes with high gas-permeable scleral lenses. Cornea 1992; 11: 518–22.

3. Romero-Rangel T., Stavrou P., Cotter J., et al. Gas-permeable scleral contact lens therapy in ocular surface disease. Am. J. Ophthalmol. 2000; 130: 25–32.

4. Rosenthal P., Cotter J. Clinical performance of a spline-based apical vaulting keratoconus corneal contact lens design. CLAO J. 1995; 21: 42–6.

5. Rosenthal P., Croteau A. Fluid-ventilated, gas-permeable scleral contact lens is an effective option for managing severe ocular surface disease and many corneal disorders that would otherwise require penetrating keratoplasty. Eye Contact Lens. 2005; 31: 130–4.

6. Segal O., Barkana Y., Hourovitz D., et al. Scleral lenses help where other modalities fail. Cornea. 2003; 22: 308–10.

7. Smiddy W.E., Hamburg T.R., Kracher G.P., et al. Keratoconus. Contact lens or keratoplasty? Ophthalmology. 1988; 95: 487–92.

8. Ridley F. Scleral contact lenses. Arch. Ophthalmol. 1963; 70: 740–5.

9. Visser E.S., Visser R., van Lier H.J., et al. Modern scleral lenses. Part II: Patient satisfaction. Eye Contact Lens. 2007; 33: 5–21.

10. Ezekiel D. Gas permeable haptic lenses. J. Br. Contact Lens Assoc. 1983; 6: 158–61.

11. Lyons C.J., Buckley R.J., Pullum K.W., et al. Development of the gas-permeable impression-moulded scleral contact lens. A preliminary report. Acta Ophthalmol. Suppl. 1989; 192: 162–4.

12. Ruben C.M., Benjamin W.J. Scleral contact lenses: Preliminary report on oxygen-permeable materials. Contact Lens J. 1985; 13: 5–9.

13. Schein O.D., Rosenthal P., Ducharme C. A gas-permeable scleral contact lens for visual rehabilitation. Am J. Ophthalmol. 1990; 109: 318–22.

14. Tan D.H.T., Pullum K.W., Buckley R.J. Medical applications of scleral contact lenses: 1. A retrospective analysis of 343 cases. Cornea. 1995; 14: 121–9.

15. Stechschulte S.U., Azar D.T. Complications after penetrating keratoplasty. Int. Ophthalmol. Clin. 2000; 40: 27–43.