Purpose. To describe the vision-correcting and therapeutic benefits of gas-permeable scleral contact lenses (GP-ScCL) in the management of irregular corneal surface disorders and ocular surface diseases.
Methods. The charts of 48 consecutive patients (66 eyes) whose management included the use of GP-ScCL were reviewed.
Results. The most common indication for fitting the lenses was keratoconus in patients who had to stop wearing other types of corneal lenses (44 eyes, 74.6%). Other indications included extreme corneal irregularity after penetrating keratoplasty, nonhealing corneal ulcer, postoperative dry eye syndrome following laser in situ keratomileusis (LASIK), severe exposure keratitis and acid burn. Mean follow-up was 17 months (range, 2–96). Mean wearing time of the GP-ScCL was 16.2 hours per day (range, 3–18). Visual acuity of 20/40 or better was achieved in 90.9% of keratoconus patients and in 81.8% of postkeratoplasty patients. A gain of two or more Snellen lines was observed in 94.5% of eyes treated for improving vision. Marked subjective improvement in quality of life was reported by 86% of the patients, mainly as a result of improvement in their visual function and reduction in discomfort. Five patients (seven eyes) failed to wear GP-ScCL.
Conclusion. GP-ScCL can provide successful and safe visual and therapeutic solutions for ocular conditions when conventional contact lenses and medical treatment have failed and where surgery is undesirable or contraindicated.
In some patients with corneal irregularity, vision cannot be improved with rigid corneal contact lenses, either because of poor lens centration or inability to fit such a lens. Some cases of nonhealing corneal epithelial defects and other ocular surface diseases do not resolve with currently available therapeutic modalities, which include patching, lubrication, soft contact lens extended wear, tarsorrhaphy, and, recently, the surgical application of amniotic membrane. 1,2 Both of these conditions, corneal irregularity and corneal surface disorders, can be treated with scleral contact lenses (ScCL). These lenses offer two unique advantages. One is that they are supported by the sclera and therefore can be fitted on eyes with markedly irregular corneas. The second is the constant aqueous reservoir between the lens and the cornea. This reservoir neutralizes most of the irregular astigmatism and protects the corneal surface from the desiccating effects of exposure to air and the friction of blinking. Until recently, these advantages could not be fully realized because of chronic corneal hypoxia attributed to low gaseous permeability of polymethyl methacrylate (PMMA) and other materials from which the lenses were made. 3–5 By significantly reducing this complication, the introduction of rigid materials with high gas-permeable properties has brought renewed interest in scleral contact lenses for the treatment of ocular surface disorders and the visual rehabilitation of patients with markedly irregular corneas.
The use of ScCL today is still quite limited. Only a few publications have addressed the characteristics and results of this treatment modality. In this study, we report our experience in fitting patients with gas-permeable ScCL (GP-ScCL). By demonstrating our success, we might encourage others to use this method.
From the Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel.
Submitted October 25, 2002.
Revision received February 24, 2003.
Accepted March 4, 2003.
Address correspondence and reprint request to Ori Segal, M.D., Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin 70300, Israel. E-mail: email@example.com