Limbal-Rigid Contact Lens Wear for the Treatment of Ocular Surface Disorders: A Review

Abstract

Recently, the prescription of large-diameter rigid gas-permeable contact lenses (CLs), also known as "scleral lenses," "corneoscleral lenses," and "limbal-rigid CLs," is on the rise for the treatment of both moderate and severe ocular surface disorders (OSDs). Compared with scleral lenses, the diameter of limbal-rigid CLs is generally smaller, that is, a diameter ranging from 13.0 to 14.0 mm, and they are designed so that the peripheral edge bears on the limbus. The Suncon Kyoto-CS (Sun Contact Lens Co., Ltd.) is a novel limbal-rigid CL design with multistep curves on the peripheral edge for easy tear exchange during blinking that removes debris and prevents lens clouding or fogging, thus allowing patients to enjoy a longer daily duration of CL wear. In severe OSD cases, limbal-rigid CL wear after surgery is a noninvasive therapeutic approach that can neutralize corneal irregularities, decrease dry eye symptoms, prevent the progression or recurrence of symblepharon, and improve the patient's visual acuity and overall quality of life. Thus, surgeries such as amniotic membrane transplantation and cultivated oral mucosal epithelial transplantation, as well as limbal-rigid CL wear, which is noninvasive, are valuable and effective treatment strategies that can now be applied for the management of patients afflicted with severe OSDs.

FIG. 1.

Limbal-rigid contact lens (CL) design. (A) Schema illustrating the lens design. (B) Schema illustrating the multicurve design of the peripheral edge of the lens. (C) Anterior-segment optical coherence tomography (AS-OCT) image of the limbal-rigid CL. Moderate OSD case: a. clinical finding image without a CL; b. fluorescein staining evaluation; c. AS-OCT image with the tear layer shown by arrow. Severe OSD case: d. clinical finding image without a CL; e. fluorescein staining evaluation; f. AS-OCT image with the tear layer shown by arrow. BC, base curve; IC, intermediate curve; PC, peripheral curve.

FIG. 2.

Limbal-rigid CL fitting algorithm. The fitting begins with a 7.90-mm base curve, a 14.0-mm diameter, an 8.50-mm optical zone, and a flat peripheral edge design (N). The fluorescein staining pattern is used to evaluate the centration, the dynamic fit of the lens, and the pooling of the tears. A 13.0-mm diameter lens is used if the lens is found to be too large of a size to properly fit on the eye. A best-fit lens is defined as the lens parallel to the cornea with a moderate tear layer in the sclera. If the sagittal depth is deep, change the lens to a 9.00-mm optical zone. Then re-evaluate the fluorescein staining pattern. After confirming the lens, evaluate the peripheral edge of the lens. If the peripheral edge is lifted, change the peripheral edge lens type into tight type (T). Then continue with subjective visual acuity examination. T, tight peripheral edge design; N, flat peripheral edge design; OZ, optical zone; SAG, sagittal depth.

FIG. 3.

Average best-corrected visual acuity (BCVA) changes in each group. Graph showing the changes of BCVA between at baseline (i.e., before fitting) and at 3 months after the initiation of CL wear in group 1 (logMAR BCVA>2.0), group 2 (2≥logMAR BCVA>1), and group 3 (1≥logMAR BCVA).

FIG. 4.

Representative clinical findings on the eyes at baseline and at 3 months after the initiation of CL wear. Clinical findings on the eyes treated with limbal-rigid CL wear only, in combination with amniotic membrane transplantation, and in combination with cultivated oral mucosal epithelial transplantation (COMET).