Management of Keratoconus With Corneal Rigid Gas-Permeable Contact Lenses

Evidence of Contact Lenses for Vision Rehabilitation in Corneal Diseases: A Review

OBJECTIVES

To evaluate the efficacy and safety of contact lenses (CL) as a therapeutic option for patients affected by a corneal disease and to determinate which is the best lens modality for each disease.

METHODS

A literature review using PubMed was performed. All relevant articles published during the last 15 years have been included.

RESULTS

Various studies point to CL as the best therapeutic option for some corneal diseases and even as an alternative to surgery in some cases. After fitting, patients show an improvement in their functional vision and quality of life, in some cases being able to drive or work again.

CONCLUSIONS

There is a lack of scientific evidence to determine which lens modality is suitable for each corneal pathology. Currently, according to this review, the reason for choosing between the different options depends on the severity of symptoms, and it is worth mentioning that scleral lenses seem to be the best option in advanced stages of disease. However, the expertise of professionals is also an important factor at the time of choosing a particular CL modality. Standardized criteria are still necessary for correct selection of lens modality for a correct management of the disease.

Corneal RGP Contact Lens Fitting Software for Keratoconus Built-In Anterior Segment Optical Coherence Tomography

OBJECTIVE

To assess the performance of the contact lens fitting software built into anterior segment optical coherence tomography (AS-OCT).

METHODS

This retrospective study enrolled patients with keratoconus prescribed with spherical corneal rigid gas-permeable contact lenses based on a contact lens fitting software. Subjects were classified into four subgroups based on corneal morphology: nipple, oval, globus, and marginal type. Software performance was evaluated according to the correlation between the back optical zone radius (BOZR) calculated by the contact lens fitting program and the BOZR of the lens prescribed, and the number of trial lens replacements required.Results:A total of 340 eyes of 254 patients with a mean age of 40.4 ± 13.6 years were included. The oval type was the most common (61.8%), followed by the nipple type (26.2%). Linear regression analysis revealed a significant correlation between the prescribed and the calculated BOZR in all subgroups (R 2 = 0.92, P < 0.01 for the nipple type; R 2 = 0.76, P < 0.01 for the oval type; R 2 = 0.93, P < 0.01 for the globus type; and R 2 = 0.79, P < 0.01 for the marginal type). Furthermore, the globus type had the highest proportion of cases requiring at least one trial lens replacement (36.3%), followed by the nipple group (27.0%). There were no significant differences among the subgroups ( P = 0.14).

CONCLUSIONS

In conclusion, our findings reveal that the contact lens fitting software built into AS-OCT may be useful for accurate contact lens prescription for any corneal shape.