Intraocular pressure variation associated with the wear of large corneal rigid gas permeable lenses.

PURPOSE: Speciality contact lenses are utilized for both ocular surface disorders and refractive error corrections. Common and widely used among them are large corneal rigid gas permeable lenses such as corneo-scleral and mini-scleral lenses. These lenses are designed to rest on the conjunctival tissue overlying the sclera to create a vault over the entire cornea and limbus. The lenses fit in and settle into conjunctival tissue, compressing the collector channels and episcleral veins, directly affecting the aqueous outflow. Consequently, an increase in intraocular pressure (IOP) is anticipated. This study aims to determine the effect of large corneal lens wear over IOP. This included evaluation of IOP variations, corneal thickness variations, and topographic changes before and after large corneal rigid gas permeable lens wear.

METHODS: An interventional study was performed on 30 subjects who had attended the outpatient department of the institute and undergone ophthalmic and medical examinations along with contact lens fitting tests. IOP, corneal thickness, and corneal curvature measurements were captured before and immediately following 6 h of lens wear.

RESULTS: The average value of intra-ocular pressure before wearing lenses was 11.77 ± 1.77 mmHg and after wearing corneoscleral lenses was 12.17 ± 1.96 mmHg and mini-scleral lens was 12.03 ± 1.92 mmHg. Average values of central corneal thickness (CCT) before wearing lenses were 531.07 ± 20.58 μm and after wearing were 537.33 ± 20.68 μm for corneo-scleral lens and 540.60 ± 20.30 μm for mini-scleral lens.

CONCLUSION: There was substantial increase in intra-ocular pressure and CCT after wearing both corneo-scleral lens and mini-scleral lens for 6 h. There were no significant changes seen in corneal curvature after wearing both lenses.