PMMA lenses worn for twenty years.

Area of Science:

• Ophthalmology
• Corneal Science
• Contact Lens Research

Background:

• Polymethyl methacrylate (PMMA) contact lenses have been used for decades.
• Understanding the long-term effects of PMMA lens wear on corneal structure is crucial for patient eye health.

Purpose of the Study:

• To evaluate the long-term impact of PMMA contact lens wear on corneal curvature and refractive stability.
• To assess changes in corneal toricity and astigmatism after extended PMMA lens use.

Main Methods:

• Study included 150 eyes from 75 patients with a history of PMMA lens wear for at least twenty years.
• Corneal curvature, toricity, and refractive error (spherical and cylinder Rx) were analyzed.
• Biomicroscopic examinations were performed to assess corneal integrity.

Main Results:

• Most patients exhibited only minor alterations in corneal curvature.
• Twenty-seven percent of eyes showed no change in corneal toricity, despite refractive shifts up to +/- 3.00 D.
• Forty eyes maintained consistent cylinder correction, and 13 eyes had unchanged spherical correction.
• Statistical analysis indicated limited significant changes in corneal curvature.

Conclusions:

• Long-term PMMA contact lens wear is associated with generally stable corneal curvature.
• While some patients develop astigmatism, a significant portion retains corneal toricity and refractive stability.
• Biomicroscopic findings suggest no serious adverse conditions related to long-term PMMA lens wear.