소프트콘택트렌즈 처방법에 따른 직난시안의 각막수차 및 대비감도 비교

Purpose: This study aimed to investigate the effect of changes in temperature and humidity on the stability of ophthalmic lenses. Methods: Combining temperatures of 35oC and 80oC, and relative humidity of 30% and 85% under four conditions, ophthalmic lenses of −1.00, −5.00, and −8.00 D with high refractive index (n=1.60) were exposed for 24, 72, and 120 h and the changes in parameters and coating films were compared. Results: Lenses exposed to a low temperature (35oC) exhibited no change of surfaces and characteristics regardless of humidity; however, lenses exposed to a high temperature (80oC) exhibited changes in spherical and cylindrical refractive powers, a decrease in contact angle by up to approximately 5%, a decrease in adherence grade, and deeper and larger surface cracks appearing from the center to the periphery. These changes were larger with an increase in exposure time, and a greater change was observed under high humidity conditions compared to that under low humidity. Meanwhile, under the same conditions of temperature and humidity, the degree of changes in ophthalmic lenses according to the refractive power was larger at −5.00 D and −8.00 D compared to −1.00 D. Conclusions: High- or low humidity had a greater influence on the coating film and characteristics under a high-temperature environment. Thus, if an ophthalmic lens is exposed to a high temperature and humidity environment for prolonged periods, stability may not be guaranteed even if the replacement cycle recommended by the manufacturer is followed; therefore, considering these conditions and inspecting the ophthalmic lenses may be suggested.