Clinical efficacy of laser subepithelial keratomileusis in the treatment of thin corneal myopia

AIM: To compare the clinical efficacy of laser subepithelial keratomileusis(LASEK)in the treatment of myopia with normal corneal thickness and myopia with thin corneal thickness.METHODS: This study was a prospective controlled study. Totally 55 patients(103 eyes)with myopia who underwent LASEK surgery in the 983rd Hospital of Joint Logistics Support Force of Chinese People's Liberation Army between June 2023 and February 2024 were selected. According to the central corneal thickness, there were 27 patients(50 eyes)of myopia with thin corneal thickness(460-499 μm)and 28 patients(53 eyes)of myopia with normal corneal thickness(500-550 μm). The patients were followed up before operation, and at 1 wk, 1, 2, 3 and 4 mo postoperatively. The uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), spherical equivalent(SE), residual corneal thickness, intraocular pressure(IOP), corneal irritation, and corneal haze were recorded, and the safety index and efficacy index were calculated. The measured indexes were analyzed statistically.RESULTS: There were no significant differences in preoperative gender composition, age, SE, UCVA or BCVA between the two groups(all P>0.05). There were no significant differences in UCVA between the two groups of patients and the interaction(all P>0.05); the UCVA of the two groups were improved at every time after surgery(P<0.001). There were no significant differences in the safety index and efficacy index between the two groups after 4 mo(all P>0.05). There were no differences in SE interaction between the two groups of patients before and after surgery(P>0.05), as well as in the comparison of time(all P<0.05), the SE of the two groups were decreased significantly at every time after surgery, and there was a slight myopic drift at early postoperative stage in the thin corneal thickness myopia group. There were no differences in ΔIOP between the two groups of patients before and after surgery, as well as in the comparison of time and interaction(all P>0.05). There were no significant differences in corneal irritation and corneal haze between the two groups(all P>0.05). There was a positive correlation between the remaining postoperative corneal thickness and preoperative corneal thickness, preoperative SE, SE and IOP at 4 mo postoperatively(all P<0.05).CONCLUSION: LASEK in the treatment of thin corneal myopia is as safe and effective as normal corneal thickness myopia.