Surgically Induced Astigmatic Change after Laser in Situ Keratomileusis using Manual Microkeratome.

Lee, Jong Seok; Bae, Sun Ryang; Joo, Choun Ki

Original Article

Journal of the Korean Ophthalmological Society 2000;41(2):365-370.
Published online February 1, 2000.

Surgically Induced Astigmatic Change after Laser in Situ Keratomileusis using Manual Microkeratome.

Jong Seok Lee, Sun Ryang Bae, Choun Ki Joo

¹Department of Ophthalmology, Kangnam St.Mary's Hospital, College of Medicine, The Catholic University of Korea.
²Department of Ophthalmology, Taejeon St.Mary.

수동 미세각막절삭기를 이용한 라식 근시교정술후 유발된 난시의 변화

이종석(Jong Seok Lee),배선량(Sun Ryang Bae),주천기(Choun Ki Joo)

Abstract

We performed spherical LASIK operations using manual microkeratome and assessed the axis and magnitude of surgically induced astigmatism by vector analysis[Jaffe's rectangular coordinates]. Six month follow-up of 124eyes of 98 patients who were followed for 6 months or longer were included. Myopia ranged from -4.00 to -9.75 diopter. We divided eyes depending on the degree of myopia;group 1, 31 eyes between -4.00 and -5.75 diopter, group 2, 46 eyes between -6.00 and -7 .75 diopter, and group 3, 47 eyes between -8.00 and -9.75 diopter. Also, we compared the axis of surgically induced astigmatism between right eyes[73 eyes]and left eyes[48 eyes]. Preoperative astigmatic refraction was -0.63 +/-0.30 diopter in group 1, -0.67 +/-0.35 diopter in group 2, -0.67 +/-0.41 diopter in group 3.After 2 months, magnitude of surgically induced astigmatism was 0.84 +/-0.57 diopter in group 1, 1.08 +/-0.72 diopter in group 2, 1.19 +/-0.84 diopter in group 3[P=0.15], after 6 months, 1.01 +/-0.59 diopter in group 1, 1.16 +/-0.98 diopter in group 2, and 0.99 +/-0.59 diopter in group 3[P=0.52]. Change in the axis of vectorial-induced astigmatism was not statistically significant between right eyes and left eyes after 2 months[P=0.16], but significant after 6 months[p<0.05 ]. In conclusion, spherical LASIK using manual microkeratome may induce a significant change in magnitude of the astigmatism regardless the degree of myopia. The difference of astigmatic axis was statistically significant between right eyes and left eyes after 6 months. These changes and differences may require long-term follow-up and further investigation.

Key Words: Spherical LASIK;Surgically induced astigmatism;Vector analysis