Objective To explore the influence on corneal endothelial cell of anterior chamber bubbles during femtosecond laser in situ keratomileusis (LASIK).
Design Retrospective cases series.
Participants Twenty-three patients (23 eyes with anterior chamber bubbles) in The Central Theater Command Air-Force Hospital of PLA from February 2012 to November 2017 who accept LASIK surgeries using femtosecond leaser.
Methods The eyes with anterior chamber bubbles during IntraLase femtosecond laser LASIK were included in observation group, and the eyes without anterior chamber bubbles during LASIK were included in the control group. Anterior chamber bubbles based on the number of bubbles divided into first-level (a little bubbles in pupil area), second-level (medium dose bubbles covering pupil area) and third-level (a lot of bubbles covering completely pupil area). The mean central corneal endothelial cell density(CED), percentage of hexagonal endothelium (HEX) and coefficient of variation(CV) of corneal endothelial cell area measured by Topcon SP-2000P noncontact specular microscope of two groups were compared at preoperation, and at 1 day, 1 week, 1 month, 3 months, 6 months after operation.
Main Outcome Measures CED, percentage of HEX and CV of corneal endothelial cell area.
Results Anterior chamber bubbles located on nasal side in 11 eyes (47.83%), on bitamporal side in 8 eyes (34.78%), on below side in 3 eyes (13.04%) and on upward side in 1 eye (4.35%). All anterior chamber bubbles moved from anterior chamber angle to pupil. 15 eyes (65.22%) were the first-level anterior chamber bubbles, 7 eyes (30.43%) were the second-level and 1 eye (4.35%) was the third-level. The CED of observation group at preoperative and postoperative 1day, 1 week, 1 month, 3 months, 6 months was 2901±180 cells/mm2, 2833±153 cells/mm2, 2852±149/mm2, 2835±171 cells/mm2, 2863±117 cells/mm2 and 2854±88 cells/mm2, respectively. The percentage of HEX of observation group at preoperative and postoperative 1 day, 1 week, 1 month, 3 months, 6 months was 45.2%±5.4%, 46.5%±5.4%, 46.2%±5.4%, 47.3%±5.5%, 47.6%±4.7% and 47.7%±4.5%, respectively. The CV of corneal endothelial cell area of observation group at preoperative and postoperative 1 day, 1 week, 1 month, 3 months, 6 months was 45.17%±5.39%, 46.50%±5.43%, 46.22%±5.43%, 47.32%±5.50%, 47.62%±4.68% and 47.72%±4.52%, respectively. The CED of control group at preoperative and postoperative 1 day, 1 week, 1 month, 3 months, 6 months was 2989±349 cells/mmm2, 2948±246 cells/mm2, 2958±331 cells/mm2, 2972±321 cells/mm2, 2958±342 cells/mm2 and 2962±355 cells/mm2, respectively. The percentage of HEX of control group at preoperative and postoper-ative 1 day, 1 week, 1 month, 3 months, 6 months was 46.3%±7.5%, 44.1%±8.2%, 43.9%±7.3%, 43.7%±7.4%, 44.3%±6.9% and 43.9%±7.1%, respectively. The CV of corneal endothelial cell area of control group at preoperative and postoperative 1 day, 1 week, 1 month, 3 months, 6 months was 43.81%±8.15%, 46.41%±6.37%, 46.58%±6.67%, 46.73%±7.12%, 46.81%±6.12% and 46.76%±7.06%, respectively. The difference of CED between control group and observation group was statistically significant (F=2.486, P=0.022), and the difference between postoperative and preoperative parameters of CED in the same group was not statistically significant (F=1.342, P=0.260). The difference of percentage of HEX between control group and observation group was not statistically significant (F=0.469, P=0.497), and the difference between postoperative and preoperative parameters of percentage of HEX in the same group was statistically significant (F=5.966, P=0.004). The difference of CV of corneal endothelial cell area between control group and observation group was not statistically significant (F=0.4106, P=0.746), and the difference between postoperative and preoperative parameters of CV of corneal endothelial cell area in the same group was statistically significant (F=21.248, P=0.000).
Conclusion The anterior chamber bubbles produced in femtosecond laser LASIK have a certain effect on CED in a short time. However, it had no significant effect on percentage of HEX and CV of corneal endothelial cell area. (Ophthalmol CHN, 2021, 30: 360-366)