Abstract:

Objective

The aim of this study is to observe the changes of adjustment function in patients with anisometropia after small incision lenticle extraction（SMILE）.

Methods

Thirty-two cases（64 eyes）with anisometropia registered at the Ophthalmology Department of Hospital Handan Eye from January 2023 to October 2023 were retrospectively analyzed.Among them，there were 8 males（16 eyes）and 24 females（48 eyes）with an average age of（27.2±5.0）years（ranged from 18 to 33 years）.They were received SMILE for both eyes.Their equivalent spherical lens，uncorrected visual acuity，best corrected visual acuity，stereopsis，positive and negative relative accommodation（PRA/NRA） ，accommodation response（BCC），accommodative facility（AF），accommodative amplitude（AMP）were measured before surgery and 3 months after surgery.The data conformed the normal distribution were expressed as±s.Paired sample t test was used before and after surgery.The comparison of stereopsis before and after surgery was conducted using McNemar's paired chi-square test.

Results

Before surgery，the patient's spherical equivalent， binocular refractive difference，uncorrected visual acuity and best corrected visual acuity were（-5.03±2.19）D，（2.61±1.00）D，（0.51±0.75）logMAR and（0.05±0.03）logMAR respectively.Three months after surgery，they were（0.00±0.70）D，（0.18±0.59）D，（0.08±0.18）logMAR and（0.07±0.17）logMAR，respectively.The differences before and after surgery were statistically significant（t=-13.40，-9.46，-16.28，-2.15；P＜0.05）.Before surgery，25 cases（50 eyes）had stereoscopic vision function（central stereopsis＞60"and ＜800"），accounting for 78%；three months after surgery，30 cases（60 eyes）had postoperative stereoscopic vision function（＞60"and＜800"），accounting for 93%.There was no significant difference in stereoscopic vision function before and after surgery（P＞0.05）.Before surgery，the PRA，NRA，BCC，AF，AMP were（-2.27±1.55）D，（1.82±0.55）D，（-0.03±0.59）D，（7.33±5.26）cpm and 11.84±3.29，respectively.Three months after surgery，they were（-1.90±1.06）D，（2.07±0.57）D，（0.05±0.27）D，（7.73±3.65）cpmand 11.37±4.70，respectively.There were no significant differences in PRA，NRA，BCC and AF before and after surgery（t=-0.61，-1.00，-0.31，-0.27；P＞0.05）；the difference in AMP before and after surgery was statistically significant（t=-2.17，P＜0.05）.For the right eye，the AF and AMP before surgery were（4.78±4.38）cpm and 8.15±1.36，respectively.Three months after surgery，they were（5.50±4.92）cpm and 10.1±3.63，respectively.There was no significant difference in AF before and after surgery（t=0.68，P＞0.05）；the difference in AMP before and after surgery was statistically significant（t=2.38，P＜0.05）.For the left eye，the AF and AMP before surgery were（6.59±5.19）cpm and 10.38±4.80，respectively.Three months after surgery，the AF and AMP were（5.40±4.03）cpm and 9.52±4.59，respectively.There were no significant differences in AF and AMP before and after surgery（t=2.19，0.57；P＞0.05）.

Conclusions

SMILE surgery has good efficacy and safety in the treatment of myopic anisometropia，and can significantly improve patients'visual function and visual quality.

Key words: Anisometropia, Refractive surgery, Accommodate, Visual function