Study Of Accommodation And Nonstrabismic Binocular Anomalies After ICL On High Myopia

Purpose: Comparing the type of accommodation and nonstrabismic binocular anomalies before and after Implantable Collamer Lens(ICL) implantation on high myopiaMethods: The study selected 30 patients with high myopia, whose ages are among 20 to 35 years old(average is 28), spherical power from-10.00 D to-20.00D(average is-16.25D), and cylindrical power from 0 to-5.00D(average is-3.75D). Before and 1st、3rd、6th months after the ICL implant, binocular visual function were examined respectively under best corrected visual acuity with the test-object at the previous line(including DLP(Distant lateral phoria)、NLP(Near lateral phoria)、DPFV(Distant positive fusion vergence)、DNFV(Distant negative fusion vergence)、NPFV(Near positive fusion vergence)、NNFV(Near negative fusion vergence)、AC/A(Accommodative convergence/ Accommodation)、AF(Accommodation of facility)、BCC(Binocular Cross-cylinder)、NRA/ PRA(Positive relative accommodation/Negative relative accommodation)、AMP(Amplitude of accommodation)).The study analyzed type of accommodation and nonstrabismic binocular anomalies during different periods.Results: Before ICL operation, 22(73.33%) of them was free from binocular single vision.Specifically,there were 18(60%) patients with monocular inhibitions and 4(13.3%) patients with diplopia. After ICL, there was no suppression or diplopia, and all(100%) binocular single vision were observed.Meanwhile,before ICL 8 patients(26.67%) had accommodative dysfunctions and 22 patients(73.33%) had binocular dysfunctions.After ICL, 29(96.67%) patients had accommodative insufficiency and 1(3.33%) patient had convergence insufficiency and accommodative insufficiency. And for the phase comparison, there is no statistical significance for the change of DLP, DPFV, DNFV, NPFV, NNFV, BCC, NRA; For NLP(F=6.395, P < 0.05), PRA(F=5.066, P < 0.05), AMP(F=20.116, P < 0.05 in the right eye; F=20.723, P < 0.05 in the left eye) decreasing significantly after the operation, the differences were statistically significant; In virtue of AC/A(F=3.982, P < 0.05), AF(F=3.338, P < 0.05 in the right eye; F=4.055, P < 0.05 in the left eye; F=4.722, P < 0.05 in the binoculus) postoperatively increasing, the differences were also statistically significant; Besides the AMP of 30 patients were decreased(100%); And the UBM of all patients show the position of intraocular lens was close to the ciliary body and the suspensory ligaments.Conclusion: Patients with high myopia has accommodation and nonstrabismic binocular anomalies of different type and degrees. ICL implantation can reduce patients’ myopic power and improve their binocular single vision.But it further lead to accommodation deficiency, which may results in difficult in seeing objects close distance.