Clinical Characteristics and Early Visual Outcomes of Highly Myopic Cataract Eyes: The Shanghai High Myopia Study

Purpose: To report ocular characteristics and early visual outcomes of highly myopic cataract eyes, and to analyze the risk factors of low vision. Methods: A total of 2,027 eyes of 1,400 cataract patients with axial length (AL) ≥ 26 mm undergoing cataract surgery in Eye & ENT Hospital of Fudan University, who were registered in the Shanghai High Myopia Study, were analyzed. Routine pre-operative ophthalmic examinations were performed and macular scan of optical coherence tomography (OCT) were obtained. Macular complications, central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) were evaluated from OCT images. Ocular and surgical history and perioperative complications were also recorded. Uncorrected and best-corrected visual acuity (UCVA/BCVA) 1 month post-operatively and its influencing factors were evaluated. Results: The average AL of all involved eyes was 29.52 ± 2.26 mm, and 39.7% of which were with an AL > 30 mm and 26.4% of which were with a corneal astigmatism more than 1.5 D. Nuclear cataract accounted for the largest proportion (70.6%). The rate of overall macular complications was 27.6%. Postoperative UCVA and BCVA were 0.70 ± 0.46 and 0.25 ± 0.32 logMAR, respectively. BCVA improved significantly after surgery (vs. P < 0.001) and affected by the elongation of AL (P < 0.001) and thinning of CFT and SFCT (both P < 0.001). The risk factors of post-operative low vision (BCVA < 20/66) were macular atrophy, lamellar macular hole, high corneal astigmatism, long AL, thin SFCT and junior surgeons, odds ratios ranging from 1.54 to 54.87 (all P < 0.05). Conclusion: Cataract surgery could improve the VA of highly myopic eyes. Eye with macular complications, higher corneal astigmatism, longer AL, thinner SFCT, and who was treated by a junior surgeon, may have a high risk of low vision after surgery.