Risk factors for lens dislocation post cataract surgery
Reviewed by Tasmin Berman

This retrospective cohort study in Korea assessed the risk factors for intraocular lens (IOL) dislocation. They used national data of 2,162,191 patients who had had cataract surgery between 2009 and 2016. They excluded any patient who had an IOL dislocation within one week of initial cataract surgery. They also excluded any patient younger than 40 at the time of surgery, with congenital eye disease such as Marfan syndrome, congenital cataracts and congenital anomalies. They found that IOL dislocation occurred in 15,170 (0.7%) of patients, more commonly in males compared to females (1:1.8) and with a peak incidence at 40-50 years. However, the mean age of IOL dislocation was 65.25 ±10.81 years and posterior capsulotomy performed within one year of cataract surgery significantly reduced the IOL dislocation rate with an adjusted Hazard ratio of 0.48 (p<0.0001; 95% CI 0.44-0.51). They also identified that the adjusted hazard ratio for IOL dislocation after partial vitrectomy was 11.93 (p<0.0001). They found that 10,784 patients had mild IOL dislocation and 4386 had more severe dislocation requiring surgery. In summary, they found that risk factors for dislocation were younger age, male sex, preoperative conditions of glaucoma, uveitis, pseudoexfoliation, traumatic cataracts and brunescent cataracts. Previous or concurrent vitrectomy, glaucoma or retinal surgery, iris and ciliary body injuries, uveitis corneal endothelial damage causing pseudophakic bullous keratopathy, and macular oedema requiring repeated intravitreal injections. This study found a higher incidence rate of dislocations than previous studies. They also found that a posterior capsulotomy was protective rather than a risk factor as discussed in previous studies. This study was a national study and therefore avoided selection bias and had a very large sample size meaning their results are representative for that population and reliable.

Risk factors for intraocular lens dislocation after phacoemulsification: a nationwide population-based cohort study.
Lee G, Lim D, Chi S, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2020;214:86-96.