Aphakia is caused due to many factors in children. This study examined factors such as congenital cataract, open-globe ocular trauma, and congenital anomalies such as ectopia lentis unlike other studies that focused on congenital cataracts, traumatic cataracts, or ectopia lentis (3-8). Here, we compared visual outcomes for all categories. The nontraumatic category exhibited more favorable outcomes possibly due to comorbidities in traumatic cases (p=0.004; Table ).
Secondary lens were implanted in different locations, namely the bag and sulcus; scleral-fixated and posterior chamber iris claw lens were implanted. No significant differences were observed (p=0.09).
According to Wood et al., secondary lens implanted in the capsular bag resulted in fewer complications than did those in the ciliary sulcus. Many patients recruited to this study received implants in the capsular bag (69.4%). This finding may be responsible for low complication rates and indicates that capsular bag preservation is crucial for secondary lens implantation. However, this finding limits the generalizability of study results to other centers where a higher proportion received implants in the bag and sulcus (18).
The major complication or cause of nonimprovement of vision in this study was corneal opacity (12/84 patients, 14.29%, Table). A study reported VAO, secondary glaucoma, and refractive problem as causes in 5.4%, 16.4%, and 8.1% of patients, respectively. The current study included many (32/84) posttrauma cases causing corneal opacities (Table) (18).
The mean ages during secondary lens implantation were 94.56 ± 72.84, 55.2 ± 21.6, and 46.64 ± 29.37 months in our study, Wood et al.’s study, and Rong et al.’s study, respectively (18,19). This might be attributed to the lack of awareness in rural areas and ignorant parents. Owing to the low socioeconomic status, compliance of aphakic spectacles and contact lenses is poor, thus affecting the outcome because of amblyopia. The mean follow-up period was 3.53 ± 5.6 years in this study, 57.6 ± 33.6 months in Woods et al.’s study, and 109.09 ± 18.89 months in Rong et al.’s study, respectively. This difference can be due to variations in sociodemographic factors.
Furthermore, 42 (50%) and 12 (14.3%) of 84 (50%) patients achieved visual acuities of >6/24 and <1/60, respectively.
The median visual acuities reported by Woods et al. and Rong et al. at the final visit were 20/40 and 6/18, respectively. These results are similar to those reported by previous studies (16,17) including that conducted by Nihalani and Vanderveen (14) who demonstrated that 50% eyes had a BCVA of ≥20/40 and Shenoy et al. who found that 35% eyes had a BCVA of ≥20/40 (20).
Hu et al. demonstrated that secondary iris claw lens implantation resulted in satisfactory vision (21). Forlini indicated that retro pupillary iris claw lens is a suitable option for scleral-fixated or angle-supported lens (22). Retropupillary iris claw lens implantation can safely and effectively correct aphakia without capsule support (23,24).
He et al indicated that secondary lens implants can safely correct aphakia in for open-globe injury patients undergoing vitrectomy. This finding is in agreement with that of this study; we noted no differences in outcomes among various lens positions (25).
Secondary sulcus IOL could be implanted after preserving the anterior lens capsule during primary implantation in children with anterior PFV; this procedure resulted in favorable vision outcomes after operation and a compatible proportion of complications (26-28).
Yu and Maxwell observed favorable longer-term findings and few complications after sutured scleral-fixated foldable lens implantation. Their procedure is safe, does not need complex equipment, and can correct aphakia in the absence of adequate capsule support (29,30).
Edelstein S reported successful outcomes of scleral-fixated lens implants in congenital ectopia lentis, which is similar to this study (31).
This study compared the outcomes of various lens positions in different etiologies and exhibited no significant differences.
A strength of the present study is that the same surgeon operated all eyes. The study is limited by its retrospective nature; however, incomplete records were excluded. Future studies should include more patients and examine different postoperative complications. In addition, because young patients were enrolled, we could not perform BCVA Snellen measurements. A more standardized method for measuring visual acuity can be beneficial.