To evaluate safety and visual outcomes in surgically aphakic children undergoing secondary intraocular lens (IOL) implantation.
Retrospective, consecutive, interventional case series.
One hundred seventy-four eyes of 104 children (70 bilateral, 34 unilateral) who underwent secondary IOL implantation for aphakia after congenital cataract surgery at L. V. Prasad Eye Institute, Hyderabad, India, were analyzed. A minimum of 3 months of follow-up after surgery was required for inclusion in the study. Eyes with aphakia after surgery for traumatic cataracts and other associated ocular comorbidities were excluded. Main outcome measures were intraoperative and postoperative complications and visual outcome at the last follow-up.
Mean age at secondary IOL implantation was 6.08 ± 3.75 years. The mean follow-up was 25.7 ± 24.9 months. Mean best-corrected visual acuity improved from 1.08 ± 0.65 in aphakic children to 0.55 ± 0.51 logarithm of the minimal angle of resolution in pseudophakic children at last follow-up ( P < .0001). Overall, 51 eyes (35%) attained a final best-corrected visual acuity of 20/40 (0.3 logarithm of the minimal angle of resolution) or better, whereas only 2 eyes (8.7%) attained a final best-corrected visual acuity of 20/40 (0.3 logarithm of the minimal angle of resolution) or better in children who underwent secondary IOL implantation for unilateral aphakia. The most common postoperative complications were secondary membrane formation (17 eyes; 9.77%), optic capture (15 eyes; 8.6%), IOL decentration (9 eyes; 5.17%), and secondary glaucoma (11 eyes; 5%).
Secondary sulcus IOL implantation in children is a relatively safe procedure and leads to favorable visual postoperative outcomes.
Over the past decade, there has been a steady rise in the number of pediatric ophthalmologists preferring primary intraocular lens (IOL) implantation in children younger than 2 years undergoing cataract surgery. However, primary IOL implantation in children younger than 1 year remains controversial and widely debated. As a result, a significant number of surgeons still prefer aphakia as their initial management strategy in children younger than 1 year. Moreover, in children with associated microcornea, persistent fetal vasculature, rubella cataract, and so forth, it may be preferable to leave them aphakic at primary surgery. Early correction of aphakic refractive error is most critical component in management of such cases to prevent development of amblyopia and may be achieved by means of aphakic spectacle, contact lens, or secondary IOL. Secondary IOL implantation is considered when an aphakic child becomes intolerant to contact lenses or is noncompliant with spectacle wear. The additional economic burden and emotional turmoil of spectacle wear in a young child that the parents undergo makes rehabilitation of an aphakic child immensely challenging. Hence, the indications for a secondary IOL implantation also have come to include parental demand for an IOL because of their dissatisfaction with current method of optical rehabilitation.
Past studies have reported on the safety and favorable results with secondary IOL implantation. However, these studies have been limited by small sample size and the complication rates based on these small samples. Hence, the safety and efficacy of this procedure are not well studied. We undertook this study to evaluate the safety and visual outcomes after secondary IOL implantation in children for surgical aphakia after congenital cataract surgery in a large cohort.
This retrospective, consecutive, interventional case series chart review of patient data was approved by the Institutional Review Board of L. V. Prasad Eye Institute, Hyderabad, India. A retrospective chart review of children who underwent secondary IOL implantation between January 2000 and December 2010 for aphakia after congenital cataract surgery at a tertiary eye care centre in India was undertaken. Both unilateral and bilateral cases were included. A minimum of 3 months of follow-up after surgery was required for inclusion. Eyes with aphakia after surgery for traumatic cataracts; associated corneal pathologic features; associated pre-existing ocular comorbidities, such as aphakic glaucoma; microcornea; and retinal diseases like familial exudative vitreoretinopathy, retinopathy of prematurity, persistent foetal vasculature, and so forth were excluded. We also excluded cases with incomplete details pertaining to the primary diagnosis and postoperative complications. Indications for IOL implantation included 1 or more of the following: poor contact lens or aphakic spectacle compliance; contact lens intolerance; parental demand for IOL; or the treating ophthalmic surgeon advising a secondary IOL implantation to obtain more functional vision without additional optical correction.
The parameters studied were: patient age at the time of initial cataract surgery and secondary IOL implantation, patient demographic features, best-corrected visual acuity (BCVA; with aphakic glasses or contact lens) at presentation and final follow-up, and complications at each follow-up visit. Each child underwent a detailed dilated examination before surgery to evaluate adequate capsular support for posterior chamber IOL in the clinic or under anaesthesia. The surgical procedure and the postoperative care have been described elsewhere in a report published by our group.
The main outcome measures were intraoperative and postoperative (at each visit) complications and visual outcomes at the final follow-up. Occurrence of complications such as corneal edema, increased postoperative inflammation (>2+ cells or flare in the anterior chamber), glaucoma, retinal detachment, secondary membrane formation, wound leak, strabismus, IOL decentration, and endophthalmitis was noted. If the intraocular pressure was more than 22 mm Hg with increased optic nerve cupping (increase by 0.2 or more than previous visit or an asymmetric cupping of more than 0.2 in unilateral cases), myopic refractive shift beyond that expected (in children 8 years of age or younger), an increase in corneal diameter compared with the previous visit (in children younger than 4 years) occurred, or a combination thereof, then the patient was considered to have secondary glaucoma. IOL decentration was defined as the presence of the edge of the optic in the pupillary area in an undilated or dilated state. New-onset strabismus was defined as presence of deviation of more than 10 prism diopters on cover test at distance or near fixation that was not present before surgery. Visual outcome was assessed by changes in BCVA, which was measured with appropriate optical correction with the Snellen chart or LEA symbols (and then converted to Snellen equivalents) during each postoperative follow-up visit.
Descriptive and inferential statistics were performed using STATA for Windows version 12 (StataCorp LP, College Station, Texas, USA). The Wilcoxon signed-rank test was used to compare the BCVA before and after the surgical intervention. The Mann–Whitney U test was used to compare the improvement in BCVA between the bilateral and unilateral secondary IOL group. A P value of less than .05 was considered statistically significant.
During the study period, 174 eyes of 104 children (68 boys and 36 girls; male-to-female ratio, 1.9:1) underwent secondary IOL implantation at a mean age of 6.08 ± 3.75 years, at 5.6 ± 2.8 years after primary cataract surgery. Mean follow-up duration was 25.7 ± 25.0 months (range, 3 to 117 months; median, 18 months), with 31 eyes (18%) having a follow-up of between 3 and 6 months, 30 eyes (17%) eyes having a follow-up between 6 and 12 months, 49 eyes (28%) having a follow-up between 13 and 24 months, 41 eyes (23.5%) having a follow-up between 24 and 48 months, 7 eyes (4%) having a follow-up between 48 and 72 months, and 16 eyes (9%) having a follow-up between 72 and 120 months. Bilateral surgery was performed in 70 (67.3%) of 104 patients. Before surgery, visual axis opacification was noted in 10 eyes (4 unilateral and 6 bilateral), and an additional membranectomy was performed at the time of secondary IOL implantation. Nondilating and small pupil was noted during surgery in 3 eyes (unilateral group), each of which underwent an additional pupilloplasty at the time of secondary IOL implantation. Additional synechiolysis was performed in 6 eyes (1 unilateral, 5 bilateral) at the time of secondary IOL implantation.
Most children (n = 66; 63.5%) underwent secondary IOL implantation between 2 and 8 years of age ( Figure 1 ). In 41%, the operating surgeon advised secondary IOL implantation after discussing the benefits and drawbacks with the parents, ascertaining adequate capsular support, and ruling out any contraindications. Other indications included parental demand for more functional vision without additional optical correction (24%), contact lens noncompliance or intolerance (22%), and spectacle noncompliance (13%). Nystagmus was noted in 44 patients (42.3%) before surgery, and none of the patients had resolution of nystagmus after surgery. Strabismus was seen in 42 (40.38%) of the patients before surgery, and an additional 17 patients demonstrated strabismus after surgery. In-the-bag placement of the IOL was possible in only 2 of 174 eyes. A polymethyl methacrylate (PMMA) IOL was implanted in 81%, and the rest received 3-piece acrylic hydrophilic or hydrophobic IOLs. A scleral tunnel was constructed for IOL implantation in 66%, a clear corneal tunnel was constructed in 26.5%, and a limbal incision was made in the remaining 7.5%.
Preoperative and final visual acuity details were available in 144 (83%) of 174 eyes. The 30 eyes (11 unilateral and 19 eyes that underwent bilateral secondary IOL implantation) for which preoperative and postoperative BCVA measurements were not available were excluded from the analysis. Mean BCVA improved from 1.08 ± 0.65 logarithm of the minimal angle of resolution (logMAR) before surgery (in aphakic children) to 0.55 ± 0.51 logMAR after surgery (in pseudophakic children) at last follow-up, which was statistically significant ( P < .0001; Figure 2 ). Mean BCVA improved from 1.06 ± 0.77 logMAR before surgery to 0.44 ± 0.45 logMAR after surgery at last follow-up in children who underwent bilateral secondary IOL implantation ( P = .0000), and mean BCVA improved from 1.72 ± 1.18 logMAR before surgery to 0.83 ± 0.52 logMAR after surgery at last follow-up in children who underwent unilateral secondary IOL implantation ( P = .0012). The improvement in BCVA in the bilateral secondary IOL group was significantly higher compared with the unilateral secondary IOL group ( P = .0023; Figure 3 ). At the last follow-up, 51 eyes (35%) had a BCVA of 20/40 (0.3 logMAR) or better; 38 eyes (26%) had BCVA better than 20/100 (0.7 logMAR), but worse than 20/40; 29 eyes (20%) had a BCVA better than 20/200 (1.0 logMAR), but worse than 20/100; and 26 eyes (18%) had a BCVA worse than 20/200 ( Table 1 ). In children who underwent unilateral secondary IOL implantation, only 2 (8.7%) eyes attained a BCVA of 20/40 or better; 8 (35%) eyes had BCVA better than 20/100, but worse than 20/40; 7 (30%) eyes had a BCVA better than 20/200, but worse than 20/100; and 6 (26%) eyes had a BCVA worse than 20/200 at the final follow-up.
|Snellen BCVA (logMAR) at Last Follow-up||No. of Eyes (%)|
|20/40 (0.3) or better||51 (35.42)|
|Better than 20/100 (0.7) but worse than 20/40 (0.3)||38 (26.4)|
|Better than 20/200 (1.0) but worse than 20/100 (0.7)||29 (20.14)|
|Worse than 20/200 (1.0)||26 (18.05)|
The most common complications after surgery were secondary membrane formation (17 eyes; 10%), optic capture (15 eyes; 9%), IOL decentration (9 eyes; 5%), and glaucoma (11 eyes; 5%). Transient raise in intraocular pressure was seen in 5 eyes (2.87%). In 1 eye, the 3-piece acrylic hydrophobic IOL dislocated into the vitreous cavity 6 weeks after surgery. Postoperative hypotony developed in 12 (6.9%) eyes, of which 2 eyes had a wound leak ( Table 2 ).
|Complication||No. of Eyes (%)|
|Secondary membrane formation||17 (9.77)|
|New-onset strabismus||17 (9.77)|
|Optic capture||15 (8.6)|
|Postoperative hypotony||12 (6.9)|
|IOL decenteration||9 (5.17)|
|Transient IOP rise||5 (2.87)|
|Postoperative increased inflammation||4 (2.3)|
|Postoperative wound leak||2 (1.15)|
|Dislocation of IOL into vitreous||1 (0.57)|