Despite improvements in pediatric cataract surgery techniques, better instrumentation, and better intraocular lenses (IOLs), posterior capsule opacification (PCO) remains the most frequent complication following pediatric cataract surgery and, if not treated, may cause visual deprivation amblyopia. The reported incidence of PCO development in infants is up to 100% if the posterior capsule is left intact.1
Primary posterior capsulotomy with anterior vitrectomy (PPC+AV) along with cataract extraction is effective in preventing PCO.2 The main treatment option available for PCO is Nd:YAG laser capsulotomy.3,4 Patients who are not suitable for laser therapy such as small or uncooperative children, children with poor fixation, and patients who had nystagmus surgical membranectomy with anterior vitrectomy can have surgery via either a limbal or pars plana approach to remove PCO. In cases of thick PCO, membranectomy combined with anterior vitrectomy is required, even in older children.5,6
There have been several studies on pars plana membranectomy or capsulovitrectomy via the pars plana route, but no exclusive study on limbal membranectomy.5–7 Xie et al.8 evaluated the outcome of pars plana capsulotomy with vitrectomy with infusion through the limbus to remove PCO in 51 children in whom Nd:YAG capsulotomy was difficult. They were able to remove the central opaque posterior capsule and anterior vitreous in all patients without any complications.
We have removed PCO via a limbal approach with both an infusion cannula and vitrector entering the anterior chamber through the limbus. The aim of this study was to evaluate the characteristics of children who required surgical membranectomy for PCO and its postoperative visual outcome and complications, if any. We have also highlighted the role of posterior optic buttonholing of the IOL during membranectomy.
Patients and Methods
After obtaining ethical approval from the institutional ethical committee, the medical records of all children younger than 17 years who underwent surgical membranectomy with anterior vitrectomy via a limbal approach for pediatric cataract at a tertiary eye care center over a period of 5 years from January 2014 to December 2018 were analyzed retrospectively. The study complied with the guidelines of the Declaration of Helsinki. Children with corneal scar, central media opacity other than PCO obscuring the visual axis, retinal and optic nerve pathology, and less than 6 months of follow-up after membranectomy were excluded from the study.
Demographic data and type of primary index surgeries were recorded, which included etiology of cataract, time lag between index surgery and PCO formation, whether PPC+AV was done or not as primary surgery, type and brand of IOL, location of implanted IOL, and any intraoperative and postoperative complications during primary surgery. All of the patients underwent detailed preoperative evaluation including slit-lamp examination and B- scan ultrasonography to rule out any retinal pathology. Biometries were performed in all cases in either aphakic or pseudophakic mode to calculate IOL power. Preoperative and postoperative best corrected visual acuity was recorded using an age-specific vision chart. We also assessed the time lag for PCO formation after cataract surgery. All young children not suitable for Nd:YAG capsulotomy underwent surgical membranectomy. Children who were refractory to laser treatment because of a thick membrane also underwent surgical membranectomy with a vitrector through a limbal approach.
Two side ports were created at the 10- and 2-o'clock positions at the limbus and the anterior chamber was accessed. Posterior synechiae were released with an iris repositor under viscoelastic, the membrane/PCO was nicked with a microvitreoretinal blade, and the opening was enlarged to 4 to 5 mm with a vitrector using the bimanual 23-gauge vitrector of the Alcon INFINITI system (Alcon Laboratories, Inc., Fort Worth, TX). The membrane was approached by tilting the IOL in cases of pseudophakia. After completion of membranectomy in aphakic children, a 3.2-mm superior clear corneal incision was made and a secondary IOL (three-piece hydrophobic IOL) was implanted in the sulcus with posterior optic buttonholing. The side port incision and clear corneal incision were sutured with 10-0 polyglactin 910. At the end of surgery, intracameral moxifloxacin injection was given and the wound was hydrated. Any adverse events during surgery (eg, broken haptic, IOL drop, or IOL exchange) were noted, and the rate of successful completion of membranectomy was analyzed.
Postoperative follow-up was done at 1 day, 1 week, and 1, 3, and 6 months. Any postoperative complications, improvement in visual acuity, IOL centration, and intraocular pressure rise were assessed.
Statistical analysis was performed using SPSS software (version 20; SPSS, Inc., Chicago, IL). Quantitative variables were reported as mean ± standard deviation. The t test was used for analysis of quantitative data. A P value of less than .05 was considered significant.
A total of 60 eyes of 58 children who met the inclusion criteria were included in the study. Two children presented with bilateral thick PCO, and the remaining were unilateral. All children had best corrected visual acuity of worse than 6/60 at the time of presentation. There were 35 boys and 23 girls. The mean age of the children was 113.43 ± 64.835 months (range: 3 to 204 months). Of 60 eyes with PCO, 26 had traumatic etiology and 34 had developmental cataract. The mean time duration for PCO formation was 27.83 ± 39.83 months for traumatic cases and 53.53 ± 52.20 months for developmental cataract (P = .04). In developmental cataract, PCO formed earlier in the cases where PPC+AV was not done as the primary procedure (P = .02). However, no significant difference was seen in traumatic cataract with or without PPC (P = .11). Table 1 shows the demographic profile and preoperative characteristics of the children.
Preoperative Characteristics of Children Who Underwent Surgical Membranectomy
Complications and Success of Membranectomy
A satisfactory opening in the center of the membrane was achieved in 47 cases (78.33%). In 13 cases, we were unable to approach the thick membrane through a limbal approach because of dense adhesion between the IOL and anterior capsulorhexis. These children underwent pars plana membranectomy in the same sitting. There was no closure or visual axis obscuration of the central opening during the 6-month follow-up. However, in one case, the clear central opening was only approximately 2.5 mm. All children who needed the pars plana approach had in-the-bag hydrophobic IOLs.
The most common complications on day 1 were mild to moderate uveitis in 5 eyes and corneal edema in 3 eyes, which resolved by subsequent follow-up at 1 month with topical steroids and mydriatics. Two eyes had pigment deposition over the IOL in which the IOL was in the sulcus without posterior optic buttonholing. A single case had raised intraocular pressure after mebranectomy, which was probably steroid dependent and was managed medically. One case of IOL drop occurred after membranectomy in an operated cataract with PPC. IOL exchange was done in one case because the multipiece IOL haptic broke during synechiolysis.
Role of Posterior Optic Buttonholing During Membranectomy
Nine patients who underwent membranectomy were aphakic and the three-piece sulcus IOL was implanted with posterior optic buttonholing. Membranectomy with posterior optic buttonholing of the IOL resulted in good IOL centration, no anterior chamber reaction, and no iris optic capture in the postoperative period.
In pseudophakic children, a sulcus-fixated IOL was found in 21 children, with 2 having optic capture and 7 having decentered IOL; most of them were of traumatic etiology. After completion of adequate membranectomy, posterior optic buttonholing was tried in these cases, in which success was achieved in 7 cases only.
Visual Outcome After Membranectomy
Mean visual acuity improved from 1.16 ± 0.52 logMAR (range: 0.18 to 1.78 logMAR) before membranectomy to 0.73 ± 0.55 logMAR (range: 0 to 1.78 logMAR) after membranectomy, which was statistically significant (P < .001). For aphakia, visual acuity after membranectomy and IOL placement improved from 1.352 ± 0.464 (range: 0.48 to 1.78) to 0.838 ± 0.494 (range: 0.30 to 1.78) (P = .027). For pseudophakia, visual acuity improved from 0.951 ± 0.499 (range: 0.18 to 1.78) to 0.4966 ± 0.549 (range: 0 to 1.48) (P < .001).
PCO or membrane formation is one of the most common complications following cataract surgery. Proliferation and migration of residual lens epithelial cells in the capsular bag have been implicated in the pathogenesis of PCO.9 Buckley et al.1 reported that the incidence of PCO is high in children because of the greater tissue reactivity of lens epithelial cells. The rate of PCO formation is up to 100% when the posterior capsule remains intact. In our series of 60 eyes, 33 had not undergone PPC as the primary procedure. The rate of PCO formation is faster in cases in which PPC has not been done, but this difference was statistically significant for developmental cataract only in our study (P = .02).
Eyes with traumatic cataract were more likely to develop PCO than eyes without traumatic cataract. Trivedi et al.10 also reported that PCO develops faster in eyes with traumatic cataract. PCO formed earlier in traumatic cataract compared to developmental cataract in our study (P = .04).
Vilhjalmsson and Lucas11 evaluated the incidence of PCO in the capsular bag versus sulcus fixation of posterior chamber IOLs. They found that the incidence of PCO was 14% in eyes with capsular bag implantation as opposed to 20% with sulcus fixation. In our study, 21 eyes had sulcus-fixated IOLs. Gimbel and DeBroff12 reported that posterior continuous curvilinear capsulorhexis with optic capture of the IOL was successful in preventing secondary opacification of the visual axis in pediatric cataract cases. In our series, none of the children who underwent membranectomy had posterior optic buttonholing as the primary surgery.
Management of dense or thick PCO after cataract surgery through the pars plana approach is the standard of care. Pars plana membranectomy has also been advocated for secondary membranes thicker than 1.2 mm and even for thinner membranes in young, uncooperative children not suitable for YAG capsulotomy.13 Performing pars plana membranectomy for PCO has some disadvantages. These include the requirement of skill for making the pars plana port on the part of the surgeon and higher rates of cystoid macular edema, retinal hole formation, and retinal detachment.14 To shorten the surgical time and complications of pars plana membranectomy, Xie et al.8 recommended pars plana capsulotomy with a vitrector and infusion through the limbus. Even so, this technique needs one pars plana port for the vitrector.
Our technique is simpler than the abovementioned technique because both the vitrector and infusion entered through the limbus. We were able to make a satisfactory opening in the center of the membrane in 78.3% of cases through the limbal approach. Our success rate is better than those of other studies that performed pars plana membranectomy.7,8,15 There was no closure or visual axis obscuration of the central opening during the 6-month follow-up in our series, as has been observed by Laiesegang et al.16
A total of 29 IOLs were positioned in the bag in our series. We were unable to approach the membrane in 13 cases by tilting the IOL because PCO and capsular fibrosis occurred early in these eyes and formed tight adhesions and a thickened capsule. However, we were able to complete membranectomy in other in-the-bag IOL cases because they had either a larger anterior rhexis on one side or hydrophilic IOLs with less adhesion.
The common complications we encountered were mild to moderate uveitis in 5 eyes and corneal edema in 3 eyes. Complications such as anterior chamber reaction and corneal edema are also common after pars plana membranectomy.13 More cases of corneal edema in our study might be due to irrigating solution near the endothelium responsible for its altered function. Two eyes had pigment deposition over the IOL in our study. The incidence of IOL surface deposits after pediatric cataract surgery ranged from 0% to 100% in different studies.17,18 One case had raised intraocular pressure after mebranectomy in our study similar to Juarez et al.,19 who reported a transient increase in intraocular pressure but could not describe any reason for it. Our case was probably a steroid responder and was managed medically. Two cases had IOL-related complications (one broken haptic and one dislocated lens), which is more than the pars plana approach and may be because of difficulty in manipulating the cutter behind the IOL. In the single dislocated IOL case, pars plana vitrectomy with IOL removal was done and breaks were treated with laser. A scleral-fixated IOL was placed later. No other posterior segment complications were noted after membranectomy with posterior optic buttonholing, which is similar to the findings of Menapace.20,21 There was posterior synechia with IOL decentration in one case of developmental cataract in which a three-piece IOL haptic broke during synechiolysis. IOL exchange with a three-piece IOL along with posterior optic buttonholing was done in that case.
We have done secondary IOL implantation in 9 aphakic patients following membranectomy, in which the three-piece sulcus IOL was implanted with posterior optic buttonholing. Posterior chamber IOL implantation into the capsular bag is always preferred in pediatric cataract surgery22; however, in secondary IOL implantation it is difficult to open the capsular bag23 so we implanted the IOL in the sulcus. Fixation of IOLs in the ciliary sulcus increases IOL malposition and crowding of the anterior segment in pediatric eyes.24 Zhou and Zhou25 published a meta-analysis of 282 eyes with pediatric cataracts that had posterior optic buttonholing and showed that the technique can significantly reduce the eccentricity of the IOL. Vasavada et al.26 demonstrated that the posterior optic buttonholing technique provides stability and long-term centration of the IOL. In all cases of posterior optic buttonholing in our study, the IOL was well centered postoperatively at 6 months of follow-up. None of these patients developed iris optic capture. The posterior optic buttonholing technique of the IOL ensures that the anterior and posterior capsule are closely in contact and on the front surface of the IOL, which greatly reduces the risk for pupil capture.
We achieved significant visual acuity improvement after membranectomy. Mean visual acuity improved from 1.16 ± 0.52 to 0.73 ± 0.55 logMAR (P < .001). Our findings were similar to those of Wasserman et al.27 and Lam et al.7 Of 60 eyes that underwent membranectomy, 48 eyes (80%) showed improvement in visual acuity, which is comparable to the studies of Cinal et al.3 and Atkinson and Hiles4 in which 73% and 76% of eyes, respectively, showed improvement in visual acuity after Nd:YAG capsulotomy. The lack of improvement in visual acuity in the remaining eyes may be attributed to amblyopia or traumatic anterior and posterior segment pathologies in our study.
Although we have described an easier approach of surgical membranectomy with its outcomes, this study had its own limitations because of its retrospective nature, small sample size, shorter follow-up, and lack of a control group for comparisons with the pars plana approach. We have also not considered amblyopia, strabismus, and nystagmus in the analysis of visual outcome. Thickness of membrane, size of anterior rhexis, extent of posterior synechia, and ease of manipulation during membranectomy should also be evaluated in a future study. In-the-bag IOL placement should be evaluated separately because most of our failures occurred in this group only.
Surgical membranectomy with a vitrector via a limbal approach is a safe and effective method for managing PCO after cataract membrane in the pediatric population, resulting in good visual outcome. Posterior optic buttonholing of the IOL during membranectomy or secondary IOL implantation results in good IOL centration and fewer complications.
- Buckley EG, Klombers LA, Seaber JH, Scalise-Gordy A, Minzter R. Management of the posterior capsule during pediatric intraocular lens implantation. Am J Ophthalmol. 1993;115(6):722–728. doi:10.1016/S0002-9394(14)73638-4 [CrossRef]
- Spierer A, Desatnik H, Blumenthal M. Refractive status in children after long-term follow up of cataract surgery with intraocular lens implantation. J Pediatr Ophthalmol Strabismus. 1999;36(1):25–29.
- Cinal A, Demirok A, Yasar T, Yazicioglu A, Yener HI, Kiliç A. Nd:YAG laser posterior capsulotomy after pediatric and adult cataract surgery. Ann Ophthalmol (Skokie). 2007;39(4):321–326. doi:10.1007/s12009-007-9005-0 [CrossRef]
- Atkinson CS, Hiles DA. Treatment of secondary posterior capsular membranes with the Nd:YAG laser in a pediatric population. Am J Ophthalmol. 1994;118(4):496–501. doi:10.1016/S0002-9394(14)75802-7 [CrossRef]
- Xie L, Huang Y. Pars plana capsulectomy and vitrectomy for posterior capsular opacification in pseudophakic children. J Pediatr Ophthalmol Strabismus. 2008;45(6):362–365. doi:10.3928/01913913-20081101-16 [CrossRef]
- Srinivasan S, Koshy Z. Pars plana posterior capsulectomy with a 27-gauge microincision vitrectomy system for dense posterior capsule opacification. J Cataract Refract Surg. 2017;43(6):719–723. doi:10.1016/j.jcrs.2017.05.019 [CrossRef]
- Lam DS, Fan DS, Mohamed S, Yu CB, Zhang SB, Chen WQ. 25-gauge transconjunctival sutureless vitrectomy system in the surgical management of children with posterior capsular opacification. Clin Exp Ophthalmol. 2005;33(5):495–498. doi:10.1111/j.1442-9071.2005.01068.x [CrossRef]
- Xie LX, Zhang WB, Huang YS. [The surgical treatment for posterior capsule opacification in children with pseudophakic eyes]. Zhonghua Yan Ke Za Zhi. 2005;41(6):511–514.
- Apple DJ, Solomon KD, Tetz MR, et al. Posterior capsule opacification. Surv Ophthalmol. 1992;37(2):73–116. doi:10.1016/0039-6257(92)90073-3 [CrossRef]
- Trivedi RH, Wilson ME Jr, Bartholomew LR, Lal G, Peterseim MM. Opacification of the visual axis after cataract surgery and single acrylic intraocular lens implantation in the first year of life. J AAPOS. 2004;8(2):156–164. doi:10.1016/j.jaapos.2003.10.008 [CrossRef]
- Vilhjalmsson GA, Lucas BC. [Incidence of secondary cataract in sulcus versus capsular bag fixation of posterior chamber lenses]. Klin Monatsbl Augenheilkd. 1992;200(3):167–170. doi:10.1055/s-2008-1045731 [CrossRef]
- Gimbel HV, DeBroff BM. Posterior capsulorhexis with optic capture: maintaining a clear visual axis after pediatric cataract surgery. J Cataract Refract Surg. 1994;20(6):658–664. doi:10.1016/S0886-3350(13)80659-1 [CrossRef]
- Angra SK, Rai CB, Kalra VK. Management of secondary pupillary membrane in aphakia (YAG discussion vs pars plana membranectomy). Indian J Ophthalmol. 1991;39(4):154–158.
- Alexandrakis G, Peterseim MM, Wilson ME. Clinical outcomes of pars plana capsulotomy with anterior vitrectomy in pediatric cataract surgery. J AAPOS. 2002;6(3):163–167. doi:10.1067/mpa.2002.122148 [CrossRef]
- Mitra S, Ganesh A. Pars plana capsulovitrectomy for posterior capsular opacification in children. Ophthalmic Surg Lasers Imaging. 2003;34(4):327–331.
- Liesegang TJ, Bourne WM, Ilstrup DM. Secondary surgical and neodymium-YAG laser discussions. Am J Ophthalmol. 1985;100(4):510–519. doi:10.1016/0002-9394(85)90672-5 [CrossRef]
- Faramarzi A, Javadi MA. Comparison of 2 techniques of intraocular lens implantation in pediatric cataract surgery. J Cataract Refract Surg. 2009;35(6):1040–1045. doi:10.1016/j.jcrs.2009.02.017 [CrossRef]
- Raina UK, Mehta DK, Monga S, Arora R. Functional outcomes of acrylic intraocular lenses in pediatric cataract surgery. J Cataract Refract Surg. 2004;30(5):1082–1091. doi:10.1016/j.jcrs.2003.11.027 [CrossRef]
- Juarez CP, Peyman GA, Raichand M, Goldberg MF. Secondary pupillary membranes treated by the pars plana/pars plicata approach: long-term results of 108 cases. Br J Ophthalmol. 1981;65(11):762–766. doi:10.1136/bjo.65.11.762 [CrossRef]
- Menapace R. Routine posterior optic buttonholing for eradication of posterior capsule opacification in adults: report of 500 consecutive cases. J Cataract Refract Surg. 2006;32(6):929–943. doi:10.1016/j.jcrs.2006.02.046 [CrossRef]
- Menapace R. Posterior capsulorhexis combined with optic buttonholing: an alternative to standard in-the-bag implantation of sharp-edged intraocular lenses? A critical analysis of 1000 consecutive cases. Graefes Arch Clin Exp Ophthalmol. 2008;246(6):787–801. doi:10.1007/s00417-008-0779-6 [CrossRef]
- Brady KM, Atkinson CS, Kilty LA, Hiles DA. Cataract surgery and intraocular lens implantation in children. Am J Ophthalmol. 1995;120(1):1–9. doi:10.1016/S0002-9394(14)73753-5 [CrossRef]
- Nihalani BR, Vanderveen DK. Secondary intraocular lens implantation after pediatric aphakia. J AAPOS. 2011;15(5):435–440. doi:10.1016/j.jaapos.2011.05.019 [CrossRef]
- Zhao YE, Gong XH, Zhu XN, et al. Long-term outcomes of ciliary sulcus versus capsular bag fixation of intraocular lenses in children: an ultrasound biomicroscopy study. PLoS One. 2017;12(3):e0172979. doi:10.1371/journal.pone.0172979 [CrossRef]
- Zhou HW, Zhou F. A meta-analysis on the clinical efficacy and safety of optic capture in pediatric cataract surgery. Int J Ophthalmol. 2016;9(4):590–596.
- Vasavada AR, Vasavada V, Shah SK, et al. Postoperative outcomes of intraocular lens implantation in the bag versus posterior optic capture in pediatric cataract surgery. J Cataract Refract Surg. 2017;43(9):1177–1183. doi:10.1016/j.jcrs.2017.07.022 [CrossRef]
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Preoperative Characteristics of Children Who Underwent Surgical Membranectomy
|Characteristic||Developmental Cataract||Traumatic Cataract||Total|
|Mean age of surgery, mean ± SD (range), months||111.65 ± 70.05 (3 to 192)||115.77 ± 57.23 (10 to 204)||113.43 ± 64.835 (3 to 204)|
|Time duration for PCO formation, mean ± SD, months||53.53 ± 52.20||27.83 ± 39.83|
|IOL status, no.|
|IOL type (after primary surgery), no.|
| Hydrophobic IOL single-piece||19||8||27|
| Hydrophobic IOL three-piece||12||9||21|
| Hydrophilic IOL||2||0||2|
| PMMA lens||0||0||0|
|IOL location, no.|
| In the bag||21||8||29|
| In the sulcus||12||9||21|
| With iris optic capture||2||7||9|
|Primary surgical procedure, no.|
| Without PPC+AV||18||15||33|