Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Primary capsulectomy, anterior vitrectomy, lensectomy, and posterior chamber lens implantation in children: Limbal versus pars plana Hamid Ahmadieh, MD, Mohammad Ali Javadi, MD, Mandana Ahmady, MD, Farid Karimian, MD, Bahram Einollahi, MD, Mohammad Zare, MD, Mohammad Hosein Dehghan, MD, Arman Mashyekhi, MD, Naser Valaei, MS, Masoud Soheilian, MD, Hamid Sajjadi, MD ABSTRACT Purpose: To compare the results of a limbal versus a pars plana approach for primary posterior capsulectomy and anterior vitrectomy in the management of childhood cataract. Setting: Department of Ophthalmology, Labbafinejad Medical Center, Tehran, Iran. Methods: A randomized, controlled, double-masked clinical trial of 45 eyes was conducted. After being matched, 38 eyes were included in the study and were divided into 2 equal groups for data analysis. All eyes had lensectomy and posterior chamber intraocular lens (PC IOL) implantation. Primary posterior capsulectomy and anterior vitrectomy were performed through the limbus in half of the eyes and the pars plana in the other half. Main outcome measures included visual acuity, estimated red reflex, postsurgical inflammatory reaction, corneal clarity, posterior synechias, iris capture, IOL position, capsulectomy size, glaucoma, cystoid macular edema, retinal tear, and postoperative refraction. Results: No statistically significant differences were found between the 2 approaches in the outcome measures. Conclusion: The anatomic and visual results were encouraging when posterior capsulectomy and anterior vitrectomy, using a limbal or pars plana approach, were combined with lensectomy and PC IOL implantation in children. The application of these techniques depends on surgeon experience and skill. J Cataract Refract Surg 1999; 25:768 –775 © 1999 ASCRS and ESCRS A mblyopia is the most common cause of impaired vision in children, and childhood cataract is a significant cause of it. Correction of aphakia and visual rehabilitation are important steps in the management of childhood cataract. © 1999 ASCRS and ESCRS Published by Elsevier Science Inc. Many surgeons implant a posterior chamber intraocular lens (PC IOL) to correct aphakia in children.1– 8 This method is especially useful in unilateral cases. Posterior capsule opacification (PCO), if the capsule remains intact, occurs in 51% to 100% of cases in 0886-3350/99/$–see front matter PII S0886-3350(99)00040-1 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT pediatric cataract surgery and prevents visual rehabilitation.3–5,9 –11 A neodymium:YAG (Nd:YAG) capsulotomy does not provide a long-lasting clear visual axis because the anterior hyaloid face acts as a scaffold for the growth of lens epithelial cells (LECs).12,13 The transformation of residual LECs results in dense membranes on the anterior hyaloid surface, visual axis reocclusion, haptic displacement, and iris capture.12–14 To provide better conditions for visual rehabilitation, primary posterior capsulotomy and anterior vitrectomy have been recommended.3,5,7,15,16 There are 2 approaches to primary posterior capsulectomy and anterior vitrectomy: through the limbus3,7 and through the pars plana.5 We conducted a clinical trial to compare the results of these 2 approaches. Patients and Methods A sequential, matched, randomized, doublemasked clinical trial was performed. The indications for cataract surgery in children were defined as any lens opacity that caused decreased visual acuity (20/60 or worse), stereopsis disturbance, deviation of the eyes, or all 3. The eyes were randomly assigned to be operated on using Technique A (limbal approach) or Technique B (pars plana approach). Cases of developmental cataract were subdivided into 2 groups: (1) zonular cataract; (2) other variations of developmental cataract. Cases of traumatic cataract were also subdivided into 2 groups: (1) associated with corneal laceration; (2) unassociated with corneal damage. In cases of bilateral developmental cataract, each eye was the control of the fellow eye. The randomization schedule determined which technique was to be used in the first eye having surgery. In unilateral cases, a randomization schedule also determined the approach. Accepted for publication January 26, 1999. From Labbafinejad Medical Center, Shaheed Beheshti University of Medical Sciences, Tehran, Iran. Presented in part at the annual meeting of the American Academy of Ophthalmology, Chicago, Illinois, USA, October 1996. None of the authors has a proprietary interest in any material used. Reprint requests to Hamid Ahmadieh, MD, Labbafinejad Medical Center, Pasdaran Avenue, Boostan 9 Street, Tehran 16666, Iran. Four statistical frames were prepared: (1) traumatic cataract without corneal damage; (2) traumatic cataract with corneal damage; (3) developmental cataract of zonular type; (4) developmental cataract of other types. The eligible cases were entered sequentially in related frames according to the type of cataract and the results of randomization. Cases of bilateral or unilateral developmental cataract or traumatic cataract were sequentially included in the study. The indication for cataract surgery was approved by at least 2 physicians independently. The minimum age was 3 years in unilateral cases and 5 years in bilateral cases. The maximum age was 10 years in both unilateral and bilateral cases. Traumatic cases with a history of surgery other than primary repair and cases with ocular hypotony were excluded. Eyes with scleral laceration, vitreous prolapse into the anterior chamber, signs of endophthalmitis and intraocular foreign bodies, or cataract associated with ocular or systemic disease were excluded. The presence of posterior synechias did not result in exclusion. An A-scan was used for PC IOL power calculation to achieve emmetropia postoperatively. The refraction in the fellow eye was considered, and anisometropia of more than 3.0 diopters (D) was avoided. The PC IOL type was identical in all cases: single-piece poly(methyl methacrylate). Surgical Technique All cases were operated on using general anesthesia and were performed by 1 of 3 surgeons (M.A.J., B.E., F.K.). Mydriatic drops, instilled before surgery, included tropicamide 1% (3 times) and phenylephrine 2.5% to 5% (1 time). A fornix-based peritomy was done and a 100 degree midlimbal groove made. Two stab incisions were created 120 to 150 degrees apart. An anterior capsulotomy was made with a needle and enlarged to 6.0 mm with a vitrectomy probe. Lens material was aspirated. This part of the procedure was similar in all cases, but the surgery then continued differently based on the technique used. Technique A. Posterior capsulotomy was done with a 23 gauge needle and then enlarged to 3.0 to 4.0 mm with a vitrectomy probe. An anterior vitrectomy was done through the posterior capsulotomy site. It was confirmed that no vitreous was present at the level of the pupillary area. Then, a limbal groove was opened into J CATARACT REFRACT SURG—VOL 25, JUNE 1999 769 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT the anterior chamber with corneal scissors. After injection of a viscoelastic material, the IOL was implanted in the capsular bag. Peripheral iridectomy was done, and the wound was closed with interrupted 10-0 nylon sutures. Technique B. The limbal groove was opened into the anterior chamber with corneal scissors. After injection of a viscoelastic material, the IOL was implanted in the capsular bag. The wound was temporarily closed with 3 separate 8-0 silk X-sutures. A sclerotomy was made 2.5 mm from the limbus in 1 superior quadrant. The infusion cannula was placed in the anterior chamber and the vitrectomy probe in the anterior vitreous cavity. A 3.0 to 4.0 mm posterior capsulectomy was made and an anterior vitrectomy performed, after which the sclerotomy site was repaired with a 7-0 polyglactin (Vicrylt) X-suture. The temporary X-sutures of the cataract wound were removed, a peripheral iridectomy was done, and the wound was closed with interrupted 10-0 nylon sutures. In all cases, a subconjunctival injection of 20 mg of gentamicin and 4 mg of betamethasone and a sub-Tenon’s injection of methylprednisolone acetate 20 mg were given. Follow-up, which was 1 year, was done by 1 physician who was masked to the surgical technique used. Written consent was obtained from all patients before enrollment, but they too were masked concerning technique. Follow-up forms were completed 1 and 3 days, 1, 3, and 6 weeks, 3 and 6 months, and 1 year after surgery. The type and dosage of postoperative medications, especially the frequency of topical steroids and necessity for systemic steroids, depended on the degree of inflammatory reaction in each eye. Medications on the first postoperative day were a betamethasone drop every 1 to 4 hours according to the severity of inflammation, sulfacetamide 10% every 6 hours, short-acting mydriatics if needed, and oral prednisolone if needed (1 mg/kg a day). In all cases, fluorescein angioscopy was performed using general anesthesia 4 to 6 weeks after surgery by 2 physicians (M.H.D., A.M.) masked as to surgical technique. An intravenous injection of 5 cc fluorescein sodium 10% was given. Indirect ophthalmoscopy was performed with a blue filter and a 20.0 D lens. Fundoscopy and refraction were done during the same session. Suture removal was performed according to the results of refraction and keratometry. 770 Eyes were classified according to the visual acuity: (1) light perception (LP)/hand movement (HM); (2) finger counting (CF); (3) 20/200 to 20/120; (4) 20/80 to 20/40; (5) 20/30 or better. Changes in visual acuity were evaluated by comparing preoperative and postoperative visual acuities, with the difference determined by the degree of visual acuity improvement postoperatively, which was shown by a plus (1) sign. For example, a preoperative visual acuity of HM changing to postoperative acuity of CF was a 11 improvement and preoperative visual acuity of HM changing to postoperative acuity of 20/120 was a 12 improvement. Thus, the range of improvement was 11 to 14. Eyes were also classified according to the estimated red reflex: (1) LP or HM; (2) CF; (3) 20/200 to 20/50; (4) 20/40 to 20/25; (5) 20/25 or better. The estimated postoperative red reflex was compared with the estimated preoperative red reflex, and the difference determined the degree of improvement. Improvement in postoperative red reflex was shown as a plus sign in the same manner as the visual acuity evaluation. Amblyopia Therapy Occlusion therapy was used to treat amblyopia. Therapy began before the surgery if possible. If not, it started within 1 week after surgery. Therapy comprised 1 week per 1 year of age of full-time patching followed by maintenance therapy. Every 3 months, full-time patching was repeated on the same schedule according to patient response. Results The study included 45 eyes of 31 patients, 14 of whom had bilateral surgery. In the other 17 patients, the cataract was unilateral, or if bilateral, surgery was indicated in 1 eye only. Mean patient age was 6.3 years 6 2 (SD). A t test showed no statistically significant difference between the 2 groups in age. Nineteen patients were girls. Chi-square analysis showed no significant difference between the 2 groups in sex. Of the 45 eyes, 39 eyes of 25 patients had developmental cataract and 6 patients had unilateral traumatic cataracts. Of 39 eyes with developmental cataract, 20 had zonular cataract. All traumatic cataracts were associated with corneal damage. Repair of corneal laceration J CATARACT REFRACT SURG—VOL 25, JUNE 1999 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT was not required in 2 eyes because the small laceration self-sealed. The interval between primary repair of corneal laceration and lensectomy was 3 to 6 weeks except in 1 case with an intumescent lens, in which cataract surgery was done 10 days after corneal laceration repair. Of 45 eyes, 2 (1 each in Techniques A and B) were excluded because of postoperative trauma necessitating deep vitrectomy and IOL removal. Five patients were excluded for inadequate follow-up. Distribution of the remaining 38 cases was as follows: 20 eyes with developmental cataract of zonular type, 14 with developmental cataract of other types, and 4 with traumatic cataract associated with corneal laceration (Table 1). The 38 matched cases were compared according to visual acuity and estimated red reflex before and after surgery, postoperative intraocular inflammation (fibrin formation in the anterior chamber), posterior synechias, IOL position, corneal status, glaucoma, cystoid macular edema (CME), anterior vitrectomy and posterior capsu- Table 1. Distribution of matched cases by technique, number (%). Type of Cataract Developmental Traumatic Technique Zonular Nonzonular With Corneal Damage Limbal 10 (52.7) 7 (36.8) 2 (10.5) Pars plana 10 (52.7) 7 (36.8) 2 (10.5) Table 2. Effect of technique on postoperative visual acuity, number (%). Improvement in Visual Acuity 11 12 13 14 Limbal 1 (9.1) 3 (27.3) 6 (54.5) 1 (9.1) Pars plana 0 6 (54.5) 4 (36.4) 1 (9.1) Technique Table 3. Effect of technique on postoperative red reflex, number (%). Improvement in Red Reflex Technique 11 12 13 14 Limbal 0 4 (21.0) 9 (47.4) 6 (31.6) Pars plana 1 (5.3) 3 (15.8) 10 (52.6) 5 (26.3) lectomy quality, status of retinal periphery, and postoperative refraction. The postoperative increase in visual acuity was significant in both groups. Of the 27 eyes of 19 patients who could cooperate in visual acuity determination with an E-chart before and after surgery (16 and 11 eyes in Techniques A and B, respectively), 24 had a visual acuity worse than 20/200 before surgery, whereas 1 eye had this acuity after surgery. The cause of decreased visual acuity in this case was deep amblyopia unresponsive to proper occlusion therapy. Table 2 shows visual acuity according to the 2 techniques used. There were no statistically significant differences between the 2 techniques in visual acuity improvement. The improvement in estimated red reflex was also significant. Red reflex was evaluated in 45 eyes. Red reflex worse than 20/200 was present in 41 eyes before surgery. After surgery, red reflex was better than 20/40 in all eyes. Table 3 shows the effect on red reflex based on technique. There was no statistically significant difference between the techniques in improvement. In no case did complications such as CME, glaucoma, retinal tear, IOL dislocation, corneal edema, or an increased cup-to-disc ratio occur. Iris capture occurred in 1 case (zonular cataract, Technique B). One eye in each group developed posterior synechias of less than 2 clock hours. Although fibrin formation was more common with Technique B than A, chi-square analysis showed that the difference was not statistically significant (Table 4). Posterior capsulectomy smaller than 3.0 mm was considered inadequate. In the Technique A group, the visual axis was occluded in 1 eye. In other cases with small capsulectomy size, refraction was difficult but did not interfere with vision. The case with the occluded visual axis had an Nd:YAG capsulotomy 3 months after surgery. Inadequate capsulectomy was 3 times more common with Technique A than Technique B; however, the Fisher exact test showed the difference was not statistically significant (Table 5). Refraction was performed at the last examination. In all cases, mean astigmatism after surgery was 1.75 D, with the type being with the rule. Postoperative mean spherical equivalent with Technique A was – 0.64 6 1.02 D and Technique B, – 0.76 6 1.59 D. J CATARACT REFRACT SURG—VOL 25, JUNE 1999 771 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT Table 4. Effect of technique on fibrin formation in the anterior chamber, number (%). Fibrin Formation in Anterior Chamber Technique Yes No Limbal 4 (21.0) 15 (79.0) Pars plana 5 (26.3) 14 (73.7) Table 5. Effect of technique on posterior capsulotomy size, number (%). Capsulectomy Size Technique Inadequate Adequate Limbal 3 (15.8) 16 (84.2) Pars plana 1 (5.3) 18 (94.7) A t test analysis showed the difference was not statistically significant. Discussion The most important goal in pediatric cataract surgery is to provide ideal visual rehabilitation. There is an increasing tendency toward IOL implantation in children to correct aphakia. The success rate of such implantation is improving and the complication rate decreasing because of new surgical techniques and improved IOL quality. Even though more recent studies have shown encouraging results of pediatric IOL implantation, caution in selecting patients for this procedure is crucial, especially in very young children. Visual rehabilitation of unilateral aphakic children is more challenging than bilateral cases. Thus, the minimum age for which IOL implantation should be considered in unilateral cases of pediatric cataract is lower than that for bilateral cases.2,9,12,17 In a survey, the mean age for IOL implantation in children was 3 years in unilateral cases and 5 years in bilateral cases.17 The minimum ages in our series were the same. The maximum age was 10 years in both unilateral and bilateral cases. In calculating IOL power, we aimed for emmetropia and minimizing anisometropia. This is an important factor in visual rehabilitation in children. The correct IOL power leads to more successful amblyopia treatment and increases the chance of binocularity in 772 this critical age period. In other series, however, different approaches have been considered in IOL power calculation. In 1 study, 5 undercorrection was the goal in patients younger than 9 years. In another,7 undercorrection was considered only in children 4 years or younger. The undercorrection was an attempt to neutralize the myopic shift that can occur in growing children. Other authors believe that achievement of emmetropia is vital in patients with a pliable visual system and that its benefits outweigh the consequence of subsequent myopia.3,4 The growth of the globe is almost complete at 2 years of age.18 Thus, the myopic shift in children 3 years and older would be expected to be less. In our series, postoperative refraction was within the range of emmetropia, as planned, and there was no statistically significant difference between the 2 techniques in postoperative refraction. To provide a clear media for visual rehabilitation, primary posterior capsulectomy has been recently recommended. Several approaches to prevent or delay PCO have been studied. Primary posterior capsulotomy with a needle or a vitrectomy cutting device, a limbal or pars plana approach anterior vitrectomy, and primary posterior continuous curvilinear capsulorhexis (PCCC) are some techniques that have been evaluated.5,7,15,16,19,20 The capsulotomy edge produced by continuous curvilinear capsulorhexis is smooth.21 Nevertheless, performing PCCC is technically difficult.16 Capsulorhexis of the anterior capsule in young patients is even more difficult than PCCC.16 We used a vitrector to perform capsulectomies in both capsules, followed by anterior vitrectomy. We found this technique easy and reproducible. There is no agreement whether the IOL should be implanted before or after the primary posterior capsulectomy and anterior vitrectomy. Some advocate removing the posterior capsule and anterior vitreous before IOL implantation.3,7 This can be performed by an anterior segment surgeon or a pediatric ophthalmologist. The anterior vitrectomy can be done in a well-controlled manner under good visibility.15 When the anterior vitrectomy is done, in-the-bag IOL implantation is easily achieved. Dahan and Salmenson3 found no serious complications using this technique in 80 children. Other surgeons prefer to have the IOL in place before removing the posterior capsule5 to allow for an ad- J CATARACT REFRACT SURG—VOL 25, JUNE 1999 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT equate posterior capsulectomy and a better anterior vitrectomy. The advantage of implanting the IOL before the posterior capsulectomy is that the IOL can be safely fixated in the desired plane. The risk of the IOL being pushed out of the capsular bag may be minimized by keeping the infusion in the anterior chamber. Buckley et al.,5 in a prospective study, used a technique that involved endocapsular cataract extraction and PC IOL implantation. However, the posterior capsulotomy and anterior vitrectomy were performed through the pars plana in the 20 patients, all with unilateral cataract. Visual axis clarity was rapidly restored in all patients without further intervention. The authors concluded that there was a considerable advantage to having the lens in place before removing the posterior capsule. In an attempt to determine whether the IOL should be implanted before or after posterior capsulectomy and anterior vitrectomy, an experimental study was done using pediatric autopsy eyes.22 This study found that both techniques were feasible in a clinical setting. We compared the limbal and pars plana approaches in a clinical trial. In our study, the visual results were encouraging, and there was no significant difference between the 2 techniques in postoperative improvement in visual acuity. As well as providing a clear media and optical correction, the aggressive amblyopia therapy was an important factor in achieving such results in our patients. Estimation of the red reflex is a valuable method of evaluating media clarity. There was considerable improvement in red reflex after the surgery and no difference between the 2 techniques in improvement in postoperative estimated red reflex. There is usually a considerable amount of inflammatory reaction after cataract surgery and IOL implantation in children.2,7,15 To reduce postoperative inflammation, we gave a sub-Tenon’s injection of methylprednisolone acetate at the end of surgery in all cases. Nevertheless, fibrin formed in 9 eyes in the early postoperative days. The inflammatory reaction was controlled with frequent instillation of topical steroids and oral prednisolone. The technique used had no significant influence on the amount of postoperative inflammation. Iris capture, adhesion of the iris to the IOL, and posterior synechias have been reported frequently after pediatric cataract surgery and PC IOL implantation when the procedure is not associated with primary pos- terior capsulectomy and anterior vitrectomy.2,8,23 Anterior vitrectomy reduces the rate of such complications,5,7 which were uncommon in our series. There was no significant difference between the 2 techniques in the occurrence of such complications. One objective of primary posterior capsulectomy and anterior vitrectomy is providing long-term clarity of the visual axis. We considered the primary posterior capsulectomy inadequate if it was smaller than 3.0 mm in diameter. This was observed in 4 cases, but only 1 eye required an Nd:YAG capsulotomy. This complication was more common in the limbal approach group, but the difference between techniques was not statistically significant. The advent of the vitrectomy machine reduced the rate of retinal detachment as a late complication of pediatric cataract surgery. Keech and coauthors24 reported 1 case of retinal detachment 6 years after translimbal lensectomy and anterior vitrectomy. No retinal detachment was observed in our series. To properly evaluate the effect of technique on the occurrence of retinal detachment, long-term follow-up is needed. Cystoid macular edema has an effect on visual rehabilitation of children who have lensectomy and IOL implantation. Hoyt and Nickel25 observed CME in 10 of 27 cases of developmental cataract after lensectomy and vitrectomy. Poer and coauthors26 observed no CME in a study of 25 eyes of 18 patients after surgery for management of infantile cataract. Gilbard and coauthors27 reported no CME in 25 eyes of 17 children who had pars plicata lensectomy and vitrectomy. In a study by Pinchoff and coauthors,28 fluorescein angiography performed 4 to 16 weeks after translimbal lensectomy and vitrectomy revealed no CME. Morgan and Franklin29 performed oral fluorescein angiography 3, 6, and 24 weeks after the surgery in patients from 2 months to 7 years and observed no macular leakage. In our series, fluorescein angioscopy was performed 4 to 6 weeks after the surgery, with no CME observed. Different mechanisms for glaucoma in children after cataract surgery have been proposed. Performing lensectomy and vitrectomy permits complete removal of lens material and minimizes postoperative inflammation and consequent pupillary block. In a study with shortterm follow-up, no case of glaucoma was observed in children having lensectomy with a vitrectomy machine. When the follow-up was continued, it became obvious J CATARACT REFRACT SURG—VOL 25, JUNE 1999 773 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT that glaucoma may threaten the vision of children who have lensectomy and vitrectomy years after the surgery.30,31 Recent studies show that the incidence of glaucoma after surgical management of infantile and developmental cataract depends on the duration of follow-up.30,32 In our study, there was no difference between the 2 techniques in the occurrence of glaucoma. Nevertheless, long-term follow-up is needed to make a judgment about the possible effect of technique on the occurrence of glaucoma. In conclusion, when the intervening and background variables were matched there were no statistically significant differences between the limbal and pars plana approaches and the visual and anatomic results were encouraging in both groups. In addition, the rate of complications was minimal and did not differ significantly between techniques. References 1. Hiles DA. Intraocular lens implantation in children with monocular cataracts; 1974 –1983. Ophthalmology 1984; 91:1231–1237 2. Burke JP, Willshaw HE, Young JDH. Intraocular lens implants for uniocular cataracts in childhood. Br J Ophthalmol 1989; 73:860 – 864 3. Dahan E, Salmenson BD. Pseudophakia in children: precautions, technique, and feasibility. J Cataract Refract Surg 1990; 16:75– 82 4. Gimbel HV, Ferensowicz M, Raanan M, DeLuca M. Implantation in children. J Pediatr Ophthalmol Strabismus 1993; 30:69 –79 5. Buckley EG, Klombers LA, Seaber JH, et al. Management of the posterior capsule during pediatric intraocular lens implantation. Am J Ophthalmol 1993; 115: 722–728 6. Vasavada A, Chauhan H. Intraocular lens implantation in infants with congenital cataracts. J Cataract Refract Surg 1994; 20:592–598 7. Basti S, Ravishankar U, Gupta S. Results of a prospective evaluation of three methods of management of pediatric cataracts. Ophthalmology 1996; 103:713–720 8. Brady KM, Atkinson CS, Kilty LA, Hiles DA. Cataract surgery and intraocular lens implantation in children. Am J Ophthalmol 1995; 120:1–9 9. Apple DJ, Solomon KD, Tetz MR, et al. Posterior capsule opacification. Surv Ophthalmol 1992; 37:73–116 10. Sinskey RM, Stoppel JO, Amin P. Long-term results of intraocular lens implantation in pediatric patients. J Cataract Refract Surg 1993; 19:405– 408 774 11. Knight-Nanan D, O’Keefe M, Bowell R. Outcome and complications of intraocular lenses in children with cataract. J Cataract Refract Surg 1996; 22:730 –736 12. Morgan KS, Karcioglu ZA. Secondary cataracts in infants after lensectomies. J Pediatr Ophthalmol Strabismus 1987; 24:45– 48 13. Nishi O. Fibrinous membrane formation on the posterior chamber lens during the early postoperative period. J Cataract Refract Surg 1988; 14:73–77 14. Hiles DA. Visual rehabilitation of aphakic children. III. Intraocular lenses. Surv Ophthalmol 1990; 34:371–379 15. Vasavada A, Desai J. Primary posterior capsulorhexis with and without anterior vitrectomy in congenital cataracts. J Cataract Refract Surg 1997; 23:645– 651 16. Koch DD, Kohnen T. Retrospective comparison of techniques to prevent secondary cataract formation after posterior chamber intraocular lens implantation in infants and children. J Cataract Refract Surg 1997; 23: 657– 663 17. Wilson ME, Bluestein EC, Wang X-H. Current trends in the use of intraocular lenses in children. J Cataract Refract Surg 1994; 20:579 –583 18. Gordon RA, Donzis PB. Refractive development of the human eye. Arch Ophthalmol 1985; 103:785–789 19. Gimbel HV, Neuhann T. Development, advantages, and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg 1990; 16:31–37 20. Zetterström C, Kugelberg U, Oscarson C. Cataract surgery in children with capsulorhexis of anterior and posterior capsules and heparin-surface-modified intraocular lenses. J Cataract Refract Surg 1994; 20:599 – 601 21. Comer RM, Abdulla N, O’Keefe M. Radiofrequency diathermy capsulorhexis of the anterior and posterior capsules in pediatric cataract surgery: preliminary results. J Cataract Refract Surg 1997; 23:641– 644 22. Wang X-H, Wilson ME, Bluestein EC, et al. Pediatric cataract surgery and intraocular lens implantation techniques: a laboratory study. J Cataract Refract Surg 1994; 20:607– 609 23. Kora Y, Inatomi M, Fukado Y, et al. Long-term study of children with implanted intraocular lenses. J Cataract Refract Surg 1992; 18:485– 488 24. Keech RV, Tongue AC, Scott WE. Complications after surgery for congenital and infantile cataracts. Am J Ophthalmol 1989; 108:136 –141 25. Hoyt CS, Nickel D. Aphakic cystoid macular edema; occurrence in infants and children after transpupillary lensectomy and anterior vitrectomy. Arch Ophthalmol 1982; 100:746 –749 26. Poer DV, Helveston EM, Ellis FD. Aphakic cystoid macular edema in children. Arch Ophthalmol 1981; 99:249 – 252 27. Gilbard SM, Peyman GA, Goldberg M. Evaluation for J CATARACT REFRACT SURG—VOL 25, JUNE 1999 PRIMARY POSTERIOR CAPSULECTOMY IN CHILDHOOD CATARACT cystoid maculopathy after pars plicata lensectomy–vitrectomy for congenital cataracts. Ophthalmology 1983; 90: 1201–1206 28. Pinchoff BS, Ellis FD, Helveston EM, Sato SE. Cystoid macular edema in pediatric aphakia. J Pediatr Ophthalmol Strabismus 1988; 25:240 –243 29. Morgan KS, Franklin RM. Oral fluorescein angioscopy in aphakic children. J Pediatric Ophthalmol Strabismus 1984; 21:33–36 30. Simon JW, Mehta N, Simmons ST, et al. Glaucoma after pediatric lensectomy vitrectomy. Ophthalmology 1991; 98:670 – 674 31. Asrani SG, Wilensky JT. Glaucoma after congenital cataract surgery. Ophthalmology 1995; 102:863– 867 32. Brady KM, Atkinson CS, Kilty LA, Hiles DA. Glaucoma after cataract extraction and posterior chamber lens implantation in children. J Cataract Refract Surg 1997; 23: 669 – 674 J CATARACT REFRACT SURG—VOL 25, JUNE 1999 775