- Email: [email protected]
Posterior Capsulectomy in Pediatric Cataract Surgery
Posterior Capsulectomy in Pediatric Cataract Surgery The Necessity of a Choice David BenEzra, MD, PhD, Evelyne Cohen, COrth Objective: The purpose of the study is to evaluate whether a posterior capsulectomy combined with anterior vitrectomy is a necessity in pediatric cataract. Design: The incidence of posterior capsule opacification, the need for additional surgical interventions, and the influence of a primary posterior capsulectomy after cataract surgery in children were evaluated. The analysis was carried out by studying patients' records retrospectively or after prospective follow-up. Participants: In 94 eyes (69 aphakic and 25 pseudophakic), the medical records were studied retrospectively. Twenty-eight eyes (18 aphakic and 10 pseudophakic) were observed prospectively during 1 year after surgery. In 20 eyes (6 aphakic and 14 pseudophakic) of 10 patients with bilateral cataract, a prospective comparison between the 2 eyes of the same patient also was carried out. Intervention: Cataract surgery through the limbus with or without a primary posterior capsulectomy was performed in 114 eyes (43 of these received a posterior chamber intraocular lens [lOLl and 71 remained aphakic). In 28 eyes, the surgery was carried out by way of the pars plana (6 eyes received an anterior chamber IOL and 22 remained aphakic). Main Outcome Measures: Incidence of posterior capsule opacification, the need for secondary surgical intervention, and visual acuity were measured. Results: Opacification of the posterior capsule is observed in all children's eyes when a primary posterior capsulectomy (combined with an anterior vitrectomy) was not carried out. Earlier secondary cataract formation is associated with a younger age and with implantation of an IOL. Eyes undergoing a primary opening of the posterior capsule during the initial surgery of children with bilateral cataract achieved, in most cases, a better visual acuity than did their fellow eyes. Conclusion: Although possibly a choice in older children, a primary posterior capsulectomy combined with anterior vitrectomy is a must in younger children and particularly when implantation of an IOL is planned. Ophthalmology 1997; 104:2168-2174
Surgery of the lens has evolved markedly after improvements in surgical equipment and techniques. Better designs and more biocompatible materials have enabled the safe implantation of intraocular lenses (IOLs) even in Originally received: December 2, 1996. Revision accepted: May 1, 1997. From the Pediatric Ophthalmology Unit, Department of Ophthalmology, Hadassah University Hospital and Medical School, Jerusalem, Israel. Reprint requests to David BenEzra, MD, PhD, Pediatric Ophthalmology Unit, Department of Ophthalmology, Hadassah University Hospital and Medical School, PO Box 12000, Jerusalem 91120, Israel.
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young children. l - s Despite these advances, the critical question of whether a primary posterior capsulectomy (with or without the combination of anterior vitrectomy) is a choice or a must in pediatric cataract surgery remains an open and debatable issue. 6 - 11 The purpose of this study was to evaluate the incidence of secondary cataracts and the need for additional surgical interventions after cataract surgery in children of various age groups. Initially, a primary opening of the posterior capsule was not planned for surgeries performed by way of the limbus. For surgeries carried out by way of the pars plana, the entire posterior capsule was removed routinely. Later, we performed all
BenEzra and Cohen . Posterior Capsulectomy in Pediatric Cataract Surgery cataract surgeries in children by way of the limbus. During the initial period of development of this technique, we arbitrarily performed a primary posterior capsulectomy (combined with an anterior vitrectomy) or kept the posterior capsule intact. Finally, in a selected group of children with bilateral cataract, a primary posterior capsulectomy was carried out in the first eye operated on, whereas during the operation for the second eye, the posterior capsule was kept intact. A comparison between the eyes undergoing a primary posterior capsulectomy and those in which the posterior capsule was kept intact is the subject of this report.
Materials and Methods Children included in this study suffered from either congenital, developmental (unilateral, bilateral), or traumatic cataract and underwent cataract surgery when up to 14 years old. Analysis of the data was performed for each eye as a single factor independent of the etiology of the cataract. The variables studied included the age of the child during the cataract surgery, the type of surgery, the timing of secondary opacification of the posterior capsule, and the need for additional surgical intervention because of secondary cataract affecting visual functions. A retrospective analysis of these parameters was carried out for eyes operated on without implantation of an IOL and eyes operated on with implantation of an IOL. Prospective analysis of similar parameters also was carried out for ten children suffering from bilateral congenital/developmental cataracts. In each of these children, the first eye operated on had a primary posterior capsulectomy combined with anterior vitrectomy during the initial surgery. For the second eye operated on, the posterior capsule was kept intact. All surgeries were carried out by way of the limbus or the pars plana approach as described previously.I.12 An Ocutome device with cutting and aspiration abilities was used to perform the anterior capsulectomy and aspiration of the lenticular material as well as the posterior capsulectomy and anterior vitrectomy when applicable. Necessary adaptations after developments of more adequate instruments and technologies were introduced gradually. 13 For all eyes included in this study, a minimum followup of 12 months was available. Retrospective Analysis This retrospective analysis was carried out in 94 eyes for which a careful follow-up for a minimum of 2 years postsurgery was available in their records. A total of 69 ofthese 94 eyes were aphakic (47 eyes underwent surgery through the limbus and 22 through the pars plana). A total of 25 eyes were pseudophakic: 19 underwent surgery through the limbus and received a posterior chamber IOL, whereas in 6 eyes, the surgery was carried out through the pars plana and received an anterior chamber IOL (4 eyes angle supported and 2 eyes iris supported). During this earlier period of development of our limbal surgical
approach, the initial plan was to keep the posterior capsule intact. However, the posterior capsule was opened inadvertently in 23 eyes during the surgery. Anterior vitrectomy was performed only in three eyes. Prospective Analysis In 21 children (28 eyes) undergoing operation at various ages, the surgery was carried out through the limbus, and the posterior capsule was kept intact. Ten of these eyes received a posterior chamber IOL and 18 remained aphakic. These eyes that were operated on were observed carefully for a period of 12 months, and the earliest signs of posterior capsule opacification were recorded prospectively. An additional prospective evaluation was carried out in 10 additional children (20 eyes) suffering from bilateral cataract. In all, the surgery was carried out through the limbus. These ten children have been observed for a minimum of 3 years. In 7 of these children (14 eyes), posterior chamber IOLs were implanted in both eyes. In three children (six eyes) who were operated on during the same period, no IOLs were implanted. In nine of the children, the first eye that was operated on (always the most affected eye) underwent an intentiona11arge posterior capsu1ectomy combined with anterior vitrectomy. These were performed with the same vitrectomy probe used for the anterior capsulectomy and aspiration of lenticular cortex and nucleus. An Allergen Medical Optics IOL with a 7.0 mm-optic was implanted in seven of "first" eyes and positioned sulcus to sulcus. During surgery of the "second" eyes, the posterior capsule was kept intact. Seven of these second eyes received an IOL implanted within the bag. In five eyes, an Allergen Medical Optics IOL with a 7.0-mm optic was used, and in two eyes, a "star" silicon lens was implanted. In one child operated on at the age of 14 who was receiving an Allergen Medical Optics IOL in both eyes, only a small posterior capsulectomy (without vitrectomy) was performed in the first eye that was operated on. Before including the children with bilateral cataracts in the study, the parents were given a thorough explanation about the surgical techniques to be used for each eye, their advantages, and potential disadvantages. A brief outlook regarding the need for careful follow-up and the expected benefits to be derived from the study also were provided, and the parents were asked to sign an appropriate informed consent form. Follow,up For the eyes evaluated retrospectively, findings of secondary opacifications of the posterior capsule were recorded when observed initially by the examining ophthalmologist or when the optometrist reported difficulties in obtaining "clear and sharp" skyascopic reflex. For the eyes observed prospectively, only findings of evident opacification observed directly at the slit lamp were recorded. The need for a secondary surgical intervention (neodymium:YAG [Nd:YAG] or surgical capsulectomy com-
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Table 1. Incidence of Posterior Capsule Opacification and Secondary Surgical Intervention after Cataract Surgery without Intraocular Lens
Route
Age Range (yrs)
Posterior Capsulectomy
Anterior Vitrectomy
No. of Eyes
Secondary* Cataract [no. (%)]
Limbal Limbal Pars plana
1-12 0.5-10 0.5-6
No Yest Yes
No No Yes
31 16 22
31 (100) 12 (75) o (0)
* Evident
Additionalt Surgical Intervention [no. (%)]
31 (l00) 8 (50) o (0)
opacification of the posterior capsule under the slit lamp or dull skyascopic reflex preventing accurate refraction.
j' Some of the patients have needed more than one single additional intervention t o achieve a clear visual axis.
*Unintentional and unplanned posterior capsule opening occurred during surgery. No anterior vitrectomy was carried out in these cases. bined with anterior vitrectomy) was recorded if either one or more of the following were observed: 1. A drop of visual acuity not amenable to correction by refraction and which correlated with an evident opacification of the posterior capsule observed at the slit lamp. 2. A change in the fixation pattern of the eye operated on and/or the presence of phoria/tropia not detected previously. These functional impairments were correlated also with secondary posterior capsule opacification detected at the slit lamp. 3. Inability to obtain a clear reflex on skyascopy associated with an evident opacification of the posterior capsule. Criterion 1 was the only criterion for children able to cooperate reliably during visual acuity testing. Criteria 2 and 3 were most useful indicators in uncooperative children and those younger than 3 years of age.
Additional Surgical Interventions For the early cases, in which opacification of the posterior capsule was responsible for functional impairment as described above, a surgical capsulectomy combined with anterior vitrectomy was carried out with the patient under general anesthesia. The surgery was performed by way of the limbus (no IOL) or by way of the pars plana (in the presence of an IOL). Later, Nd: YAG laser posterior capsulectomies were performed as the first attempt without sedation (for older cooperative children) or using intravenous propofol (2.6 diisopropylphenol) as a shortacting general anesthetic without intubation. For cases having reopacifications of the posterior capsule after Nd: Y AG laser or a primary marked opacification deemed as inadequate for laser treatment, a surgical posterior capsulectomy combined with anterior vitrectomy by way of the limbus (eyes without IOL) or by way of the pars plana (eyes with IOL) was performed with the patient under general anesthesia using a laryngeal mask. 2170
Results Table 1 illustrates the findings recorded for 69 eyes of children undergoing cataract surgery without IOL implantation. All 31 eyes in which the posterior capsule was kept intact had secondary opacification of the posterior capsule develop, and all have needed at least 1 additional surgical intervention to keep a clear visual axis. In 16 of the eyes, an inadvertent opening of the posterior capsule occurred during the surgery, but no anterior vitrectomy was performed. Of these 16 eyes, 12 eyes (75%) had secondary cataract formation develop, but only in 8 eyes (50%) was the need for an additional surgical intervention recorded. In 22 eyes, the cataract surgery was carried out by way of the pars plana, and the anterior and posterior capsules of the lens were removed combined with an anterior vitrectomy. As expected, secondary cataract formation obstructing the visual axis was not observed in any of these cases, and no additional surgical interventions associated with obstruction of the visual axis were needed (Table 1). Recorded observations for the 25 pseudophakic eyes operated on during the same period show that of the 19 eyes operated on through the limbus, a secondary cataract and an additional surgical intervention were needed for the 12 eyes in which the posterior capsule was kept intact. In four eyes, an inadvertent opening of the posterior capsule occurred during the surgery, but no anterior vitrectomy was performed. These four eyes had a secondary cataract develop, and they had to undergo at least one additional surgical intervention (Table 2). In three eyes of this group, a limited anterior vitrectomy was carried out when the posterior capsule was opened inadvertently during the surgery. Two of these eyes had secondary cataract develop that obstructed the visual axis, but in only one eye was a surgical intervention deemed necessary. In six eyes, a lensectomy, including a large posterior capsulectomy and an anterior vitrectomy, was performed by way of the pars plana. The anterior chamber IOLs (angleor iris-supported) were introduced through an opening at the limbus in these cases. No renewed obstruction of the visual axis by secondary cataract was observed in any of
BenEzra and Cohen . Posterior Capsulectomy in Pediatric Cataract Surgery Table 2. Incidence of Posterior Capsule Opacification and Secondary Surgical Intervention after Cataract Surgery with Intraocular Lens (lOL) Implantation
Surgical Approach
Posterior Capsulectomy
Anterior Vitrectomy
No. of Eyes
Age Range (yrs)
Secondary* Cataract [no. (%)]
Limbal Limbal Limbal Pars planall
No Yes+ Yes+'§ Yes
No No Yes Yes
12 4 3 6
6-12 3-S 3-S 1-3
12 (100) 4 (100) 2 (66.6) a (0)
Additionalt Surgical Intervention [no. (%)] 12 (100) 4 (100) 1 (33.3) a (0)
*t+ See Table 1. § As the capsulectomy was unplanned, its size was kept as small as possible and the vitrectomy was limited to the posterior capsule edges of the inadvertent opening.
II The
IOl, in these cases, was implanted thtough a limbal opening. Either an anterior chamber or an iris supported IOl was used in these early cases.
these eyes, and there was no need for additional surgical intervention associated with this phenomenon (Table 2). Prospective follow-up during a period of 12 months after 28 eyes undergoing surgery through the limbus showed that a close correlation exists between the speed of posterior capsule opacification and the age of the child during the initial surgery (Table 3). All children 6 years of age or younger show a significant opacification of the posterior capsule within 1 year after surgery. In children up to 3 years old, opacification of the posterior capsule was observed in all cases within 6 months after the surgery. In children older than 6 years during the initial surgery, 8 of 10 (80%) had significant opacification of the posterior capsule develop within the first year after surgery (Table 3). Furthermore, within the same age group, eyes with IOLs tended to have posterior capsule opacification develop earlier than aphakic eyes. The comparison between the two eyes of children suffering from bilateral cataracts observed for 3 to 6 years after
surgery is illustrated in Tables 4 and 5. The eyes of children without IOLs (Table 4) and those with IOLs (Table 5) show similar patterns of behavior. All ten eyes in which the posterior capsule was kept intact and one eye in which only a small posterior capsulectomy was perfonned have needed at least one additional surgical intervention. In 4 (36%) of these 11 eyes, a second intervention was needed and had to be carried out 6 to 18 months after the first intervention. Six to 8 weeks after the initial surgery, the visual acuity achieved by these "second eyes" was similar to that reached by the "first" eyes that were operated on. Opening of the opaque capsule immediately improved the visual acuity in all treated eyes. However, in most cases, the visual acuity recorded for these eyes during the last follow-up visit did not reach the level of acuity shown by their fellow eyes undergoing a primary posterior capsulectomy and anterior vitrectomy (Tables 4 and 5). No major complications were observed in any of these 20 eyes after a maximum followup of 6 years.
Table 3. Timing of Earliest Posterior Capsule Opacification after Cataract Surgery of Children Operated at Various Ages Age at Surgery (yrs)
Time of Opacification after Surgery (mos) No. of Eyes
<3 [no. (%)]
4
4 (100)
<1 >1-3 >3-6 >6
6 S lOt
Total
2S§
* lr, these
eyes, an IOl was implanted.
>3-6 [no. (%)]
>6-12 [no. (%)]
Total (%) 100 100 100 SO
3* (SO) 2* (2S)
3 (SO) S (62.S) 2* (20)
1 (12.S) 6+ (60)
9 (32.1)
10 (3S.7)
7 (2S)
92.S
t Two (aphakic) eyes in this age gtoup did not develop significant opacification of the posterior capsule during this period of follow-up, Both eyes demonstrated marked opacification of the posterior capsule and poor visual acuity when examined 22 and 30 months after the surgery. :j: Three of these six eyes received an IOL.
§ Of the 28 eyes, 10 are pseudophakic and 18 aphakic.
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Table 4. Posterior Capsule Opacification and Secondary Surgical Interventions in Aphakic Eyes of Children with Bilateral Cataracts Age at Surgery (yrs)
Patient No.
3 2
4
3
7
= right eye; OS = left eye. * Best-corrected visual acuity before
Eye
Posterior Capsulectomy Anterior Vitrectomy
Additional Surgeries
00 OS 00 OS 00 OS
Yes No Yes No No Yes
0 2t 0
It it
0
Recorded Visual Acuity
Before *
After
20/30 20/100 20/25 20/200 20/200 20/20
20/30 20/40 20/25 20/50 20/25 20/20
00
performing the "last" additional surgical intervention.
t Nd:YAG capsulectomy.
t S urgical capsulectomy combined with anterior vitrectomy.
Discussion In the past, leaving the posterior capsule intact when performing a cataract extraction in young children was a difficult task. With the development of more refined microsurgical instruments with linear controls, inadvertent opening of the posterior capsule during pediatric cataract surgery became less common. On follow-up, we realized that eyes with unintentional rupture of the posterior capsule had a decreased need for secondary surgical interventions after surgery. When IOL implantations were performed during this period, it quickly became evident that
the final visual outcome in the eyes in which the posterior capsule remained intact was lower than in those in which a rupture had occurred. In addition, eyes in which a combined anterior vitrectomy was performed had a milder postoperative inflammatory course. Therefore, during the early 1980s, we advocated to perform a primary posterior capsulectomy combined with an anterior vitrectomy before implanting an IOL in children' s eyesY This technique provided a constant clear visual axis and prevented the need for additional surgical interventions during a long-term follow-up. However, harshobjections based on two major potential disadvantages were raised by col-
Table 5. Posterior Capsule Opacification and Secondary Surgical Interventions in Pseudophakic Eyes of Children with Bilateral Cataracts Age at Surgery (yrs)
Patient No.
4
6
5
5
6
5
7
6
8
12
9
14
10
12
00
= right eye;
OS
Eye
Posterior Capsulectomy Anterior Vitrectomy
00 OS 00 OS 00 OS 00 OS 00 OS 00 OS 00 OS
Yes No Yes No Yes No No Yes Yes No No§ No Yes No
= left eye.
*H See Table 4. § On ly a small posterior capsulectomy with out anterior vitrectomy was p erformed in this eye.
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Additional Surgeries
0 It 0 2t:J: 0 2t:J:
it
0 0
it it
2t 0
it
Recorded Visual Acuity
Before*
After
20/40 20/200 20/30 20/200 20/40 20/100 20/200 20/20 20/20 20/80 20/200 20/200 20/25 20/200
20/40 20/60 20/30 20/40 20/40 20/80 20/80 20/20 20/20 20/30 20/40 20/80 20/25 20/25
BenEzra and Cohen . Posterior Capsulectomy in Pediatric Cataract Surgery leagues and were of concern to us as well: the theoretical fear for the induction of macular edema after the vitrectomy and the difficulty of inserting the IOL within the bag in the presence of a large posterior capsulectomy. Therefore, only a few surgeons followed the recommendation to perform a primary posterior capsulectomy9 and a combined anterior vitrectomy4,14 before inserting the IOL either in the bag or sulcus to sulcus. Practically, however, based on a long-term follow-up, no macular edema of clinical significance interfering with the development of vision has been observed in the children's eyes undergoing a primary posterior capsulectomy and anterior vitrectomy. In addition, positioning an IOL within the bag in the presence of a round posterior capsulectomy is easily achievable in these children's eyes if the edges of the capsulectomy are freed from formed vitreous. Surgeons reluctant to insert the IOL in the presence of a posterior capsulectomy suggest performing a posterior capsulectomy after placing the IOL within the bag using the vitrectomy probe either by way of the limbus 15 or by way of the pars plana. 16,17 Others advocate the use of Nd:YAG laser aftedmrgery.8,18 From our experience, performing a surgical posterior capsulectomy after inserting the IOL did not yielp satisfactory results. 12 Conversely, it appears to us that postoperative Y AG posterior capsulectomy may be a viable option. However, this technique is not withouFrisks, and in young children, it has to be carried out with the child under general anesthesia. In addition, one laser capsulectomy may not provide for a constant clear visual axis as observed in the current study and also reported by others. 18 Furthermore, despite a first N d: Y AG laser capsulectomy, a secondary surgical intervention cannot be avoided, especially in some children of the younger age groups. An interesting and challenging attitude toward the posterior capsule also has been suggested. 19 In this method, a manual posterior ~apsulorhexis is performed, and the IOL optic is protruded backward to prevent possible migration of the reproliferating lenticular cells. Although interesting, this technique still has to withstand the test of time. Definitive conclusions regarding the best and most appropriate methodology for cataract surgery with IOL implantation in children have been hampered by three major factors: (1) unavailability of thorough information based on large series of eyes that were operated on; (2) the heterogeneity with Illultiple confounding factors observed in individual children; and (3) the lack of long-term follow-up. The ultimate test for any suggested ocular surgical approach is the final visual acuity achieved by the eyes that were operated on and the number of interventions needed to achieve the best outcome. In the current study, all eyes undergoing a primary capsulectomy combined with an anterior vitrectomy (with or without IOL) did not need additional surgeries"whereas all eyes in which the posterior capsule was kept intact had to undergo one or more secondary inter.lle!1tions. Moreover, within the group of bilateral cataracts observed prospectively for a long period, most of the eyes with a primary posterior
capsulectomy and anterior vitrectomy achieved a better final visual acuity than did their fellow eyes. These results most probably were because the eyes with a primary posterior capsulectomy had an undisturbed and continuous clear visual axis. Their fellow eyes, conversely, had secondary opacification of the posterior capsule develop and had a significant drop of vision before the additional surgical intervention was attempted. During this period, amblyogenic processes may have taken place, and therefore the final visual outcome remained lower. Because the eyes with intact posterior capsule showed a good visual acuity shortly after the initial surgery, it is not improbable that the additional surgeries also may have caused direct damage in preventing these eyes from having a visual acuity develop similar to their fellow eyes. The data derived from the current study show unequivocally that opacification of the posterior capsule interfering with vision occurs in 100% of children's eyes undergoing cataract surgery. The younger the patient, the more rapid the opacification and the earlier the interference with the visual functions. In cases without IOL, inadvertent opening of the posterior capsule during the initial surgery interfered, to some extent, with the formation of a secondary cataract and the need for an additional intervention in some of these eyes. In eyes of young children receiving an IOL, opening of the posterior capsule only (without a combined vitrectomy) did not interfere with the secondary cataract formation. Performing a primary opening of the posterior capsule combined with anterior vitrectomy before inserting the IOL prevented the secondary opacification and the obstruction of the visual axis in these eyes. Finally, the unique opportunity to compare between the two eyes of the same patient with bilateral cataract provided, in our opinion, the ultimate answer regarding the necessity of performing a primary posterior capsulectomy combined with anterior vitrectomy in young children. As for the older children and young adults, the "choice" remains until proved otherwise.
References l. BenEzra D, Paez JH, Frucht Y. Monocular and binocular
2. 3. 4. 5. 6. 7.
congenital cataract. Ophthalmic Paediatrics and Genetics 1983;2:123-8. BenEzra D, Paez JH. Congenital cataract and intraocular lenses. Am J Ophthalmol 1983;96:311-4. Hiles DA. Intraocular lens implantation in children with monocular cataracts 1974-1983. Ophthalmology 1984;91: 1231-7. Dahan E, Salmenson BD. Pseudophakia in children: precautions, technique, and feasibility. J Cataract Refract Surg 1990; 16:75-82. de Courten CH, Bucher PJM, BenEzra D. Experience with HEMA lenses in paediatric cataract. European Journal of Implant and Refractive Surgery 1990;2:315-8. Menezo JL, Esteve JT, Perez-Torregrosa VT. IOL implantation in children-17 years experience. European Journal of Implant and Refractive Surgery 1994; 6:251-6. BenEzra D. Cataract aphakia and amblyopia-the dilemmas of paediatric ophthalmology [guest editorial]. Euro-
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8. 9.
10. 11. 12. 13.
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pean Journal of Implant and Refractive Surgery 1990; 2:239-40. Gimbel HV, Ferensowicz M, Raanan M, De Luca M. Implantation in children. J Pediatr Ophthalmol Strabismus 1993;30:69-79. Zetterstrom 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;20:599-60l. Crouch ER Jr, Pressman SH, Crouch ER. Posterior chamber intraocular lenses: long-term results in pediatric cataract patients. J Pediatr Ophthalmol Strabismus 1995;32:210-8. Brady KM, Atkinson CS, Kilty LA, Hiles DA. Author reply [letter]. Am J Ophthalmol 1996; 121:227. BenEzra D. The surgical approaches to paediatric cataract. European Journal of Implant and Refractive Surgery 1990; 2:241-4. BenEzra D. Cataract surgery and intraocular lens implantation in children [letter]. Am J Ophthalmol 1996; 121:224-5.
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14. Cheng KP. Pediatric cataracts. Curr Opin Ophthalmol 1996;7:63-8. 15. Mackool RJ, Chhatiawala H. Pediatric cataract surgery and intraocular lens implantation: a new technique for preventing or excising postoperative secondary membranes. J Cataract Refract Surg 1991; 17:62-6. 16. Buckley EG, Klombers LA, Seaber JH, et al. Management of the posterior capsule during pediatric intraocular lens implantation. Am J Ophthalmol 1993; 115:722-8. 17. Awner S, Buckley EG, De Varo JM, Seaber JH. Unilateral pseudophakia in children under 4 years. J Pediatr Ophthalmol Strabismus 1996;33:230-6. 18. Brady KM, Atkinson CS, Kilty LA, Hiles DA. Cataract surgery and intraocular lens implantation in children. Am J Ophthalmol 1995; 120:1-9. 19. Gimbel HV, DeBroff BM. Posterior capsulorhexis with optic capture: maintaining a clear visual axis after pediatric cataract surgery. J Cataract Refract Surg 1994;20:658-64.
Surgery of the lens has evolved markedly after improvements in surgical equipment and techniques. Better designs and more biocompatible materials have enabled the safe implantation of intraocular lenses (IOLs) even in Originally received: December 2, 1996. Revision accepted: May 1, 1997. From the Pediatric Ophthalmology Unit, Department of Ophthalmology, Hadassah University Hospital and Medical School, Jerusalem, Israel. Reprint requests to David BenEzra, MD, PhD, Pediatric Ophthalmology Unit, Department of Ophthalmology, Hadassah University Hospital and Medical School, PO Box 12000, Jerusalem 91120, Israel.
2168
young children. l - s Despite these advances, the critical question of whether a primary posterior capsulectomy (with or without the combination of anterior vitrectomy) is a choice or a must in pediatric cataract surgery remains an open and debatable issue. 6 - 11 The purpose of this study was to evaluate the incidence of secondary cataracts and the need for additional surgical interventions after cataract surgery in children of various age groups. Initially, a primary opening of the posterior capsule was not planned for surgeries performed by way of the limbus. For surgeries carried out by way of the pars plana, the entire posterior capsule was removed routinely. Later, we performed all
BenEzra and Cohen . Posterior Capsulectomy in Pediatric Cataract Surgery cataract surgeries in children by way of the limbus. During the initial period of development of this technique, we arbitrarily performed a primary posterior capsulectomy (combined with an anterior vitrectomy) or kept the posterior capsule intact. Finally, in a selected group of children with bilateral cataract, a primary posterior capsulectomy was carried out in the first eye operated on, whereas during the operation for the second eye, the posterior capsule was kept intact. A comparison between the eyes undergoing a primary posterior capsulectomy and those in which the posterior capsule was kept intact is the subject of this report.
Materials and Methods Children included in this study suffered from either congenital, developmental (unilateral, bilateral), or traumatic cataract and underwent cataract surgery when up to 14 years old. Analysis of the data was performed for each eye as a single factor independent of the etiology of the cataract. The variables studied included the age of the child during the cataract surgery, the type of surgery, the timing of secondary opacification of the posterior capsule, and the need for additional surgical intervention because of secondary cataract affecting visual functions. A retrospective analysis of these parameters was carried out for eyes operated on without implantation of an IOL and eyes operated on with implantation of an IOL. Prospective analysis of similar parameters also was carried out for ten children suffering from bilateral congenital/developmental cataracts. In each of these children, the first eye operated on had a primary posterior capsulectomy combined with anterior vitrectomy during the initial surgery. For the second eye operated on, the posterior capsule was kept intact. All surgeries were carried out by way of the limbus or the pars plana approach as described previously.I.12 An Ocutome device with cutting and aspiration abilities was used to perform the anterior capsulectomy and aspiration of the lenticular material as well as the posterior capsulectomy and anterior vitrectomy when applicable. Necessary adaptations after developments of more adequate instruments and technologies were introduced gradually. 13 For all eyes included in this study, a minimum followup of 12 months was available. Retrospective Analysis This retrospective analysis was carried out in 94 eyes for which a careful follow-up for a minimum of 2 years postsurgery was available in their records. A total of 69 ofthese 94 eyes were aphakic (47 eyes underwent surgery through the limbus and 22 through the pars plana). A total of 25 eyes were pseudophakic: 19 underwent surgery through the limbus and received a posterior chamber IOL, whereas in 6 eyes, the surgery was carried out through the pars plana and received an anterior chamber IOL (4 eyes angle supported and 2 eyes iris supported). During this earlier period of development of our limbal surgical
approach, the initial plan was to keep the posterior capsule intact. However, the posterior capsule was opened inadvertently in 23 eyes during the surgery. Anterior vitrectomy was performed only in three eyes. Prospective Analysis In 21 children (28 eyes) undergoing operation at various ages, the surgery was carried out through the limbus, and the posterior capsule was kept intact. Ten of these eyes received a posterior chamber IOL and 18 remained aphakic. These eyes that were operated on were observed carefully for a period of 12 months, and the earliest signs of posterior capsule opacification were recorded prospectively. An additional prospective evaluation was carried out in 10 additional children (20 eyes) suffering from bilateral cataract. In all, the surgery was carried out through the limbus. These ten children have been observed for a minimum of 3 years. In 7 of these children (14 eyes), posterior chamber IOLs were implanted in both eyes. In three children (six eyes) who were operated on during the same period, no IOLs were implanted. In nine of the children, the first eye that was operated on (always the most affected eye) underwent an intentiona11arge posterior capsu1ectomy combined with anterior vitrectomy. These were performed with the same vitrectomy probe used for the anterior capsulectomy and aspiration of lenticular cortex and nucleus. An Allergen Medical Optics IOL with a 7.0 mm-optic was implanted in seven of "first" eyes and positioned sulcus to sulcus. During surgery of the "second" eyes, the posterior capsule was kept intact. Seven of these second eyes received an IOL implanted within the bag. In five eyes, an Allergen Medical Optics IOL with a 7.0-mm optic was used, and in two eyes, a "star" silicon lens was implanted. In one child operated on at the age of 14 who was receiving an Allergen Medical Optics IOL in both eyes, only a small posterior capsulectomy (without vitrectomy) was performed in the first eye that was operated on. Before including the children with bilateral cataracts in the study, the parents were given a thorough explanation about the surgical techniques to be used for each eye, their advantages, and potential disadvantages. A brief outlook regarding the need for careful follow-up and the expected benefits to be derived from the study also were provided, and the parents were asked to sign an appropriate informed consent form. Follow,up For the eyes evaluated retrospectively, findings of secondary opacifications of the posterior capsule were recorded when observed initially by the examining ophthalmologist or when the optometrist reported difficulties in obtaining "clear and sharp" skyascopic reflex. For the eyes observed prospectively, only findings of evident opacification observed directly at the slit lamp were recorded. The need for a secondary surgical intervention (neodymium:YAG [Nd:YAG] or surgical capsulectomy com-
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Table 1. Incidence of Posterior Capsule Opacification and Secondary Surgical Intervention after Cataract Surgery without Intraocular Lens
Route
Age Range (yrs)
Posterior Capsulectomy
Anterior Vitrectomy
No. of Eyes
Secondary* Cataract [no. (%)]
Limbal Limbal Pars plana
1-12 0.5-10 0.5-6
No Yest Yes
No No Yes
31 16 22
31 (100) 12 (75) o (0)
* Evident
Additionalt Surgical Intervention [no. (%)]
31 (l00) 8 (50) o (0)
opacification of the posterior capsule under the slit lamp or dull skyascopic reflex preventing accurate refraction.
j' Some of the patients have needed more than one single additional intervention t o achieve a clear visual axis.
*Unintentional and unplanned posterior capsule opening occurred during surgery. No anterior vitrectomy was carried out in these cases. bined with anterior vitrectomy) was recorded if either one or more of the following were observed: 1. A drop of visual acuity not amenable to correction by refraction and which correlated with an evident opacification of the posterior capsule observed at the slit lamp. 2. A change in the fixation pattern of the eye operated on and/or the presence of phoria/tropia not detected previously. These functional impairments were correlated also with secondary posterior capsule opacification detected at the slit lamp. 3. Inability to obtain a clear reflex on skyascopy associated with an evident opacification of the posterior capsule. Criterion 1 was the only criterion for children able to cooperate reliably during visual acuity testing. Criteria 2 and 3 were most useful indicators in uncooperative children and those younger than 3 years of age.
Additional Surgical Interventions For the early cases, in which opacification of the posterior capsule was responsible for functional impairment as described above, a surgical capsulectomy combined with anterior vitrectomy was carried out with the patient under general anesthesia. The surgery was performed by way of the limbus (no IOL) or by way of the pars plana (in the presence of an IOL). Later, Nd: YAG laser posterior capsulectomies were performed as the first attempt without sedation (for older cooperative children) or using intravenous propofol (2.6 diisopropylphenol) as a shortacting general anesthetic without intubation. For cases having reopacifications of the posterior capsule after Nd: Y AG laser or a primary marked opacification deemed as inadequate for laser treatment, a surgical posterior capsulectomy combined with anterior vitrectomy by way of the limbus (eyes without IOL) or by way of the pars plana (eyes with IOL) was performed with the patient under general anesthesia using a laryngeal mask. 2170
Results Table 1 illustrates the findings recorded for 69 eyes of children undergoing cataract surgery without IOL implantation. All 31 eyes in which the posterior capsule was kept intact had secondary opacification of the posterior capsule develop, and all have needed at least 1 additional surgical intervention to keep a clear visual axis. In 16 of the eyes, an inadvertent opening of the posterior capsule occurred during the surgery, but no anterior vitrectomy was performed. Of these 16 eyes, 12 eyes (75%) had secondary cataract formation develop, but only in 8 eyes (50%) was the need for an additional surgical intervention recorded. In 22 eyes, the cataract surgery was carried out by way of the pars plana, and the anterior and posterior capsules of the lens were removed combined with an anterior vitrectomy. As expected, secondary cataract formation obstructing the visual axis was not observed in any of these cases, and no additional surgical interventions associated with obstruction of the visual axis were needed (Table 1). Recorded observations for the 25 pseudophakic eyes operated on during the same period show that of the 19 eyes operated on through the limbus, a secondary cataract and an additional surgical intervention were needed for the 12 eyes in which the posterior capsule was kept intact. In four eyes, an inadvertent opening of the posterior capsule occurred during the surgery, but no anterior vitrectomy was performed. These four eyes had a secondary cataract develop, and they had to undergo at least one additional surgical intervention (Table 2). In three eyes of this group, a limited anterior vitrectomy was carried out when the posterior capsule was opened inadvertently during the surgery. Two of these eyes had secondary cataract develop that obstructed the visual axis, but in only one eye was a surgical intervention deemed necessary. In six eyes, a lensectomy, including a large posterior capsulectomy and an anterior vitrectomy, was performed by way of the pars plana. The anterior chamber IOLs (angleor iris-supported) were introduced through an opening at the limbus in these cases. No renewed obstruction of the visual axis by secondary cataract was observed in any of
BenEzra and Cohen . Posterior Capsulectomy in Pediatric Cataract Surgery Table 2. Incidence of Posterior Capsule Opacification and Secondary Surgical Intervention after Cataract Surgery with Intraocular Lens (lOL) Implantation
Surgical Approach
Posterior Capsulectomy
Anterior Vitrectomy
No. of Eyes
Age Range (yrs)
Secondary* Cataract [no. (%)]
Limbal Limbal Limbal Pars planall
No Yes+ Yes+'§ Yes
No No Yes Yes
12 4 3 6
6-12 3-S 3-S 1-3
12 (100) 4 (100) 2 (66.6) a (0)
Additionalt Surgical Intervention [no. (%)] 12 (100) 4 (100) 1 (33.3) a (0)
*t+ See Table 1. § As the capsulectomy was unplanned, its size was kept as small as possible and the vitrectomy was limited to the posterior capsule edges of the inadvertent opening.
II The
IOl, in these cases, was implanted thtough a limbal opening. Either an anterior chamber or an iris supported IOl was used in these early cases.
these eyes, and there was no need for additional surgical intervention associated with this phenomenon (Table 2). Prospective follow-up during a period of 12 months after 28 eyes undergoing surgery through the limbus showed that a close correlation exists between the speed of posterior capsule opacification and the age of the child during the initial surgery (Table 3). All children 6 years of age or younger show a significant opacification of the posterior capsule within 1 year after surgery. In children up to 3 years old, opacification of the posterior capsule was observed in all cases within 6 months after the surgery. In children older than 6 years during the initial surgery, 8 of 10 (80%) had significant opacification of the posterior capsule develop within the first year after surgery (Table 3). Furthermore, within the same age group, eyes with IOLs tended to have posterior capsule opacification develop earlier than aphakic eyes. The comparison between the two eyes of children suffering from bilateral cataracts observed for 3 to 6 years after
surgery is illustrated in Tables 4 and 5. The eyes of children without IOLs (Table 4) and those with IOLs (Table 5) show similar patterns of behavior. All ten eyes in which the posterior capsule was kept intact and one eye in which only a small posterior capsulectomy was perfonned have needed at least one additional surgical intervention. In 4 (36%) of these 11 eyes, a second intervention was needed and had to be carried out 6 to 18 months after the first intervention. Six to 8 weeks after the initial surgery, the visual acuity achieved by these "second eyes" was similar to that reached by the "first" eyes that were operated on. Opening of the opaque capsule immediately improved the visual acuity in all treated eyes. However, in most cases, the visual acuity recorded for these eyes during the last follow-up visit did not reach the level of acuity shown by their fellow eyes undergoing a primary posterior capsulectomy and anterior vitrectomy (Tables 4 and 5). No major complications were observed in any of these 20 eyes after a maximum followup of 6 years.
Table 3. Timing of Earliest Posterior Capsule Opacification after Cataract Surgery of Children Operated at Various Ages Age at Surgery (yrs)
Time of Opacification after Surgery (mos) No. of Eyes
<3 [no. (%)]
4
4 (100)
<1 >1-3 >3-6 >6
6 S lOt
Total
2S§
* lr, these
eyes, an IOl was implanted.
>3-6 [no. (%)]
>6-12 [no. (%)]
Total (%) 100 100 100 SO
3* (SO) 2* (2S)
3 (SO) S (62.S) 2* (20)
1 (12.S) 6+ (60)
9 (32.1)
10 (3S.7)
7 (2S)
92.S
t Two (aphakic) eyes in this age gtoup did not develop significant opacification of the posterior capsule during this period of follow-up, Both eyes demonstrated marked opacification of the posterior capsule and poor visual acuity when examined 22 and 30 months after the surgery. :j: Three of these six eyes received an IOL.
§ Of the 28 eyes, 10 are pseudophakic and 18 aphakic.
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Table 4. Posterior Capsule Opacification and Secondary Surgical Interventions in Aphakic Eyes of Children with Bilateral Cataracts Age at Surgery (yrs)
Patient No.
3 2
4
3
7
= right eye; OS = left eye. * Best-corrected visual acuity before
Eye
Posterior Capsulectomy Anterior Vitrectomy
Additional Surgeries
00 OS 00 OS 00 OS
Yes No Yes No No Yes
0 2t 0
It it
0
Recorded Visual Acuity
Before *
After
20/30 20/100 20/25 20/200 20/200 20/20
20/30 20/40 20/25 20/50 20/25 20/20
00
performing the "last" additional surgical intervention.
t Nd:YAG capsulectomy.
t S urgical capsulectomy combined with anterior vitrectomy.
Discussion In the past, leaving the posterior capsule intact when performing a cataract extraction in young children was a difficult task. With the development of more refined microsurgical instruments with linear controls, inadvertent opening of the posterior capsule during pediatric cataract surgery became less common. On follow-up, we realized that eyes with unintentional rupture of the posterior capsule had a decreased need for secondary surgical interventions after surgery. When IOL implantations were performed during this period, it quickly became evident that
the final visual outcome in the eyes in which the posterior capsule remained intact was lower than in those in which a rupture had occurred. In addition, eyes in which a combined anterior vitrectomy was performed had a milder postoperative inflammatory course. Therefore, during the early 1980s, we advocated to perform a primary posterior capsulectomy combined with an anterior vitrectomy before implanting an IOL in children' s eyesY This technique provided a constant clear visual axis and prevented the need for additional surgical interventions during a long-term follow-up. However, harshobjections based on two major potential disadvantages were raised by col-
Table 5. Posterior Capsule Opacification and Secondary Surgical Interventions in Pseudophakic Eyes of Children with Bilateral Cataracts Age at Surgery (yrs)
Patient No.
4
6
5
5
6
5
7
6
8
12
9
14
10
12
00
= right eye;
OS
Eye
Posterior Capsulectomy Anterior Vitrectomy
00 OS 00 OS 00 OS 00 OS 00 OS 00 OS 00 OS
Yes No Yes No Yes No No Yes Yes No No§ No Yes No
= left eye.
*H See Table 4. § On ly a small posterior capsulectomy with out anterior vitrectomy was p erformed in this eye.
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Additional Surgeries
0 It 0 2t:J: 0 2t:J:
it
0 0
it it
2t 0
it
Recorded Visual Acuity
Before*
After
20/40 20/200 20/30 20/200 20/40 20/100 20/200 20/20 20/20 20/80 20/200 20/200 20/25 20/200
20/40 20/60 20/30 20/40 20/40 20/80 20/80 20/20 20/20 20/30 20/40 20/80 20/25 20/25
BenEzra and Cohen . Posterior Capsulectomy in Pediatric Cataract Surgery leagues and were of concern to us as well: the theoretical fear for the induction of macular edema after the vitrectomy and the difficulty of inserting the IOL within the bag in the presence of a large posterior capsulectomy. Therefore, only a few surgeons followed the recommendation to perform a primary posterior capsulectomy9 and a combined anterior vitrectomy4,14 before inserting the IOL either in the bag or sulcus to sulcus. Practically, however, based on a long-term follow-up, no macular edema of clinical significance interfering with the development of vision has been observed in the children's eyes undergoing a primary posterior capsulectomy and anterior vitrectomy. In addition, positioning an IOL within the bag in the presence of a round posterior capsulectomy is easily achievable in these children's eyes if the edges of the capsulectomy are freed from formed vitreous. Surgeons reluctant to insert the IOL in the presence of a posterior capsulectomy suggest performing a posterior capsulectomy after placing the IOL within the bag using the vitrectomy probe either by way of the limbus 15 or by way of the pars plana. 16,17 Others advocate the use of Nd:YAG laser aftedmrgery.8,18 From our experience, performing a surgical posterior capsulectomy after inserting the IOL did not yielp satisfactory results. 12 Conversely, it appears to us that postoperative Y AG posterior capsulectomy may be a viable option. However, this technique is not withouFrisks, and in young children, it has to be carried out with the child under general anesthesia. In addition, one laser capsulectomy may not provide for a constant clear visual axis as observed in the current study and also reported by others. 18 Furthermore, despite a first N d: Y AG laser capsulectomy, a secondary surgical intervention cannot be avoided, especially in some children of the younger age groups. An interesting and challenging attitude toward the posterior capsule also has been suggested. 19 In this method, a manual posterior ~apsulorhexis is performed, and the IOL optic is protruded backward to prevent possible migration of the reproliferating lenticular cells. Although interesting, this technique still has to withstand the test of time. Definitive conclusions regarding the best and most appropriate methodology for cataract surgery with IOL implantation in children have been hampered by three major factors: (1) unavailability of thorough information based on large series of eyes that were operated on; (2) the heterogeneity with Illultiple confounding factors observed in individual children; and (3) the lack of long-term follow-up. The ultimate test for any suggested ocular surgical approach is the final visual acuity achieved by the eyes that were operated on and the number of interventions needed to achieve the best outcome. In the current study, all eyes undergoing a primary capsulectomy combined with an anterior vitrectomy (with or without IOL) did not need additional surgeries"whereas all eyes in which the posterior capsule was kept intact had to undergo one or more secondary inter.lle!1tions. Moreover, within the group of bilateral cataracts observed prospectively for a long period, most of the eyes with a primary posterior
capsulectomy and anterior vitrectomy achieved a better final visual acuity than did their fellow eyes. These results most probably were because the eyes with a primary posterior capsulectomy had an undisturbed and continuous clear visual axis. Their fellow eyes, conversely, had secondary opacification of the posterior capsule develop and had a significant drop of vision before the additional surgical intervention was attempted. During this period, amblyogenic processes may have taken place, and therefore the final visual outcome remained lower. Because the eyes with intact posterior capsule showed a good visual acuity shortly after the initial surgery, it is not improbable that the additional surgeries also may have caused direct damage in preventing these eyes from having a visual acuity develop similar to their fellow eyes. The data derived from the current study show unequivocally that opacification of the posterior capsule interfering with vision occurs in 100% of children's eyes undergoing cataract surgery. The younger the patient, the more rapid the opacification and the earlier the interference with the visual functions. In cases without IOL, inadvertent opening of the posterior capsule during the initial surgery interfered, to some extent, with the formation of a secondary cataract and the need for an additional intervention in some of these eyes. In eyes of young children receiving an IOL, opening of the posterior capsule only (without a combined vitrectomy) did not interfere with the secondary cataract formation. Performing a primary opening of the posterior capsule combined with anterior vitrectomy before inserting the IOL prevented the secondary opacification and the obstruction of the visual axis in these eyes. Finally, the unique opportunity to compare between the two eyes of the same patient with bilateral cataract provided, in our opinion, the ultimate answer regarding the necessity of performing a primary posterior capsulectomy combined with anterior vitrectomy in young children. As for the older children and young adults, the "choice" remains until proved otherwise.
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congenital cataract. Ophthalmic Paediatrics and Genetics 1983;2:123-8. BenEzra D, Paez JH. Congenital cataract and intraocular lenses. Am J Ophthalmol 1983;96:311-4. Hiles DA. Intraocular lens implantation in children with monocular cataracts 1974-1983. Ophthalmology 1984;91: 1231-7. Dahan E, Salmenson BD. Pseudophakia in children: precautions, technique, and feasibility. J Cataract Refract Surg 1990; 16:75-82. de Courten CH, Bucher PJM, BenEzra D. Experience with HEMA lenses in paediatric cataract. European Journal of Implant and Refractive Surgery 1990;2:315-8. Menezo JL, Esteve JT, Perez-Torregrosa VT. IOL implantation in children-17 years experience. European Journal of Implant and Refractive Surgery 1994; 6:251-6. BenEzra D. Cataract aphakia and amblyopia-the dilemmas of paediatric ophthalmology [guest editorial]. Euro-
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pean Journal of Implant and Refractive Surgery 1990; 2:239-40. Gimbel HV, Ferensowicz M, Raanan M, De Luca M. Implantation in children. J Pediatr Ophthalmol Strabismus 1993;30:69-79. Zetterstrom 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;20:599-60l. Crouch ER Jr, Pressman SH, Crouch ER. Posterior chamber intraocular lenses: long-term results in pediatric cataract patients. J Pediatr Ophthalmol Strabismus 1995;32:210-8. Brady KM, Atkinson CS, Kilty LA, Hiles DA. Author reply [letter]. Am J Ophthalmol 1996; 121:227. BenEzra D. The surgical approaches to paediatric cataract. European Journal of Implant and Refractive Surgery 1990; 2:241-4. BenEzra D. Cataract surgery and intraocular lens implantation in children [letter]. Am J Ophthalmol 1996; 121:224-5.
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14. Cheng KP. Pediatric cataracts. Curr Opin Ophthalmol 1996;7:63-8. 15. Mackool RJ, Chhatiawala H. Pediatric cataract surgery and intraocular lens implantation: a new technique for preventing or excising postoperative secondary membranes. J Cataract Refract Surg 1991; 17:62-6. 16. Buckley EG, Klombers LA, Seaber JH, et al. Management of the posterior capsule during pediatric intraocular lens implantation. Am J Ophthalmol 1993; 115:722-8. 17. Awner S, Buckley EG, De Varo JM, Seaber JH. Unilateral pseudophakia in children under 4 years. J Pediatr Ophthalmol Strabismus 1996;33:230-6. 18. Brady KM, Atkinson CS, Kilty LA, Hiles DA. Cataract surgery and intraocular lens implantation in children. Am J Ophthalmol 1995; 120:1-9. 19. Gimbel HV, DeBroff BM. Posterior capsulorhexis with optic capture: maintaining a clear visual axis after pediatric cataract surgery. J Cataract Refract Surg 1994;20:658-64.