- Email: [email protected]
Pediatric cataract surgery with or without anterior vitrectomy
Pediatric cataract surgery with or without anterior vitrectomy Maria Kugelberg, MD, Charlotta Zetterstro¨m, MD, PhD Purpose: To evaluate after-cataract formation in children having cataract surgery with or without dry anterior vitrectomy and possible differences according to age. Setting: St. Erik’s Eye Hospital, Stockholm, Sweden. Methods: This retrospective study comprised 85 eyes of 85 patients from 0 to 15 years old who had cataract surgery with or without anterior vitrectomy after the implantation of an intraocular lens (IOL). All patients had primary posterior capsulorhexis but no optic capture. Thirty-five patients received a heparin-surface-modified poly(methyl methacrylate) IOL (809C, Pharmacia & Upjohn) and 50 patients, a foldable acrylic IOL (AcrySof姞, Alcon). The records from follow-up visits at the patients’ home clinics were used for analysis. Results: Significantly fewer children were operated on for after-cataract if they had cataract surgery with anterior vitrectomy (P ⬍ .05). This applied to both IOL types. In the children older than 7 years in the AcrySof IOL group, there was no difference in the frequency of after-cataract surgery (P ⬎ .05). In children younger than 7 years with an AcrySof IOL, the rate of after-cataract surgery was significantly less in those who had an anterior vitrectomy at the time of cataract surgery (P ⬍ .05). Conclusion: In younger children, it is advantageous to perform cataract surgery with anterior vitrectomy to help prevent after-cataract formation; however, vitrectomy is not necessary in older children. J Cataract Refract Surg 2002; 28:1770 –1773 © 2002 ASCRS and ESCRS
Y
oung children with dense cataract need surgery promptly to avoid amblyopia.1 After 1 to 2 years of age, most children receive an intraocular lens (IOL), with favorable results.2,3 Implantation of an IOL decreases after-cataract formation.4,5 However, there is also a high incidence of after-cataract formation in these patients,2 which increases the risk of irreversible amblyopia. For cataract surgery in children, many surgeons perform a posterior continuous curvilinear capsulorhexis (PCCC) to stop lens epithelial cells (LECs), which form the after-cataract, from growing on the posterior lens capsule.6 Despite this step, small children often develop after-cataract because the LECs grow on the anterior Accepted for publication January 30, 2002. Reprint requests to Maria Kugelberg, MD, St. Erik’s Eye Hospital, 112 82 Stockholm, Sweden. E-mail: [email protected]. © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
surface of the vitreous. To hinder the LECs from proliferating onto the vitreous surface, an anterior vitrectomy can be performed from the pars plana, after a pars plana posterior capsulotomy,7 or through limbal incisions.8 This retrospective study evaluated the incidence of after-cataract in 85 children who had cataract surgery with or without dry anterior vitrectomy directly after IOL implantation.
Patients and Methods Between 1997 and 2000, 85 children younger than 15 years of age had cataract surgery with IOL implantation by the same surgeon (C.Z.) at St. Erik’s Eye Hospital, Stockholm, Sweden. The median age of the children was 68 months (range 2 to 182 months). Of the children with bilateral cataract who had surgery in both eyes, only the first operated eye was included for statistical reasons. Thirty-five eyes received a heparin-surface-modified poly(methyl methacrylate) (HSM 0886-3350/02/$–see front matter PII S0886-3350(02)01332-9
PEDIATRIC CATARACT SURGERY AND ANTERIOR VITRECTOMY
Figure 1. (Kugelberg) Results in a 2 ⫻ 2 table in children with an
Figure 2. (Kugelberg) Results in a 2 ⫻ 2 table in children with an
HSM PMMA IOL. The figures in the table are the number of patients.
AcrySof IOL. The figures in the table are the number of patients.
PMMA) IOL 809C (Pharmacia & Upjohn) and 50 eyes, an AcrySof威 MA30BA foldable acrylic IOL (Alcon). All children had general anesthesia. One hour before surgery, pupils were dilated with a combination of cyclopentolate 0.85% and phenylephrine 1.5%. The drops were given 3 times with 5 minutes between. A 2.8 mm scleral incision was made, sodium hyaluronate 1.4% (Healon GV威) was injected into the anterior chamber, and an anterior continuous curvilinear capsulorhexis was created with a needle and capsulorhexis forceps. The nucleus was hydrodissected, and irrigation/aspiration was performed in the posterior chamber. A PCCC slightly smaller than the anterior capsulorhexis was made with a needle and forceps, and an HSM PMMA or AcrySof IOL was implanted in the capsular bag. For the HSM PMMA IOL, the incision was widened to 5.0 mm and for the AcrySof IOL, to 3.4 mm. In approximately half the patients, a dry anterior vitrectomy was performed after IOL implantation, with Healon GV remaining in the anterior chamber. Care was taken not to leave any vitreous strands when removing the vitrectomy probe. Acetylcholine chloride (Miochol威) was injected into the anterior chamber to close the pupil and ensure there were no vitreous strands to the port. The scleral incision was closed by a continuous 10-0 nylon suture. Next, 1 mg of cefuroxime sodium (Zinacef威) was injected into the anterior chamber. After surgery, the children received dexamethasone 1% eyedrops 3 times a day for the first week, 2 times a day for the second week, and once a day for the third week. Postoperative examinations were performed at St. Erik’s Eye Hospital after 1 day. After that, the examinations were
performed at the child’s home clinic. The records of the visits were sent from the home clinics and evaluated for the incidence of after-cataract. The median follow-up was 19 months (range 4 to 39 months). The results were analyzed using the Fisher exact test with 2 ⫻ 2 tables and a 1-way test.
Figure 3. (Kugelberg) Results in a 2 ⫻ 2 table in the younger half of patients with an AcrySof IOL. The figures in the table are the number of patients.
Results Significantly more patients had surgery for aftercataract if they did not have an anterior vitrectomy at the time of cataract surgery. This was significant for both IOL types (P ⬍ .05) (Figures 1 and 2). No retinal complications such as retinal detachment or cystoid macular edema (CME) were seen postoperatively. The children with an AcrySof lens, which was the largest group, were divided into older and younger. The division between the two halves was 7 years. In the younger half, statistically significantly more patients had surgery for after-cataract if they did not have an anterior vitrectomy (P ⬍ .05) (Figure 3). In the older group, however, there was no significant difference in aftercataract frequency with or without an anterior vitrectomy (P ⬎ .05) (Figure 4).
Discussion Our retrospective study shows that it is favorable to perform PCCC with anterior vitrectomy in small chil-
Figure 4. (Kugelberg) Results in a 2 ⫻ 2 table in the older half of patients with an AcrySof IOL. The figures in the table are the number of patients.
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PEDIATRIC CATARACT SURGERY AND ANTERIOR VITRECTOMY
dren, but in older children an anterior vitrectomy is not necessary. The management of the posterior capsule and the question of whether to perform an anterior vitrectomy during cataract surgery in children are controversial and have been discussed in many articles. Studies report different results. An earlier prospective study found that anterior vitrectomy should be performed in children younger than 5 years.8 However, older children were not included in that study, so it is unclear whether all children should have an anterior vitrectomy based on these results. Also, some patients had optic capture. In a retrospective study, Koch and Kohnen9 showed that PCCC with anterior vitrectomy was the only effective method of preventing secondary cataract formation in children. In the study, no patient having a anterior vitrectomy developed after-cataract; all but 1 eye in the other treatment groups developed after-cataract. However, the study included relatively few patients and the patients were between 1.5 and 12.0 years old with no separation according to age. Zetterstro¨ m and coauthors10 report that PCCC with no anterior vitrectomy is sufficient; however, the follow-up was only 4 to 16 months. The present study included both older and younger children and had a longer follow-up. Many techniques have been described to prevent after-cataract. One is PCCC with optic capture but no anterior vitrectomy.11,12 However, Vasavada and coauthors13 recently showed the necessity of vitrectomy when optic capture is performed to keep a clear visual axis in children between 5 years and 12 years. In another study, 4 of 5 eyes that had optic capture but no vitrectomy developed after-cataract.9 A recent study concluded that PCCC and anterior vitrectomy in children provide good visual rehabilitation.14 In 1 study in which a PCCC was performed with no anterior vitrectomy,15 the incidence of posterior capsule opacification requiring capsulotomy was 15.6% over a mean follow-up of 19 months. The need for vitrectomy was questioned, but it was also stated that no complications such as retinal detachment have been reported in children. In a questionnaire answered by more than 1000 cataract surgeons in the United States,6 many surgeons said they perform a pars plana vitrectomy/ membranectomy after repeat neodymium:YAG laser openings closed. In a prospective study including 192 children, there were no significant differences in postop1772
erative complications such as endophthalmitis, IOL dislocation, or retinal detachment if patients had only lensectomy and IOL implantation, lensectomy and anterior vitrectomy, or lensectomy, PCCC, anterior vitrectomy, and IOL implantation.16 In our study, there were no postoperative complications such as retinal detachment or CME. It therefore seems safe to perform an anterior vitrectomy during cataract surgery. In our study, some patients with an HSM PMMA IOL developed after-cataract even though surgery was performed with an anterior vitrectomy. Six of 31 patients who had anterior vitrectomy had to have surgery for after-cataract. Also, as many as 3 of 4 children who did not have an anterior vitrectomy developed aftercataract. Of the children with an AcrySof IOL, none who had an anterior vitrectomy developed after-cataract; 8 of 31 patients who did not have an anterior vitrectomy developed after-cataract. These results suggest that the AcrySof is a better choice of IOL in the pediatric patients in terms of after-cataract. In conclusion, our results indicate that cataract surgery with anterior vitrectomy helps prevent after-cataract in younger children, especially when an AcrySof IOL is implanted. In older children, anterior vitrectomy is not necessary. It is impossible to say exactly at what age anterior vitrectomy should not be performed, a topic that requires evaluation in a prospective randomized study.
References 1. Dutton JJ, Baker JD, Hiles DA, Morgan KS. Viewpoints: visual rehabilitation of aphakic children. Surv Ophthalmol 1990; 34:365–384 2. Zwaan J, Mullaney PB, Awad A, et al. Pediatric intraocular lens implantation; surgical results and complications in more than 300 patients. Ophthalmology 1998; 105: 112–118; discussion by RM Robb, 118 –119 3. Cavallaro BE, Madigan WP, O’Hara MA, et al. Posterior chamber intraocular lens use in children. J Pediatr Ophthalmol Strabismus 1998; 35:254 –263 4. Nishi O. Incidence of posterior capsule opacification in eyes with and without posterior chamber intraocular lenses. J Cataract Refract Surg 1986; 12:519 –522 5. Zetterstro¨ m C, Kugelberg U, Lundgren B, Syre´n-Nordqvist S. After-cataract formation in newborn rabbits implanted with intraocular lenses. J Cataract Refract Surg 1996; 22:85–88 6. Wilson ME, Bluestein EC, Wang X-H. Current trends in
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
PEDIATRIC CATARACT SURGERY AND ANTERIOR VITRECTOMY
7.
8.
9.
10.
11.
12.
the use of intraocular lenses in children. J Cataract Refract Surg 1994; 20:579 –583 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 Vasavada A, Desai J. Primary posterior capsulorhexis with and without anterior vitrectomy in congenital cataracts. J Cataract Refract Surg 1997; 23:645–651 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 Zetterstro¨ m 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 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 –664 Gimbel HV. Posterior continuous curvilinear capsulo-
13.
14. 15.
16.
rhexis and optic capture of the intraocular lens to prevent secondary opacification in pediatric cataract surgery. J Cataract Refract Surg 1997; 23:652–656 Vasavada AR, Trivedi RH, Singh R. Necessity of vitrectomy when optic capture is performed in children older than 5 years. J Cataract Refract Surg 2001; 27:1185– 1193 Ahmadieh H, Javadi MA. Intra-ocular lens implantation in children. Curr Opin Ophthalmol 2001; 12:30 –34 Fenton S, O’Keefe M. Primary posterior capsulorhexis without anterior vitrectomy in pediatric cataract surgery: longer term outcome. J Cataract Refract Surg 1999; 25: 763–767 Basti S, Ravishankar U, Gupta S. Results of a prospective evaluation of three methods of management of pediatric cataracts. Ophthalmology 1996; 103:713–720
From St. Erik’s Eye Hospital, Stockholm, Sweden. Supported by Margit Thyselius fond fo¨r blind ungdom, Sweden. Neither author has a financial or proprietary interest in any material or method mentioned.
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
1773
Y
oung children with dense cataract need surgery promptly to avoid amblyopia.1 After 1 to 2 years of age, most children receive an intraocular lens (IOL), with favorable results.2,3 Implantation of an IOL decreases after-cataract formation.4,5 However, there is also a high incidence of after-cataract formation in these patients,2 which increases the risk of irreversible amblyopia. For cataract surgery in children, many surgeons perform a posterior continuous curvilinear capsulorhexis (PCCC) to stop lens epithelial cells (LECs), which form the after-cataract, from growing on the posterior lens capsule.6 Despite this step, small children often develop after-cataract because the LECs grow on the anterior Accepted for publication January 30, 2002. Reprint requests to Maria Kugelberg, MD, St. Erik’s Eye Hospital, 112 82 Stockholm, Sweden. E-mail: [email protected]. © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
surface of the vitreous. To hinder the LECs from proliferating onto the vitreous surface, an anterior vitrectomy can be performed from the pars plana, after a pars plana posterior capsulotomy,7 or through limbal incisions.8 This retrospective study evaluated the incidence of after-cataract in 85 children who had cataract surgery with or without dry anterior vitrectomy directly after IOL implantation.
Patients and Methods Between 1997 and 2000, 85 children younger than 15 years of age had cataract surgery with IOL implantation by the same surgeon (C.Z.) at St. Erik’s Eye Hospital, Stockholm, Sweden. The median age of the children was 68 months (range 2 to 182 months). Of the children with bilateral cataract who had surgery in both eyes, only the first operated eye was included for statistical reasons. Thirty-five eyes received a heparin-surface-modified poly(methyl methacrylate) (HSM 0886-3350/02/$–see front matter PII S0886-3350(02)01332-9
PEDIATRIC CATARACT SURGERY AND ANTERIOR VITRECTOMY
Figure 1. (Kugelberg) Results in a 2 ⫻ 2 table in children with an
Figure 2. (Kugelberg) Results in a 2 ⫻ 2 table in children with an
HSM PMMA IOL. The figures in the table are the number of patients.
AcrySof IOL. The figures in the table are the number of patients.
PMMA) IOL 809C (Pharmacia & Upjohn) and 50 eyes, an AcrySof威 MA30BA foldable acrylic IOL (Alcon). All children had general anesthesia. One hour before surgery, pupils were dilated with a combination of cyclopentolate 0.85% and phenylephrine 1.5%. The drops were given 3 times with 5 minutes between. A 2.8 mm scleral incision was made, sodium hyaluronate 1.4% (Healon GV威) was injected into the anterior chamber, and an anterior continuous curvilinear capsulorhexis was created with a needle and capsulorhexis forceps. The nucleus was hydrodissected, and irrigation/aspiration was performed in the posterior chamber. A PCCC slightly smaller than the anterior capsulorhexis was made with a needle and forceps, and an HSM PMMA or AcrySof IOL was implanted in the capsular bag. For the HSM PMMA IOL, the incision was widened to 5.0 mm and for the AcrySof IOL, to 3.4 mm. In approximately half the patients, a dry anterior vitrectomy was performed after IOL implantation, with Healon GV remaining in the anterior chamber. Care was taken not to leave any vitreous strands when removing the vitrectomy probe. Acetylcholine chloride (Miochol威) was injected into the anterior chamber to close the pupil and ensure there were no vitreous strands to the port. The scleral incision was closed by a continuous 10-0 nylon suture. Next, 1 mg of cefuroxime sodium (Zinacef威) was injected into the anterior chamber. After surgery, the children received dexamethasone 1% eyedrops 3 times a day for the first week, 2 times a day for the second week, and once a day for the third week. Postoperative examinations were performed at St. Erik’s Eye Hospital after 1 day. After that, the examinations were
performed at the child’s home clinic. The records of the visits were sent from the home clinics and evaluated for the incidence of after-cataract. The median follow-up was 19 months (range 4 to 39 months). The results were analyzed using the Fisher exact test with 2 ⫻ 2 tables and a 1-way test.
Figure 3. (Kugelberg) Results in a 2 ⫻ 2 table in the younger half of patients with an AcrySof IOL. The figures in the table are the number of patients.
Results Significantly more patients had surgery for aftercataract if they did not have an anterior vitrectomy at the time of cataract surgery. This was significant for both IOL types (P ⬍ .05) (Figures 1 and 2). No retinal complications such as retinal detachment or cystoid macular edema (CME) were seen postoperatively. The children with an AcrySof lens, which was the largest group, were divided into older and younger. The division between the two halves was 7 years. In the younger half, statistically significantly more patients had surgery for after-cataract if they did not have an anterior vitrectomy (P ⬍ .05) (Figure 3). In the older group, however, there was no significant difference in aftercataract frequency with or without an anterior vitrectomy (P ⬎ .05) (Figure 4).
Discussion Our retrospective study shows that it is favorable to perform PCCC with anterior vitrectomy in small chil-
Figure 4. (Kugelberg) Results in a 2 ⫻ 2 table in the older half of patients with an AcrySof IOL. The figures in the table are the number of patients.
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
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PEDIATRIC CATARACT SURGERY AND ANTERIOR VITRECTOMY
dren, but in older children an anterior vitrectomy is not necessary. The management of the posterior capsule and the question of whether to perform an anterior vitrectomy during cataract surgery in children are controversial and have been discussed in many articles. Studies report different results. An earlier prospective study found that anterior vitrectomy should be performed in children younger than 5 years.8 However, older children were not included in that study, so it is unclear whether all children should have an anterior vitrectomy based on these results. Also, some patients had optic capture. In a retrospective study, Koch and Kohnen9 showed that PCCC with anterior vitrectomy was the only effective method of preventing secondary cataract formation in children. In the study, no patient having a anterior vitrectomy developed after-cataract; all but 1 eye in the other treatment groups developed after-cataract. However, the study included relatively few patients and the patients were between 1.5 and 12.0 years old with no separation according to age. Zetterstro¨ m and coauthors10 report that PCCC with no anterior vitrectomy is sufficient; however, the follow-up was only 4 to 16 months. The present study included both older and younger children and had a longer follow-up. Many techniques have been described to prevent after-cataract. One is PCCC with optic capture but no anterior vitrectomy.11,12 However, Vasavada and coauthors13 recently showed the necessity of vitrectomy when optic capture is performed to keep a clear visual axis in children between 5 years and 12 years. In another study, 4 of 5 eyes that had optic capture but no vitrectomy developed after-cataract.9 A recent study concluded that PCCC and anterior vitrectomy in children provide good visual rehabilitation.14 In 1 study in which a PCCC was performed with no anterior vitrectomy,15 the incidence of posterior capsule opacification requiring capsulotomy was 15.6% over a mean follow-up of 19 months. The need for vitrectomy was questioned, but it was also stated that no complications such as retinal detachment have been reported in children. In a questionnaire answered by more than 1000 cataract surgeons in the United States,6 many surgeons said they perform a pars plana vitrectomy/ membranectomy after repeat neodymium:YAG laser openings closed. In a prospective study including 192 children, there were no significant differences in postop1772
erative complications such as endophthalmitis, IOL dislocation, or retinal detachment if patients had only lensectomy and IOL implantation, lensectomy and anterior vitrectomy, or lensectomy, PCCC, anterior vitrectomy, and IOL implantation.16 In our study, there were no postoperative complications such as retinal detachment or CME. It therefore seems safe to perform an anterior vitrectomy during cataract surgery. In our study, some patients with an HSM PMMA IOL developed after-cataract even though surgery was performed with an anterior vitrectomy. Six of 31 patients who had anterior vitrectomy had to have surgery for after-cataract. Also, as many as 3 of 4 children who did not have an anterior vitrectomy developed aftercataract. Of the children with an AcrySof IOL, none who had an anterior vitrectomy developed after-cataract; 8 of 31 patients who did not have an anterior vitrectomy developed after-cataract. These results suggest that the AcrySof is a better choice of IOL in the pediatric patients in terms of after-cataract. In conclusion, our results indicate that cataract surgery with anterior vitrectomy helps prevent after-cataract in younger children, especially when an AcrySof IOL is implanted. In older children, anterior vitrectomy is not necessary. It is impossible to say exactly at what age anterior vitrectomy should not be performed, a topic that requires evaluation in a prospective randomized study.
References 1. Dutton JJ, Baker JD, Hiles DA, Morgan KS. Viewpoints: visual rehabilitation of aphakic children. Surv Ophthalmol 1990; 34:365–384 2. Zwaan J, Mullaney PB, Awad A, et al. Pediatric intraocular lens implantation; surgical results and complications in more than 300 patients. Ophthalmology 1998; 105: 112–118; discussion by RM Robb, 118 –119 3. Cavallaro BE, Madigan WP, O’Hara MA, et al. Posterior chamber intraocular lens use in children. J Pediatr Ophthalmol Strabismus 1998; 35:254 –263 4. Nishi O. Incidence of posterior capsule opacification in eyes with and without posterior chamber intraocular lenses. J Cataract Refract Surg 1986; 12:519 –522 5. Zetterstro¨ m C, Kugelberg U, Lundgren B, Syre´n-Nordqvist S. After-cataract formation in newborn rabbits implanted with intraocular lenses. J Cataract Refract Surg 1996; 22:85–88 6. Wilson ME, Bluestein EC, Wang X-H. Current trends in
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
PEDIATRIC CATARACT SURGERY AND ANTERIOR VITRECTOMY
7.
8.
9.
10.
11.
12.
the use of intraocular lenses in children. J Cataract Refract Surg 1994; 20:579 –583 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 Vasavada A, Desai J. Primary posterior capsulorhexis with and without anterior vitrectomy in congenital cataracts. J Cataract Refract Surg 1997; 23:645–651 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 Zetterstro¨ m 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 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 –664 Gimbel HV. Posterior continuous curvilinear capsulo-
13.
14. 15.
16.
rhexis and optic capture of the intraocular lens to prevent secondary opacification in pediatric cataract surgery. J Cataract Refract Surg 1997; 23:652–656 Vasavada AR, Trivedi RH, Singh R. Necessity of vitrectomy when optic capture is performed in children older than 5 years. J Cataract Refract Surg 2001; 27:1185– 1193 Ahmadieh H, Javadi MA. Intra-ocular lens implantation in children. Curr Opin Ophthalmol 2001; 12:30 –34 Fenton S, O’Keefe M. Primary posterior capsulorhexis without anterior vitrectomy in pediatric cataract surgery: longer term outcome. J Cataract Refract Surg 1999; 25: 763–767 Basti S, Ravishankar U, Gupta S. Results of a prospective evaluation of three methods of management of pediatric cataracts. Ophthalmology 1996; 103:713–720
From St. Erik’s Eye Hospital, Stockholm, Sweden. Supported by Margit Thyselius fond fo¨r blind ungdom, Sweden. Neither author has a financial or proprietary interest in any material or method mentioned.
J CATARACT REFRACT SURG—VOL 28, OCTOBER 2002
1773