Posterior Chamber Implants in Unilateral Congenital and Developmental Cataracts

Chirurgische Therapie der kongenitalen Katarakt

Due to the anatomical dimensions being smaller and the tissue structures being softer and more elastic in the young patient, surgery of paediatric cataracts represents a special challenge for the ophthalmic surgeon. Surgery is performed via a limbal or pars plana approach. The extreme high rate of secondary cataract formation in the paediatric or adolescent eye with closed posterior capsules is countered by means of complicated capsular surgery, special intraocular lens (IOL) implantation techniques, and vitreoretinal surgical procedures. It is customary not to implant IOLs before the children are 1-2 years old as increased axial length growth must be expected during the first 18 months after birth. IOL power is selected so that postoperative refraction is within the hyperopic range and with time, undercorrection will be balanced by bulbus growth. Preoperative and postoperative therapy is highly dependant on the extent of trauma sustained during surgery and should contain anti-inflammatory medication with and without steroids as well as antibiotics. Orthoptic follow-up examinations are also decisive for the long-term result.

Posterior chamber intraocular lens implantation in pediatric cataract with microcornea and/or microphthalmos

Purpose

To report the results of secondary posterior chamber intraocular lens (PC-IOL) implantation in pediatric cataract eyes with microcornea and/or microphthalmos.

Methods

Retrospective studies were conducted by reviewing the charts of 26 eyes of 15 patients with secondary PC-IOL implantations for microcornea and/or microphthalmos associated with cataract in children between 1999 and 2002. The corneal diameter was 9.5 mm or less at the time of secondary PC-IOL implantation. Preoperative examinations were conducted for bilaterality, corneal diameter, eye abnormalities and systemic abnormalities. Postoperative results were evaluated in terms of visual developments, refractive changes, axial length measurements and the occurrence of complications. The follow-up period was at least one year after secondary PC-IOL implantation.

Results

Age at the first diagnosis for cataract with microcornea and/or microphthalmos was 2.7 months on average. Among 15 patients, 8 (53.3%) had a family history. All patients received an initial irrigation and aspiration, posterior capsulectomy, and anterior vitrectomy at 0.8 years (0.1-3.3 years) of age and a secondary PC-IOL implantation surgery at 6.7 years (1.6-17.2 years) of age on average. The postoperative follow-up period was 2.1 years (1.1-4.3 years) on average. The average power of the implanted PC-IOL was +21.2D. Postoperative complications were secondary glaucoma in two eyes, secondary pupillary membrane formation in two eyes. Best corrected visual acuities in 20 eyes in children capable of the vision test at the last follow-up were 20/60 or better in 11 eyes, 20/80 to 20/150 in eight eyes, and 20/200 or worse in one eye.

Conclusions

The secondary PC-IOL implantation in pediatric cataract with microcornea and/or microphthalmos is recommended as a means of improving vision, but must be conducted carefully to avoid possible complications.

Intraocular lens implantation in a child with monocular cataract and anterior persistent hyperplastic primary vitreous

A 3-year-old girl had phacoemulsification during which the presence of anterior persistent hyperplastic primary vitreous (PHPV) was discovered. Visual rehabilitation comprised contact lens use for 1 year. However, visual acuity deteriorated gradually because of secondary cataract formation. In a second surgery 1 year after the first, the posterior capsule was incised, followed by an anterior vitrectomy and intraocular lens implantation. At the last follow-up 6 months after the second surgery, there was no evidence of ocular complications and best corrected visual acuity was 0.6.

Surgical management of congenital cataract associated with severe microphthalmos

PURPOSE

To report the results of cataract surgery in children with severe microphthalmos and congenital cataract.

SETTING

Seoul National University, Department of Ophthalmology, Seoul, Korea.

METHODS

Retrospective studies were conducted by reviewing the charts of 20 eyes of 11 patients with severe microcornea and microphthalmos or severe microcornea with a corneal diameter smaller than 9.0 mm. The patient pool was divided according to surgical method, specifically by incision site: an anterior group that had corneal limbal incisions and a posterior group treated via pars plicata incisions. Preoperative examinations included bilaterality, corneal diameter, axial length, and eye and systemic abnormalities. Postoperative results and complications of the 2 operative methods were compared.

RESULTS

All 11 patients had bilateral congenital cataract and microphthalmos. Except in 1 case, surgeries were done in patients ranging in age from 2 to 16 months. Mean follow-up was 2 years. Corneal diameter was smaller than 9.0 mm in all 20 eyes and smaller than 7.5 mm in 11 eyes. Ten eyes were categorized into the anterior group, and the other 10 eyes were placed in the posterior group. Postoperative complications included secondary membranes in 3 eyes in the posterior group and corneal opacity in 3 eyes in the anterior group.

CONCLUSION

The surgical management of children with congenital cataract and severe microphthalmos is recommended as a way to improve vision but must be performed carefully to avoid complications.

Intraocular lens implantation in children

Over the past 15 years, lens implant surgery in children has disseminated so much that it is no longer a controversial issue. It has become rather a specialized topic in the widespread field of lens implantation in the general population. To match the excellent results seen in adults, issues such as the surgical technique, the choice of the lens, and dioptric power of that lens, are constantly being refined and adapted to children's growing eyes. Scleral tunnels and small, self-sealing corneal incisions are being replicated in children to benefit from their advantages. Polymethyl methacrylate material remains unrivalled from the point of view of safety and longevity in the human eye. Intraocular lenses (IOLs) with an overall diameter of 12 mm can safely be used in nonmicrophthalmic eyes of children more than 3 years of age. Several investigators now recognize the need for smaller pediatric IOLs for neonates, toddlers, and microphthalmic eyes. Fortunately, modern IOLs are smaller today than they were 15 years ago. The accumulating evidence on the myopic shift that occurs in pseudophakic children have led to an almost unanimous agreement that the IOL power should aim for a certain amount of hypermetropia at time of surgery. The residual refractive error can be corrected with spectacle glasses that are adjusted throughout childhood. The goal is to start with hypermetropia in childhood that will convert into emmetropia or mild myopia in adulthood.

Does primary intraocular lens implantation prevent "aphakic" glaucoma in children?

PURPOSE

Open-angle glaucoma may develop after surgery for congenital or developmental cataract with an incidence ranging from 3% to 41%. The pathogenesis of "aphakic" (open-angle) glaucoma remains unknown. Despite numerous reported clinical series (>1000 eyes), we are unaware of any reported case of open-angle glaucoma after primary intraocular lens (IOL) implantation for congenital or developmental cataract. We decided to test the hypothesis that primary posterior chamber IOL implantation might decrease the incidence of open-angle glaucoma in children.

METHODS

Pseudophakic eyes were collected from surgeons who contributed data to a refractive study and who monitored intraocular pressure on a regular basis. IOL implantation was commonly performed in eyes with a corneal diameter >10 mm. Comparable primary data on aphakic eyes were included from 2 published studies on aphakic glaucoma, which included corneal diameters and the patient's age at surgery. Glaucoma-free survival estimates for each cohort were estimated.

RESULTS

Only 1 case of glaucoma was found among 377 eyes with primary pseudophakia (mean age of patient, 5.1 +/- 4.7 years; mean follow-up, 3.9 +/- 2.7 years). There were 14 eyes (11.3%) with glaucoma among 124 aphakic eyes (mean age of patient, 2.7 +/- 2.6 years; mean follow-up time, 7.2 +/- 3.9 years).

CONCLUSIONS

We report a decreased incidence of open-angle glaucoma among eyes rendered primarily pseudophakic compared with those that remained aphakic after cataract surgery. We propose 2 theories on the possible mechanism of reduction in the incidence of glaucoma in pseudophakic eyes.

A porcine model predicts that a can-opener capsulotomy can be done safely in pediatric patients

PURPOSE

The purpose of this study was to compare the strength and safety of a continuous circular capsulorhexis (CCC) with a can-opener capsulotomy (COC) in a porcine model that closely resembles the high elasticity of the human pediatric lens capsule.

METHODS

COCs (N = 47) and CCCs (N = 102) were performed inside the anterior chamber of fresh pig eyes, and any uncontrolled tears were noted. The circumference of the initial opening was measured in 18 COCs and 13 CCCs. After the opening was stretched to the point of rupture, the circumference was measured again. The ratio of the circumference at rupture to the initial circumference, minus one, was used as a measure of the maximal capsular strain.

RESULTS

The can-opener technique produced a smooth round opening. One of the COCs (2.1%) and 23 of the CCCs (22.5%) had uncontrolled tears (chi2, P<.001). The mean maximal strain for COCs was 46.7% (SE, 8.3%) and for the CCCs, 47.7% (SE, 9.9%). This difference was statistically not significant (P = .93 by Student's t test).

CONCLUSIONS

The porcine capsule is more reliably opened with fewer uncontrolled tears by a COC than by a CCC. The porcine model predicts that pediatric capsules can be opened safely with a COC.

The IOLAB, Inc pediatric intraocular lens study. AAPOS Reasearch Committee. American Association for Pediatric Ophthalmology and Strabismus

PURPOSE

This report is a summary of the data of the IOLAB, Inc pediatric intraocular lens (IOL) implantation investigation. The goal of this study was to evaluate the safety and efficacy of IOL implantation for the treatment of pediatric aphakia, pending approval by the Food and Drug Administration.

METHODS

From May 1981 to July 1994, a total of 1260 pediatric eyes received 171 styles of IOLs implanted by 361 US investigators. Preoperative, operative, and postoperative status reports over the first year were required for each eye entered into the study. Annual visit reports were requested thereafter to determine the long-term effects. The study was terminated in November 1995. All IOLs were obtained from IOLAB, Inc (now Chiron Vision Corp).

RESULTS

Reporting compliance was 98.3% for the preoperative and operative reports, 45.1% at 1 year, and 13.8% at 3 years. The subjects' ages ranged from younger than 1 yearto 17 years. Nine subjects (0.7%) were younger than 1 year, with the largest group of 533 subjects (42.3%) aged between 6 and 12 years atthe time of surgery. Cataract types were congenital (45.6%), traumatic (37.1%), secondary (11%), senile (0.95%), and unrecorded (5.4%). The IOL was implanted primarily in 74.8% of cases and secondarily in 21.4% of cases. There was no record in 3.8% of the cases. IOL types included anterior chamber (4.1%), iridocapsular (0.71%), posterior chamber (93.6%), and unrecorded (1.59%). There were 130 adverse reactions that required secondary surgical intervention. The most frequently performed surgical procedures included lens removal without replacement, vitrectomy, lens repositioning, and lens replacement. More than half (52%) of all eyes had a visual acuity of 20/200 or worse before surgery; amblyopia was reported in 21.1% of all participants at baseline. Postoperative visual acuity data were available on 563 eyes at 1 year after surgery. Overall, 52.8% of all eyes attained a visual acuity of 20/40 or better by the 1-year visit, and only 15.5% had visual acuity worse than 20/200. In general, the older patient, traumatic cataract, and secondary cataract categories were overrepresented in the better visual acuity outcome group.

CONCLUSION

The IOLAB, Inc pediatric IOL study is the first multiple-practitioner, national study designed to evaluate the safety and efficacy of IOL implantation in children. The study results are compromised by the almost 50% loss of follow-up at the 1-year evaluation. Other variables that most likely influenced outcome results were the methods of cataract extraction, medical management, and IOL design, all of which evolved dramatically over the time course of the study. Despite these issues, pediatric IOL implantation seems to be a reasonable treatment modality for aphakia, on the basis of the available 1-year follow-up data of the remaining 45.1% of eyes in the study.

Intraocular lens implantation in children and youth

PURPOSE

To evaluate the safety and the effectiveness posterior chamber intraocular lenses (PCIOLs) in children and youth with cataract.

METHODS

Retrospective study of operative and postoperative results was based on 146 eyes in 125 children ages 6 to 18 years (mean: 11.7 years) who underwent extracapsular cataract extraction with IOL implantation in the period from 1986 to 1996. Follow up was 1 to 10 years.

OUTCOME MEASURE

Best corrected distance and near visual acuity, operative complications, and early and late postoperative complications. Exclusion criteria were uveitis, retinal detachment, prior glaucoma, and systemic diseases.

RESULTS

Early postoperative complications were observed in 12.3% of cases including iritis in 7.5%, and transient corneal edema in 3.4% of eyes. Posterior capsule opacification requiring capsulotomy was needed in 81.5% of eyes after 8.5 years. YAG laser capsulotomy was performed in 68.1% and surgical intervention in 26.8% of cases. In 5.1% of the cases, both techniques were used. In 74.7% of patients, best corrected visual acuity of 0.5 or better was achieved. The mean postoperative spherical equivalent was +0.35 diopters (D, SD 1.35). Spectacle-corrected near visual acuity of 0.5 on the Snellen chart was obtained in 82.8% of eyes.

CONCLUSION

IOL implantation in children older than 6 years appears to be an efficacious, satisfactory, and safe procedure in the management of pediatric cataract.

Refractive status in children after long-term follow up of cataract surgery with intraocular lens implantation

PURPOSE

To evaluate the resultant refractive status in children 5 to 11 years after cataract surgery with a high power intraocular lens (IOL) implantation.

METHODS

Charts of eight patients (10 eyes) who underwent cataract surgery with IOL implantation by the same technique were reviewed. Age at surgery was 2 months to 3 years. High-power IOL of 27.0 to 30.0 diopters (D) was implanted in seven eyes and lower IOL (between 19.0 D to 23.0 D) in three eyes. Follow-up period was between 5 and 11 years.

RESULTS

In children who received a high-power IOL, the resultant refraction after 5 to 7 years was found to be between -5.50 and -12.00 D. In the group that had a lower power IOL implanted, the refraction was between -2.50 and +9.00 after 6 to 11 years. The results were plotted on a graph of refraction vs. IOL power and showed that the IOL power that may result in emmetropia in an older child is 23.2D.

CONCLUSIONS

The implantation of a high-power IOL (27 D to 30 D) in eight young children resulted in refractive status within 3 D of emmetropia during the first year or two of life and in high myopia at age 5 to 12 years.

Prospective evaluation of corneal endothelial cell loss after pediatric cataract surgery

PURPOSE

To study the alterations in endothelial cell count and morphology after pediatric cataract surgery using currently practiced techniques.

SETTING

L.V. Prasad Eye Institute, Hyderabad, India.

METHODS

In a prospective nonrandomized series comprising 20 eyes of 14 children with congenital or developmental cataract, endothelial cell loss from cataract surgery was evaluated. Mean patient age was 9.3 years (range 5 to 15 years). Extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation was performed in 11 eyes (Group 1). Primary posterior capsulotomy and anterior vitrectomy were performed with ECCE and IOL implantation in 9 eyes (Group 2). Noncontact specular microscopy was done preoperatively and 6 to 8 and 24 to 36 weeks postoperatively. Endothelial cell loss, alteration in the coefficient of variation, and the change in the number of hexagonal cells were determined by semiautomated analysis of endothelial pictures.

RESULTS

Mean endothelial cell loss was 198.39 cells/mm2 (5.28%) in Group 1 and 295.17 cells/mm2 (7.50%) in Group 2 at 24 to 36 weeks. There was no statistically significant difference in alteration in endothelial cell count and morphology between the 2 groups.

CONCLUSIONS

The results suggest that endothelial cell loss with currently practiced techniques of pediatric cataract surgery is within acceptable limits.

Results of bilateral cataract extraction with posterior chamber intraocular lens implantation in children

OBJECTIVE

A retrospective study was undertaken to evaluate long-term anatomic and visual outcomes in eyes of children who underwent bilateral intraocular lens implantation.

DESIGN

The study design was a review of medical records of 24 children operated on for bilateral cataracts and posterior chamber-intraocular lenses.

PARTICIPANTS

Twenty-four children operated on for bilateral cataracts by 1 surgeon between February 1980 and February 1995 were studied.

INTERVENTION

Cataract extraction with bilateral posterior chamber-intraocular lens implantation was performed.

MAIN OUTCOME MEASURES

Best-corrected visual acuity, visual acuity without correction, intraocular pressure, manifest refraction, and any intraoperative or postoperative complications were measured.

RESULTS

At last follow-up (mean follow-up, 50.8 months; range, 10-149 months), the intraocular lens was in good position and the intraocular pressure was normal without medication in all eyes. Four years after surgery, 79.2% (19 of 24) of first eyes achieved a best-corrected visual acuity of 20/40 or better compared to 66.7% (16 of 24) of second eyes. No eye had any loss in best-corrected visual acuity. In first eyes of 3- to 8-year olds at the time of surgery, 73.3% (11 of 15) achieved a spherical equivalent within 2 diopters of the intended at 4 years after surgery compared to 80% of second eyes. In the 9- to 18-year-old group, 88.9% (8 of 9) of first eyes and 100% of second eyes achieved a spherical equivalent within 2 diopters of the intended at 4 years after surgery. Intraoperative and postoperative complications were minimal.

CONCLUSIONS

Long-term anatomic and visual results have been gratifying in this series of patients with bilateral implants.

Pediatric cataract management with variations in surgical technique and aphakic optical correction

PURPOSE

The purpose of the study was to compare the results of three techniques of cataract surgery in children. Two methods included intraocular lens (IOL) implantation and one used contact lens correction of aphakia.

DESIGN

Nonrandomized clinical trial.

PARTICIPANTS

Seventy-seven eyes of 50 children between the ages of 2 1/2 and 16 years who had cataract surgery for the treatment of uncomplicated cataract.

INTERVENTION

Thirty-one eyes underwent a "conventional" style of implantation, and a "phaco-style" of surgery was used in 24 eyes. A contact lens was used as the primary means of aphakic correction in 22 eyes.

MAIN OUTCOME MEASURES

The visual results and complications of each type of surgery were compared.

RESULTS

Corrected visual acuities did not differ significantly between the three groups 6 months after surgery. The incidence and type of complications were significantly different. Better lens centration, less long-term iris changes, or wound-related problems were observed with "phaco-style" modification of the technique of IOL insertion.

CONCLUSIONS

Pediatric IOL insertion eliminated the need for contact lens wear and did not lead to a significantly different corrected visual acuity 6 months after surgery compared with lensectomy with contact lens correction. Adoption of some of the techniques of modern small-incision cataract surgery for pediatric IOL procedures produces a significant reduction in postoperative anterior segment complications compared with a standard limbal approach. Such modifications allow pediatric IOL insertion to be a safe alternative for the correction of pediatric aphakia.

Longitudinal changes in axial length in pseudophakic children

PURPOSE

To evaluate the axial length changes that occur in children 3 to 9 years of age who had cataract extraction with primary intraocular lens (IOL) implantation.

SETTING

Emory Eye Center, Emory University, and Egleston Children's Hospital, Atlanta, Georgia, USA.

METHODS

A review of 17 eyes in 15 children (mean age 6.4 years; range 3 to 9 years) who had primary IOL implantation was undertaken. Patients were followed for an average of 3.1 years. The initial and final axial length measurements and refractive errors were compared.

RESULTS

The overall change in mean axial length in the 17 eyes was 0.64 mm. The overall mean myopic shift was -1.01 diopters (D) (range -3.00 +0.50 D). Eyes with traumatic cataracts experienced more axial elongation than eyes with developmental/congenital cataracts (0.97 mm versus -0.01 mm; P = .03). Ninety-four percent of patients obtained a final visual acuity of 20/40 or better.

CONCLUSION

Eyes with traumatic cataracts experienced more axial elongation than eyes with developmental/congenital cataracts after cataract extraction and IOL implantation.

Choice of lens and dioptric power in pediatric pseudophakia

PURPOSE

To evaluate lens choice and dioptric power in pediatric eyes having posterior chamber intraocular lens (IOL) implantation.

SETTING

Oxford Eye Center and the St. John Eye Hospital, Johannesburg, South Africa.

METHODS

This retrospective study evaluated the refractive development in 156 pseudophakic eyes of 99 children aged 1 month to 8 years who had surgery between June 1983 and April 1994. The children were divided into three groups based on age at time of IOL implantation: Group A (68 eyes), 1 to 18 months; Group B (32 eyes), 19 to 36 months; Group C (48 eyes), 3 to 8 years. Poly(methyl methacrylate) posterior chamber IOLs with an overall diameter between 10.5 and 12.0 mm were used. The dioptric power was 3.00 to 6.00 diopters (D) less than that needed to achieve emmetropia.

RESULTS

In Group A, the mean growth in axial length was 3.59 mm +/- 1.80 (SD) and the mean change in refraction was 6.39 +/- 3.68 D. In Group B, the respective means were 0.75 +/- 0.85 mm and 2.73 +/- 1.40 D and in Group C, 0.76 +/- 0.69 mm and 2.60 +/- 1.84 D.

CONCLUSIONS

The younger the child at time of implantation, the greater the myopic shift. To reduce the necessity of IOL exchange, these eyes should be undercorrected, with the residual refractive error corrected by spectacles that are adjusted throughout life according to refractive development. This leads to initial hypermetropia that gradually moves to emmetropia or moderate myopia in adulthood.

Unilateral pseudophakia in children under 4 years

PURPOSE

We examined the efficacy of intraocular lens implantation (IOL) in children younger than 4 years of age for unilateral aphakic visual rehabilitation.

METHODS

Twenty-one patients underwent unilateral cataract extraction, IOL placement, posterior capsulotomy, and anterior vitrectomy between 1990 and 1994. Postoperative vision, refractive change, and complications were monitored prospectively. Two cataract subgroups were analyzed: 12 patients with infantile (congenital and developmental) cataracts, and nine patients with posttraumatic cataracts.

RESULTS

Overall age at surgery averaged 26 months (range 9 to 44 months), with follow up of 5 to 55 months. Fifty-two percent achieved 20/40 or better vision: 42% in the infantile group and 67% in the traumatic group. IOL power averaged 22.6 diopters (D). The difference between predicted and actual postoperative refraction was less than 1 D in 70%. After 6 months, the average change in refraction was 0.50 D (21 patients). An increasing myopic shift of 1.10 D at 12 months (14 patients), 1.80 D at 18 months (nine patients), and 2.90 D after 24 months (eight patients) was noted. This trend was greater in the infantile group. Amblyopia treatment was implemented in 18 patients. Half have completed occlusion successfully, one third continue therapy, 17% are treatment failures, and 11% (two patients) were lost to follow up. Six patients required strabismus surgery; five had infantile cataracts. Postoperative complications occurred in four eyes, two infantile and two traumatic; they consisted of posttraumatic temporal IOL dislocation, corectopia, partial pupillary capture of an IOL, and partial pupillary membrane.

CONCLUSION

Primary IOL implantation is an effective way to rapidly achieve aphakic visual rehabilitation in preschool children. We continue to evaluate the long-term safety and effects of pediatric pseudophakia.

Outcome and complications of intraocular lenses in children with cataract

PURPOSE

To assess prospectively the complications and changes in refraction, axial length, and keratometry after intraocular lens (IOL) implantation in children with congenital, developmental, and traumatic cataracts.

SETTING

The Children's Hospital, Dublin, Ireland.

METHODS

The study comprised 24 eyes of 20 patients, aged 4 weeks to 12 years, who had extracapsular cataract extraction and posterior chamber IOL implantation. Mean follow-up was 103 weeks (range 34 to 270 weeks).

RESULTS

Six eyes with congenital cataracts operated on between 4 and 28 weeks of age had central, steady, maintained fixation postoperatively. In the developmental cataract group, 64% achieved a visual acuity of 6/24 or better and 43%, 6/12 or better. In the three traumatic cases, visual acuities were 6/6, 6/9, and 6/24. Posterior capsule opacification occurred in 95.8% of eyes and was treated with a neodymium: YAG or Zeigler knife posterior capsulotomy as a secondary procedure. Other postoperative complications (membranous uveitis, iris capture, posterior synechias, iris prolapse) occurred in 29.2% of eyes.

CONCLUSION

With careful management and patient selection, the use of IOLs in children can produce good visual results with a minimum of complications. Further follow-up is needed to assess the long-term visual outcome, complications, and changes in refraction.

Intraocular lens implantation in children in the West Bank and Gaza

In order to evaluate the efficacy and safety of intraocular lens (IOL) implantation in paediatric aphakia, we reviewed the records of a consecutive series of 40 children, under 15 years of age, who had IOLs inserted for congenital and developmental cataracts between September 1990 and December 1992. Visual results and lens-induced complications were evaluated in 67 eyes with a mean follow-up of 27 months (range 12-38 months). In 52 eyes the cataract was removed by limbal lens aspiration and in 15 eyes by pars plicata lens aspiration. One-piece PMMA Sinskey-type posterior chamber implants were used in all cases. Sixty-three eyes had primary and 4 eyes secondary implants. Seventeen (49%) of 35 eyes with congenial cataract and 25 (78%) of 32 eyes with developmental cataract achieved a visual acuity of 6/18 or better. Marked anterior uveitis with pupillary membrane formation occurred in 9 (13%) of the 67 eyes. Visually significant posterior capsule opacification occurred in 5 (28%) of the 18 eyes with intact capsule. Our results demonstrate the suitability of IOL implantation in children from an area of low socioeconomic background, and suggest that IOL implantation is an effective and safe procedure for correction of paediatric aphakia. This may have implications for similar populations.

Intraocular lens implantation in infants with congenital cataracts

We evaluated 21 eyes of 13 infants between two and eight months old who had primary posterior chamber intraocular lens (IOL) implantation for congenital cataracts between 1988 and 1993. Twelve eyes had a posterior capsulorhexis or plaque peeling at the time of implantation and one eye had a vitrectomy. Eight eyes had no posterior capsule procedure during the initial surgery. Follow-up ranged from six months to five years. All eyes developed one or multiple posterior synechias and all, except one, required secondary capsulectomy and vitrectomy between one month and one year. Twenty eyes attained stable IOL fixation and a clear visual axis. In one eye, the IOL decentered downward. Patients with bilateral cataracts had greater visual improvement than those with a cataract in one eye only. No patient could manage spectacles postoperatively. Our findings show the benefits of posterior capsulectomy and anterior vitrectomy done in the early postoperative period and that IOL implantation in infants is a reasonable treatment in some parts of the world.

Implantation in children

With the development of posterior chamber lenses and continuous curvilinear capsulorhexis, and with the availability of viscoelastic agents, the use of intraocular lenses (IOLs) in children is becoming more popular. Since 1982, we have implanted posterior chamber IOLs (PC-IOLs) in the capsular bags of 61 cataractous eyes of 46 children and adolescents. The goal was in-the-bag placement facilitated by the use of a small capsulectomy, and, since 1984, by the use of the continuous curvilinear capsulorhexis. Forty-four cataracts were congenital, 13 were traumatic, and 4 were developmental. Cataract extraction with IOL implantation was performed in 16 (26%) preschool cases (ages 2 through 5), in 31 (51%) child cases (ages 6 through 12), and 14 (23%) adolescent cases (ages 13 through 18). Surgical and postoperative complications were minimal. Visual results were good. Fifty-six percent of preschoolers, 87% of children, and 86% of adolescents achieved 20/40 or better best corrected vision, with 79% of the total cohort achieving 20/40 or better. Overall, 35% achieved an uncorrected visual acuity of 20/40 or better. All but two cases had improvement in best corrected vision; if 20/20 was not attained, the cause was mainly due to deprivation amblyopia. Forty-eight percent of patients were within a diopter of emmetropia.

Results of intraocular lens implantation in paediatric aphakia

Intraocular lenses were implanted in 16 eyes of 13 patients with congenital cataract, and visual progress was plotted using a preferential-looking technique. Initial surgery was by lens aspiration with preservation of the posterior capsule, and subsequent posterior capsulotomy without anterior vitrectomy. Poly-HEMA posterior chamber lenses were used, usually as a primary procedure but in four cases as a secondary procedure after contact lens failure. No serious complications were encountered. Most eyes achieved a very significant visual improvement, and none were worse than preoperatively. Residual refractive error was highly unpredictable, but did not exceed 6 dioptres. The importance of rigorous occlusion therapy is stressed. With close follow-up, this procedure offers an effective and safe method for the correction of unilateral paediatric aphakia, and, in selected cases only, for bilateral aphakia.