Intraocular lens designed for the newborn infant eye

Primary intraocular lens implantation in infants: complications and visual results

PURPOSE

To evaluate the complications and visual results in a consecutive series of patients having cataract extraction with intraocular lens (IOL) implantation in the first year of life.

SETTING

St. Erik's Eye Hospital, Stockholm, Sweden.

METHODS

This retrospective study comprised 28 children (31 eyes) who had cataract surgery with primary IOL implantation.

RESULTS

The median age at surgery was 2.5 months (range 8 days to 10 months). The median follow-up was 36 months. Two newborns with persistent fetal vasculature (PFV) who had surgery at 8 days and 17 days, respectively, developed intraoperative vitreous hemorrhage; a retinal detachment developed in 1 of the eyes. Intraocular lens luxation occurred in 2 infants with PFV. Seventy percent of eyes developed opacification of the visual axis that required additional surgery. Chronic glaucoma developed in 2 eyes and transitory glaucoma in 1 eye. Two of the glaucoma cases occurred in eyes with PFV. In 7 eyes of 4 infants with bilateral cataract, the median visual acuity was 20/63 (range 20/25 to 20/100). In 12 infants with unilateral cataract without PFV, 7 achieved a visual acuity between 20/32 and 20/200 (median 20/63), 4 achieved counting fingers (CF), and 1 achieved light perception. In 12 eyes with PFV, 2 achieved a visual acuity of 20/200 and the rest achieved CF or worse.

CONCLUSIONS

After-cataract with membrane formation was the main complication in infants with primary IOL implantation. The glaucoma incidence was low at the last follow-up.

Single-piece AcrySof intraocular lens implantation in children with congenital and developmental cataract

PURPOSE

To evaluate surgical outcomes of 1-piece AcrySof SA30AL intraocular lens (IOL) (Alcon Laboratories) implantation in children having surgery for congenital and developmental cataracts.

SETTING

Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India.

METHODS

This prospective observational study comprised 134 consecutive eyes of 84 children from 2 to 15 years old who had surgery for congenital and developmental cataract. Two groups were formed depending on the age of the child at surgery. Primary posterior continuous curvilinear capsulorhexis (PCCC) was performed in children younger than 6 years (Group 1, 66 eyes), and no PCCC was performed in children older than 6 years (Group 2, 68 eyes). Vitrectomy was not performed. An AcrySof IOL was implanted in the bag in all eyes except 1 in Group 1, which received a sulcus-fixated IOL. The study's primary outcome measures were the incidence of visual axis obscuration and the need for a secondary procedure to clear the axis. Secondary observations included the incidence of posterior synechias, cell deposits, and haptic compression. A test of proportion was applied to determine whether age was a risk factor for the development of visual axis obscuration.

RESULTS

The mean age at surgery was 6.0 years +/- 3.2 (SD). The mean follow-up was 2.6 +/- 0.6 years. In Group 1, 20 eyes (30.3%) developed visual axis obscuration but only 6 (9.1%) required a secondary procedure. In Group 2, 20 eyes (29.4%) developed visual axis obscuration and 10 (14.7%) required secondary procedures. Posterior synechias were observed in 2 eyes (3.0%) in Group 1 and none in Group 2. Cell deposits were seen in 8 eyes (12.1%) in Group 1 and 8 eyes (11.8%) in Group 2. Haptic compression was noted in 1 eye in Group 2. Mild IOL decentration was observed in the 1 eye with a sulcus-fixated IOL.

CONCLUSION

The 1-piece AcrySof IOL provided satisfactory visual axis clarity, produced an acceptable inflammatory response, and maintained centration in pediatric eyes.

Cataracts in children

Bilateral congenital cataract is the most common cause of treatable childhood blindness. Nuclear cataract is usually present at birth and is nonprogressive, whereas lamellar cataract usually develops later and is progressive. Surgery must be performed promptly in cases with dense congenital cataract; if nystagmus has developed, the amblyopia is irreversible. A treatment regimen based on surgery within 2 months of birth combined with prompt optical correction of the aphakia and aggressive occlusion therapy with frequent follow-up has been successful in unilateral and bilateral cases. Both anterior and posterior capsulorhexes are performed in most children. Intraocular lens implantation can be performed safely in children older than 1 year. Anterior dry vitrectomy is recommended in preschool children to avoid after-cataract. Opacification of the visual axis is the most common complication of cataract surgery in children. Secondary glaucoma is the most sight-threatening complication and is common if surgery is performed early. Life-long follow-up is essential in these cases.

Reduced bone mineral density and radial bone growth in young rabbits treated with dexamethasone eye drops

OBJECTIVE

To investigate the effect of dexamethasone eye drops on bone metabolism in newborn rabbits.

METHODS

Thirty-four 3-week-old rabbits had unilateral clear lens extraction and were randomized into three groups. Postoperatively, group 1 received high-dose and group 2 low-dose dexamethasone eye drops (average doses 0.27 and 0.10 mg/kg body weight/day, respectively). These rabbits also received a postoperative subconjunctival injection of betamethasone. Group 3 (control) received vehicle eye drops only. After 8 weeks of treatment, all animals were killed and the left femurs were isolated and subjected to peripheral quantitative computerized tomography (pQCT) and dual X-ray absorptiometry (DXA) analyses.

RESULTS

DXA showed that rabbits treated with either a high or low dose of dexamethasone eye drops had significantly reduced areal bone mineral density (BMD), area and total bone mineral content (BMC) of the femur. Measurements with pQCT demonstrated a dose-dependent reduction in cortical BMC, cortical volumetric BMD and cortical area. These effects were associated with an inhibition of radial femur growth, cortical thickness and periosteal and endosteal circumferences.

CONCLUSION

Dexamethasone eye drops have systemic effects affecting several bone parameters in young rabbits. Any long-term systemic effects of ocular glucocorticoids need to be further studied.

Single-piece AcrySof in the newborn rabbit eye

PURPOSE

To evaluate the behavior of the single-piece AcrySof SA30AT intraocular lens (IOL) (Alcon) in the eyes of newborn rabbits and to compare the postoperative complications in aphakic and pseudophakic eyes.

SETTING

St. Erik's Eye Hospital, Stockholm, Sweden.

METHODS

Clear lens extraction was performed in both eyes of 20 3-week-old rabbits. In 1 randomly selected eye in each rabbit, a single-piece acrylic IOL was implanted. Preoperatively and 1 and 2 months postoperatively, axial length and corneal diameter were measured. Corneal thickness was measured at the endpoint. The rabbits were also examined clinically; the position of the IOL and signs of secondary glaucoma were noted. At 2 months, the 19 surviving animals were killed. In 10 rabbits, the wet mass of the after-cataract was measured, and the eyes of 9 rabbits were fixed in formalin for histologic evaluation.

RESULTS

One animal died soon after surgery. Three rabbits developed secondary glaucoma in the aphakic eye. No rabbit developed glaucoma in the pseudophakic eye. In the 16 animals without secondary glaucoma, there were no significant differences in corneal diameter at 1 and 2 months or in corneal thickness at the endpoint; the axial length was significantly longer in aphakic eyes at 1 month, but not at 2 months. The aphakic eyes developed more posterior synechias and the pupil size at 1 and 2 months was significantly smaller in aphakic eyes than in pseudophakic eyes. Significantly more after-cataract developed in aphakic eyes than pseudophakic eyes (eyes with secondary glaucoma included). No difference in inflammation was seen between eyes in the histologic evaluation. In 11 of 19 pseudophakic eyes, the anterior capsulorhexis was not completely on the optic. In these eyes, the optic moved partly forward into the anterior chamber.

CONCLUSION

The single-piece AcrySof SA30AT IOL seems to induce less inflammation and probably inhibits secondary glaucoma. It does not retard eye growth as much as previously tested IOLs. However, it is important to keep the entire capsulorhexis margin on the optic, especially in these small eyes.

Outcome after treatment of congenital unilateral cataract

PURPOSE

To evaluate long-term functional outcome after treatment of congenital unilateral cataract.

METHODS

The records of 30 consecutive children operated on before the age of 12 months at St. Erik's Eye Hospital over a 5-year period (1991-96) were reviewed retrospectively. The patients were followed until 4-9.5 years of age. Linear Snellen visual acuity (VA), occlusion therapy compliance, and the presence of nystagmus, strabismus and other complications are reported.

RESULTS

Six children achieved VA of 0.1 or better. They were all operated on before 3 months of age. Of the 12 infants operated on before 6 weeks of age, four have VA between 0.3 and 0.4 and eight have VA of finger counting or less. Four developed severe secondary glaucoma within 6 months of cataract extraction. Two of these had persistent fetal vasculature. Three eyes developing glaucoma became amaurotic. Occlusion therapy was abandoned before the age of 2.5 years in 21 children.

CONCLUSION

Good levels of VA were achieved only in children who underwent cataract surgery before 3 months of age and who adhered to the occlusion therapy schedule. Severe secondary glaucoma developed in four out of 12 children operated on within 6 weeks. Full compliance with the occlusion therapy programme was uncommon.