Long-Term Visual Acuity Unaffected by Intraocular Lens Implantation After Congenital-Cataract Surgery

By Will Boggs MD

March 05, 2020

NEW YORK (Reuters Health) - Intraocular lens (IOL) implantation at the time of surgery for congenital cataract during infancy neither improves nor worsens long-term visual acuity, compared with correction with contact lenses, according to findings from the Infant Aphakia Treatment Study (IATS).

"When we started the study, our hypothesis was that children who underwent intraocular lens implantation would have better visual outcomes than children who were left aphakic and treated with contact lenses," Dr. Scott R. Lambert of Stanford University School of Medicine, in Palo Alto, California, told Reuters Health by email. "This proved not to be the case."

IATS previously reported that visual outcomes at age 12 months and 4.5 years were similar for children randomized to receive an IOL at the time of cataract extraction compared with those who did not.

Dr. Lambert and colleagues from 12 clinical sites now extend these results by comparing visual-acuity outcomes in patients at age 10.5 years using the Early Treatment of Diabetic Retinopathy Study testing protocol after the sensitive period for visual development had been completed.

This follow-up study included 55 children in the IOL group and 55 children in the aphakia group. Among the 55 children randomized to the aphakia group, 24 later received an IOL implant, 18 continued to wear a contact lens, nine wore only eyeglasses and four were wearing no optical-correction device.

Overall, the best-corrected visual acuity for the treated eyes varied considerably (from logMAR 0.00 to 2.93). The median visual acuity did not differ significantly between children randomized to aphakia (0.86; Snellen equivalent, 20/145) and those randomized to receive an IOL (0.89; Snellen equivalent, 20/159).

In the aphakia group, the median logMAR acuity was best for children who continued to wear a contact lens (0.37; Snellen equivalent, 20/47), followed by those who underwent secondary IOL implantation (0.92; Snellen equivalent, 20/166), those who wore eyeglasses (1.46; Snellen equivalent, 20/577), and those who had no correction (1.60; Snellen equivalent, 20/796).

Median logMAR binocular vision was similar for the two treatment groups, the researchers report in JAMA Ophthalmology.

"It is definitely worth the effort to treat children with unilateral congenital cataracts," Dr. Lambert said. "While it is true that 44% of these eyes had 20/200 or worse vision, 20% of them had excellent vision in these eyes."

"We are optimistic with earlier detection and the adoption of best practices that the number of children with excellent outcomes will increase," he said. "However, it is important to emphasize to parents that a great deal of effort will be required on their part to achieve a good visual outcome. Cataract surgery is only the first step in a long journey for these parents, with daily part-time patching and contact lenses and spectacles adherence critical to a good visual outcome."

"We are hoping that the results of this study can be leveraged to mandate that all insurance companies in the U.S. cover the cost of aphakic contact lenses for aphakic children," Dr. Lambert added. "Currently the cost of these lenses is frequently borne by parents. We view aphakic contact lenses to be a type of 'prosthesis,' since the lens has been removed in these eyes."

Dr. Michael X. Repka of the Johns Hopkins Wilmer Eye Institute, in Baltimore, Maryland, who wrote a linked commentary on the report, told Reuters Health by email, "The chance of future issues is high, as is the need for additional surgery. Unfortunately, this was a selected group with the best prognosis, so it does not generalize to bilateral cataracts or those with structural abnormalities beyond the cataract."

"It is a lot of work, but some patients will do fantastic, while others will do middling, and a few just won't do well," he said.

SOURCE: https://bit.ly/2wfvvQi and https://bit.ly/2waT5xM JAMA Ophthalmology, online February 20, 2020.