Fine stereoacuity found to be uncommon in pseudophakic children

This study reports the results of monocular and binocular tests performed on patients who had primary insertion of intraocular lenses following the removal of cataracts in their childhood. There have been no previous studies dedicated to the determination of motility and presence of fusion and stereopsis in pseudophakic children. The results of the current study indicate that although satisfactory motor alignment, fusion and some stereopsis are present in the majority of these patients, fine stereoacuity is uncommon in pseudophakic children.

The author says that these findings should be no real surprise, considering the many hurdles to developing monocular and binocular vision in children with cataracts and that it is generally recognized that excellent visual acuity is a prerequisite for fine stereoacuity. He concludes that the study's findings should serve to remind ophthalmic surgeons of the importance of achieving the maximum monocular visual acuity, whenever possible, as soon as possible, and not to neglect the role of follow-up refraction in helping patients achieve the highest quality binocular outcome.

The author performed monocular and binocular tests on 21 patients selected from consecutive series who had been followed for a minimum of five years by their surgeons. The subjects had undergone bilateral cataract extraction and bilateral IOL implantation by age 15 with one of four ocular surgeons.

The mean age at surgery performed on the first eye was 6.3 years. When the author's examination was conducted, mean age was 16.5 years and mean length of follow-up was 10.3 years. All but two patients had motor alignment within 8 prism diopters of orthotropia at near. Fusion and some stereopsis were found in 15 patients, but only four of them demonstrated fine (60 seconds of arc or better) stereoacuity. Type of cataract, age at first surgery, interval between surgeries, length of follow-up and refraction were similar when comparing patients with fine versus gross stereoacuity. However, monocular visual acuity scores in patients who demonstrated fine stereoacuity were superior to the visual acuity scores in those with worse binocularity. Monocular visual acuity was 20/30 or better in 26 of 34 eyes (76 percent) in patients who could be tested subjectively.

The majority of patients, if they maintained straight eyes, demonstrated a binocular result that was within the confines of a monofixation syndrome. If no previous manifest strabismus was present before cataract surgery was performed, satisfactory alignment was usually achieved, suggesting that some form of binocularity survived the onset and treatment of cataracts in both eyes. This occurred despite the fact that the onset of cataracts occurred at different times in some patients.