Binocular function in pseudophakic children.

All pediatric ophthalmologists should be familiar with Dr. Malcom Ing’s classic work on binocularity and stereopsis in children following surgery for infantile esotropia. In this issue, Dr. Ing reports his results of visual and binocular testing performed on patients who had primary implantation of intraocular lenses following the removal of cataracts in their childhood. Monocular and binocular tests were performed on 21 patients who underwent surgery in the age range from 0.75 months to 11.1 years and who were observed for a minimum of 5 years by their surgeons. All but 2 patients had motor alignment within 8 prism diopters of orthotropia at near. Fusion and some stereopsis was found in 15 patients, but only 4 of these demonstrated fine (60 seconds of arc or better) stereoacuity. Patients with fine versus gross stereoacuity were compared and found to be similar in type of cataract, age at first surgery, interval between surgeries, length of follow-up, and refraction, but different in the quality of best-corrected visual acuity. The author concluded that, although satisfactory motor alignment, fusion, and some stereopsis is present in the majority of patients, fine stereoacuity as defined by 60 seconds of arc or better is uncommon in pseudophakic children. Why was fine stereoacuity an uncommon finding in patients who received an intraocular lens in childhood following cataract extraction? The author postulates that a slight disparity in the best-corrected visual acuity may be responsible. In general, there was not significant anisometropia in the patients studied, but it is possible that the optical corrections were too disparate, not given early enough, or not changed often enough during the clinical management in the past. Dr. Ing’s results should stimulate all pediatric ophthalmologists to study the binocularity and stereoacuity results in their own patients. It would seem that the age of development of a visually significant cataract and the interval between pseudophakic correction in the two eyes would be factors to carefully evaluate.