J. Allen Gammon

Penetrating Keratoplasty in Children

Retrospectively studied were 91 patients, 14 years of age or less, who had 152 penetrating keratoplasties in 107 eyes, with an average follow-up of 30.1 months. Survival analysis showed the probability of obtaining a clear graft at one year to be 60 +/- 8% in 45 eyes with congenital opacities, 70 +/- 8% in 31 eyes with opacities from trauma and 73 +/- 8% in 31 eyes with acquired nontraumatic opacities. Most failures occurred during the first postoperative year and were characterized by the gradual loss of graft clarity from undetermined cause. Twenty-nine percent (10) of the 34 eyes with congenital corneal opacities in which vision could be measured had a most recent visual acuity better than 6/120 (20/400). Irreversible amblyopia, glaucoma, other structural abnormalities of the anterior segment and mental retardation complicated visual rehabilitation in the congenital group. In the post-traumatic group, vision was better than 6/120 (20/400) in 45% (13) of 29 eyes, being limited by vitreoretinal pathology, fibrous ingrowth, and optic nerve damage from glaucoma. Visual acuity in the acquired, nontraumatic group was better than 6/120 (20/400) in 67% (20) of 30 eyes. The percentage of patients achieving 6/12 (20/40) or better in the congenital, post-traumatic, and nontraumatic groups were 3% (1/34), 17% (5/29), and 47% (14/30), respectively. In the congenital group, only patients with posterior polymorphous dystrophy obtained a visual acuity of 6/30 (20/100) or better. Preoperative vascularization of the cornea, persistent epithelial defects, and performance of lensectomy-vitrectomy were factors most highly correlated with poor graft survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Ptosis Associated with Botulinum Toxin Treatment of Strabismus and Blepharospasm

The incidence, severity, and duration of ptosis after botulinum neurotoxin type A (BAT) injections into extraocular or orbicularis muscles were reviewed retrospectively. Even though lid droop frequently complicated botulinum toxin treatment in this series, no loss of vision or permanent ptosis was encountered. Sixty-seven injections were completed in 44 patients between September 1982 and December 1983. The records were reviewed to determine the incidence of ptosis after these 67 injections. Information was not adequate to ascertain the presence or absence of ptosis after 10 injections. Some degree of ptosis developed after 30 (53%) of the 57 injections with adequate follow-up history. Marked ptosis occurred after 12 (21%) of the 57 injections. The posttreatment lid droop in these 12 cases was potentially visually significant. All cases of ptosis, which impinged on the visual axis, resolved to a level permitting undisturbed vision by eight weeks after toxin injection. The incidence of ptosis was similar in patients who received injections into their medial rectus muscles and in patients who received injections into their lateral rectus muscles. However, an increased incidence of marked ptosis may be associated with the injection of previously operated muscles. Toxin dosage, patient age, and quality of the electromyogram used to monitor the injection showed no statistically significant relationship to the ptosis.

Management of extended-wear contact lenses in infant rhesus monkeys

Infant rhesus monkeys were fitted with extended-wear contact lenses (EWCLs) to correct surgically induced aphakia. The protocol that produced the most favorable experimental outcome, including good lens-wear compliance, involved: (1) custom-made EWCLs with parameters adjusted for each animal, (2) selection for study of neonates who seemed to tolerate EWCLs most naturally, (3) individual housing of monkeys, (4) lens check at 2-h intervals around the clock by trained personnel, (5) a large inventory of EWCLs for each animal, (6) periodic ophthalmologic examinations, and (7) darkroom housing of monkeys during treatment of lens-wear-related incidents. The EWCL is a new tool for studies of the visual system and is a useful complement to existing experimental techniques.

The Correction of Aphakia in Infants with Hydrogel Extended-wear Contact Lenses Corneal Studies

Although hydrogel extended-wear contact lenses (EWCLs) have been used extensively in the correction of aphakia in neonates, little is known about the effects of these lenses on infant corneas. Recent studies have demonstrated that long-term contact lenses can induce endothelial morphometric changes, including an increased coefficient of variation (CV) of mean endothelial cell area. Using wide-field specular microscopy, the authors studied 11 eyes of 10 patients, 1 to 3 years of age who, after lensectomy for congenital cataracts, wore EWCLs for the correction of aphakia. Except for two corneas in which increased pachometric readings and CV developed after repeated episodes of lens loss and inflammation, the EWCL were well tolerated and associated with few complications in this study.

Extended-wear Contact Lens Correction of Aphakia in Infant Primates: Corneal Studies

Extended-wear contact lenses (EWCL) are being used increasingly for the correction of aphakia in infants, but there is a lack of data documenting their effects on the corneas of young children. Therefore, corneal studies were performed on infant monkeys wearing EWCL for the correction of surgical aphakia. Nine newborn monkeys underwent unilateral lensectomy and anterior vitrectomy. Seven eyes were fitted with aphakic EWCL postoperatively and two wore no lenses. After at least six months, corneas were studied with slit-lamp and specular microscopy, and with light microscopy (LM) and electron microscopy (EM). Small central corneal opacities developed in two aphakic eyes corrected with EWCL after episodes of keratoconjunctivitis. One of these corneas was found to have a mildly increased coefficient of variation (CV) of endothelial cell size (polymegathism). Although EWCL are well tolerated by the corneas of aphakic infant primates, their association with endothelial polymegathism, which may indicate physiologic compromise, mandates careful long-term follow-up.

Visual evoked potential pattern generation, recording, and data analysis with a single microcomputer

A single microcomputer is used to generate multiple sets of checkerboard patterns, simultaneously record EEG data for visual evoked potentials, and analyze the results by fast Fourier transform in very rapid sequence under operator control. This system permits efficient estimates of visual acuity in infants with ophthalmological and neuro-ophthalmological disease.