Keith S. Morgan

Treatment of congenital glaucoma.

We reviewed 37 consecutive patients who had undergone at least one goniotomy, filtering surgery, and patching for amblyopia because of congenital glaucoma between 1969 and 1979. Of 32 eyes treated for uncomplicated congenital glaucoma, 25 (78%) achieved satisfactory control of intraocular pressure. Seven of the 12 eyes (58%) for which Snellen visual acuities could be obtained had visual acuities of 6/15 (20/50) or better. Of eight eyes treated for complicated congenital glaucoma, four (50%) achieved satisfactory control of intraocular pressure, but the visual acuities of these patients could not be tested.

Secondary Cataracts in Infants After Lensectomies

Three infants, one who was two weeks old, and two who were two months old, underwent lensectomy and vitrectomy in a total of four eyes for congenital cataracts by means of an automated suction cutter. Two patients with unilateral opacities underwent combined cataract extraction and epikeratophakia, and one with bilateral congenital cataracts underwent cataract extractions and was fit with extended wear contact lenses. In all cases, the surgery involved at least a 5-mm posterior capsulotomy with a shallow anterior vitrectomy, and was uneventful. Three of the four eyes developed new opacities that required surgical removal three to five months after the original surgery. Cytological evaluation of the specimen obtained from one patient showed this material to be lens epithelium. In all three cases, the material grew without the support of the posterior capsule; in one patient the material appeared to have seeded onto the iris. This previously unreported complication in infants with congenital cataracts who have undergone posterior capsulotomy and anterior vitrectomy emphasizes the need for frequent retinoscopies on such patients. The absence of the posterior capsule does not guarantee that these children will not develop secondary growth of lens epithelium which may obstruct the visual axis.

The use of epikeratophakia grafts in pediatric monocular aphakia.

Epikeratophakia is a form of refractive surgery in which the recipients epithelium is removed and a pre-shaped donor lenticule is sutured to the patients cornea. Seventeen patients ranging in age from two months to 6.6 years received 19 epikeratophakia grafts for the correction of aphakic vision. The correction provided by the graft in combination with vigorous amblyopia therapy has yielded some improvement in vision in the 12 patients with successful grafts. This procedure may be particularly suitable for pediatric aphakic patients because it is extraocular and reversible and may be employed as a secondary procedure or in conjunction with cataract extraction. Only with longer follow-up of these and additional patients can these preliminary results be validated and the risk/benefit ratio of this procedure be assessed.

Oral Fluorescein Angioscopy in Aphakic Children

Seven children who had undergone removal of congenital cataracts were evaluated postoperatively for cystoid macular edema during outpatient visits. Fluorescein was administered orally in a fruit juice cocktail, and the eyes examined by angioscopy 10-20 minutes and 45-60 minutes after dye ingestion. No evidence of macular leakage was observed in any of the 11 eyes examined. It appears that this diagnostic procedure is feasible in young patients, and that the incidence of cystoid macular edema after congenital cataract extraction may be less than has been previously reported.

The Nationwide Study of Epikeratophakia for Aphakia in Older Children

A nationwide study of epikeratophakia for aphakia in older children was conducted from March 1984 to March 1986. Sixty-three patients, 8 to 18 years of age, underwent this procedure in 65 eyes. Twenty-eight patients had congenital cataracts and 35 had traumatic cataracts. Fifty-one of the 65 eyes were aphakic at the time of surgery (secondary procedures). All surgeries were successful; no tissue lenses were lost or removed. Postoperatively, 73% of the patients were within 3 diopters (D) of emmetropia. The patients with congenital cataracts gained an average of one Snellen line of best-corrected visual acuity; patients with traumatic cataracts lost an average of one Snellen line of best-corrected visual acuity. In older pediatric patients, epikeratophakia appears to be a safe and effective procedure for the correction of aphakia.

Epikeratophakia in children with traumatic cataracts.

Epikeratophakia provides a permanent optical correction for aphakia in children with congenital or traumatic cataracts; suturing the epikeratophakia graft onto the cornea eliminates the problems of contact lens or spectacle non-compliance in these young and generally uncooperative patients and provides tectonic support to scarred and irregular corneas. Eighteen children under the age of six years underwent epikeratophakia for the correction of aphakia after the removal of trauma-induced cataracts. Graft success rate was 88%; the average change in keratometry in the patients with successful grafts was 14.82 +/- 2.0 diopters. In the 13 patients eligible for visual acuity tabulation, preoperative acuities ranged from light perception to 20/200, and postoperative acuities ranged from hand motions to 20/30. Ten (77%) had acuities of 20/80 or better. Poor results in three patients with less than 20/200 acuities were likely the results of non-compliance with amblyopia therapy. Present work indicates that in cases of traumatic cataract, the epikeratophakia procedure facilitates amblyopia therapy and decreases the astigmatism in scarred and irregular corneas.

Epikeratophakia in children with corneal lacerations

Epikeratophakia grafts were used to optically correct aphakia in six children who suffered traumatic cataracts and corneal lacerations which were greater than 3 mm in length. The ages of the patients at the time of corneal laceration ranged from nine months to 3 3/12 years. Five of the six grafts were successful. The average increase in corneal curvature was 16.11 diopters with an average over-refraction of -0.73 diopters. The deprivation interval in the five children with successful grafts ranged from two months to two years, and the average visual acuity for the four verbal patients with successful grafts was 20/60. This series demonstrates that epikeratophakia grafts can be successfully applied to scarred and irregular corneas and may be superior to penetrating keratoplasty in some cases, because epikeratophakia allows for a prompt restoration of visual function.

Prediction of Aphakic Refractive Error in Children

Formulas created to predict the optical requirements of the aphakic eye have been tested mainly in adult eyes. The accuracy of these formulas in shorter pediatric aphakic eyes was examined using retrospective analysis of 17 aphakic pediatric patients. The Sanders-Retzlaff-Kraff contact lens formula, used previously to predict required lens powers for epikeratophakia, consistently underestimated the required aphakic correction in the shorter eyes, which may have been responsible in part for the large undercorrections obtained previously in patients under one year of age. The Hoffer-Colenbrander and Binkhorst theoretical formulas, Donzis-Kastl-Gordon percentage change formula, and a linear regression formula derived from the present data (LIN), were significantly more accurate. The differences between these formulas were not significant. The use of one of these formulas should facilitate prediction of required epikeratophakia lenticule power or intraocular lens power in young children.

Toxicity and Tolerance of 9-(2-Hydroxyethoxymethyl)Guanine

Acyclovir [9-(2-hydroxyethoxymethyl)guanine] is a new antiviral agent which has specific activity in virus-infected cells. The drug has a high therapeutic index in animal and laboratory models but had not been tested for toxicity in human eyes at the time of this study. A randomized double-blind study on patients requiring antiviral therapy for treatment or prophylaxis of herpetic ocular infections revealed minimal irritation associated with topical administration. Further controlled studies will be necessary to evaluate this compounds clinical efficacy.

The Acuity Card Procedure: Longitudinal Assessments

Traditional methods of visual assessment in preverbal pediatric patients rely on refined but subjective measurement techniques. A standard ophthalmologic examination includes evaluation of a childs fixation patterns, with performance ranked on the basis of ability to fix and follow an object (F & F) or maintain central, steady fixation (CSM). In the hands of a skilled clinician, these evaluations are important for diagnosis and treatment. Documentation of quantitative changes in visual abilities of preverbal patients, however, has only recently become feasible. We began using the acuity card procedure in our pediatric clinical practice more than 3 years ago. This assessment, a modified version of the standard Forced-Choice Preferential Looking paradigm (FPL), provides quantitative evaluation of visual functioning in preverbal patients. The total number of patients assessed on one or more occasions exceeds 900. Of this group, we followed 83 patients with at least four acuity card evaluations on separate visits. Thirty of these patients, all with different diseases, have been evaluated with acuity cards on six or more visits. We found the information provided by the acuity card assessments extremely helpful in quantifying the developmental and therapeutic changes in vision, previously monitored only qualitatively.