David R. Weakley

The association between nonstrabismic anisometropia, amblyopia, and subnormal binocularity.

PURPOSE To determine if thresholds exist for the development of amblyopia and subnormal binocularity with various types of anisometropia and to compare these with existing guidelines for the treatment or observation of anisometropia. DESIGN The records of all previously untreated patients evaluated for isolated refractive error during a 42-month period were reviewed to assess the association between anisometropia, amblyopia, and subnormal binocularity. PARTICIPANTS Three hundred sixty-one (361) patients with anisometropia and 50 nonanisometropic control participants, examined over a 42-month period, with no history of treatment for refractive error, amblyopia, or other ocular pathologic characteristics were evaluated. METHODS Uncorrected visual acuity in each eye, monofixation response, and degree of stereopsis were recorded for each patient. Patients with unequal or subnormal uncorrected visual acuity were retested with cycloplegic refraction. If the visual acuity was still abnormal, patients were retested while wearing spectacles. MAIN OUTCOME MEASURES Degree and type of anisometropia were compared with incidence and severity of amblyopia and subnormal binocularity. RESULTS Spherical myopic anisometropia (SMA) of more than 2 diopters (D) or spherical hypermetropic anisometropia (SHA) of more than 1 D results in a significant increase in the incidence of amblyopia and decrease in binocular function when compared with nonanisometropic patients (P = 0.05). Increasing levels of SMA and SHA beyond these thresholds result in increased incidence and severity of amblyopia. Cylindrical myopic anisometropia (CMA) or cylindrical hyperopic anisometropia (CHA) of more than 1.5 D results in a significant increase in amblyopia and a decrease in binocular function (P = 0.05). Levels of CMA and CHA more than 1.5 D result in an increased incidence and severity of amblyopia. CONCLUSIONS This study supports existing guidelines for the treatment or observation of anisometropia and characterizes the association between the type and degree of anisometropia and the incidence and severity of amblyopia and subnormal binocularity.

The Infant Aphakia Treatment Study: Design and Clinical Measures at Enrollment

OBJECTIVE To compare the use of contact lenses and intraocular lenses (IOLs) for the optical correction of unilateral aphakia during infancy. METHODS In a randomized, multicenter (12 sites) clinical trial, 114 infants with unilateral congenital cataracts were assigned to undergo cataract surgery with or without IOL implantation. Children randomized to IOL treatment had their residual refractive error corrected with spectacles. Children randomized to no IOL treatment had their aphakia treated with a contact lens. MAIN OUTCOME MEASURES Grating acuity at 12 months of age and HOTV visual acuity at 4 1/2 years of age. APPLICATION TO CLINICAL PRACTICE This study should determine whether either treatment for an infant with a visually significant unilateral congenital cataract results in a better visual outcome. RESULTS Enrollment began December 23, 2004, and was completed January 16, 2009. The median age at the time of cataract surgery was 1.8 months. Fifty patients were 4 to 6 weeks of age at the time of enrollment; 32, 7 weeks to 3 months of age; and the remaining 32, more than 3 to less than 7 months of age. Fifty-seven children were randomized to each treatment group. Eyes with cataracts had shorter axial lengths and steeper corneas on average than the fellow eyes. CONCLUSIONS The optimal optical treatment of aphakia in infants is unknown. However, the Infant Aphakia Treatment Study was designed to provide empirical evidence of whether optical treatment with an IOL or a contact lens after unilateral cataract surgery during infancy is associated with a better visual outcome.

Delayed consecutive exotropia following 7-millimeter bilateral medial rectus recession for congenital esotropia

The rate of delayed consecutive exotropia after bilateral 7-millimeter medial rectus recession for large angle congenital esotropia in 88 patients was 27% (24/88), larger than previously reported. The rate was 38% (8/21) in infants having surgery prior to 7 months of age, 20% (10/49) in infants undergoing surgery at 7 to 12 months of age, and 33% (6/18) in patients undergoing surgery at 13 months of age or later. The onset of consecutive exotropia averaged 26.8 months postoperatively, allowing a long period of good alignment for binocular vision to develop before exotropia surgery was required. Physicians and parents should be aware that delayed consecutive exotropia may develop several years postoperatively. Since delayed consecutive exotropia may be characteristic of the 7-millimeter recession procedure or characteristic of all patients who have had surgery for congenital esotropia, a prospective long-term study to compare the 7-millimeter procedure with the three- and four-muscle procedure would be helpful.

Office probing of congenital nasolacrimal duct obstruction.

We report the results of office nasolacrimal duct probing under topical anesthesia in 2369 eyes with symptomatic nasolacrimal duct obstruction. The overall success rate for cure by initial probing was 92%. In patients less than 9 months old, a 94% cure rate was achieved with one probing; in patients 9 months and older, the rate decreased to 84%. The decrease in success rate after 9 months was statistically significant (P less than .00001 by chi-square analysis). A majority of 180 parents of these patients surveyed said they were happy with the office procedure and preferred having the probing performed to resolve symptoms, even though they realized that the symptoms most probably would resolve by 1 year of age without it. We conclude that office probing for congenital nasolacrimal duct obstruction is a safe and effective method for treatment of symptomatic nasolacrimal duct obstruction, allowing the cost and risk of general anesthesia as well as the cost and inconvenience of prolonged medical management to be avoided.

Treatment of severe amblyopia with weekend atropine: Results from 2 randomized clinical trials

PURPOSE To determine the effectiveness of weekend atropine for severe amblyopia from strabismus, anisometropia, or both combined among children 3 to 12 years of age. METHODS We enrolled children into 2 prospective, randomized multicenter clinical trials of amblyopia therapy. Herein we report the results for severe amblyopia, 20/125 to 20/400. In Trial 1, 60 children 3 to 6 years of age (mean, 4.4 years) were randomized to weekend atropine plus a plano lens or weekend atropine plus full spectacle correction for the sound eye. In Trial 2, 40 children 7 to 12 years of age (mean, 9.3 years) were randomized to weekend atropine or 2 hours of daily patching. The visual acuity outcome was assessed at 18 weeks in Trial 1 and 17 weeks in Trial 2. RESULTS In Trial 1, visual acuity improved by an average of 4.5 lines in the atropine plus correction group (95% CI, 3.2-5.8 lines) and 5.1 lines in the atropine plus plano lens group (95% CI, 3.7-6.4 lines). In Trial 2, visual acuity improved by an average of 1.5 lines in the atropine group (95% CI, 0.5-2.5 lines) and 1.8 lines in the patching group (95% CI, 1.1-2.6 lines). CONCLUSIONS Weekend atropine can improve visual acuity in children 3 to 12 years of age with severe amblyopia. Improvement may be greater in younger children.

Endophthalmitis Following Pediatric Intraocular Surgery for Congenital Cataracts and Congenital Glaucoma

The incidence of endophthalmitis following pediatric anterior segment surgery is currently unknown. The paucity of reports of this entity has led some observers to recommend simultaneous bilateral surgery for congenital cataracts or glaucoma. In this study, we surveyed over 500 pediatric ophthalmologists and glaucoma specialists concerning their knowledge of, or involvement with, endophthalmitis following pediatric intraocular surgery. Seventeen cases of endophthalmitis were documented to occur out of 24,000 reported surgical cases. This results in an incidence estimate of 0.071%, or 7 cases per 10,000, which is similar to that recently reported following adult extracapsular cataract extraction. The presence of infection was diagnosed by the 3rd postoperative day in 82% of cases. An organism was documented by culture in 65% of cases. The organism was gram positive in all cases. Visual outcome was generally poor with 65% having no light perception. The presence of possible concurrent risk factors for postoperative endophthalmitis, including nasolacrimal duct obstruction and upper respiratory infection, was noted in 8 of the 17 cases.

Primary treatment of nasolacrimal duct obstruction with nasolacrimal duct intubation in children younger than 4 years of age.

PURPOSE To report the outcome of nasolacrimal duct intubation as the primary treatment of congenital nasolacrimal duct obstruction (NLDO) in children younger than 4 years of age. METHODS A total of 182 eyes of 139 children receiving intubation with planned tube retention for 2 to 5 months were enrolled in a prospective, nonrandomized observational multicenter study (19 sites). Children were ages 6 months to <45 months at the time of surgery, with no previous nasolacrimal surgical procedures and had at least one of the following clinical signs of NLDO: epiphora, mucous discharge, and/or increased tear lake. RESULTS Treatment success was defined as absence of epiphora, mucous discharge, and increased tear lake at the outcome visit, 1 month after tube removal. The surgical outcome was assessed in 150 eyes (82% of cohort). The proportion of eyes treated successfully was 91% (95% CI: 86%-95%). The outcome dye disappearance test was normal in 125 (86%) eyes, indeterminate in 13 (9%), and abnormal in 7 (5%) of the 145 eyes tested. Monocanalicular tubes were used in 74% of cases. The tube was removed before the planned minimum retention time of 2 months in 61 eyes (41%). For 23 eyes, the early removal was attributed to inadvertent displacement by the patient. CONCLUSIONS In children 6 months to <45 months of age, nasolacrimal duct intubation in a nonrandomized and noncomparative trial was a successful primary treatment of NLDO in about 90% of cases not lost to follow-up.

Long-Term Rates of PCO Following Small Incision Foldable Acrylic Intraocular Lens Implantation in Children

PURPOSE To evaluate the long-term incidence of postoperative posterior capsular opacification (PCO) in children undergoing small incision foldable acrylic lens implantation with at least 2 years of follow up. METHODS In 18 children, 26 eyes underwent small incision cataract extraction with posterior chamber foldable acrylic lens implantation. The posterior capsule was left intact in all patients at the time of surgery. RESULTS With a mean follow up of 2.75 years and a mean age at surgery of 8.25 years, 13 of 26 eyes (50%) developed visually significant PCO requiring intervention. In the group of children under 4 years of age, 5 of 5 eyes (100%) developed visually significant PCO, while 8 of 21 eyes (38%) in the group of children over 4 years of age developed opacification. Four of 26 eyes (15%) required two procedures (either repeat Nd:YAG laser capsulotomy or pars plana secondary membrane removal) to clear the visual axis. CONCLUSION In this study, the incidence of PCO following small incision acrylic lens implantation in children over 4 years of age is lower than those rates reported by conventional large incision rigid lens techniques with a minimum of 2 years follow up. This technique has advantages over conventional techniques in older children because it offers less surgical intervention, a lower cost to patients, and less risk of vitreous and retinal complications.

Pharmacological plus optical penalization treatment for amblyopia: Results of a randomized trial

OBJECTIVE To compare weekend atropine sulfate use augmented by a plano lens for the sound eye with weekend atropine use alone for moderate amblyopia in children aged 3 years to younger than 7 years. METHODS In a multicenter clinical trial, 180 children with moderate amblyopia (visual acuities of 20/40-20/100) were randomized to weekend atropine use augmented by a plano lens or weekend atropine use alone. MAIN OUTCOME MEASURE Masked assessment of amblyopic eye visual acuity using the Amblyopia Treatment Study HOTV testing protocol at 18 weeks. RESULTS At 18 weeks, amblyopic eye improvement averaged 2.8 lines in the group that received atropine plus a plano lens and 2.4 lines in the group that received atropine alone (mean difference between groups adjusted for baseline acuity, 0.3 line; 95% confidence interval, -0.2 to 0.8 line). Amblyopic eye visual acuity was 20/25 or better in 24 patients (29%) in the group that received atropine only and 35 patients (40%) in the group that received atropine plus a plano lens (P = .03). More patients in the group that received atropine plus a plano lens had reduced sound eye visual acuity at 18 weeks; however, there were no cases of persistent reverse amblyopia. CONCLUSIONS As an initial treatment for moderate amblyopia, the augmentation of weekend atropine use with a plano lens does not substantially improve amblyopic eye visual acuity when compared with weekend atropine use alone. Application to Clinical Practice Treatment of children with unilateral amblyopia. Trial Registration clinicaltrials.org Identifier: NCT00315302.

Seven-millimeter bilateral medial rectus recessions in infantile esotropia.

Thirty-six patients with large angle infantile esotropia averaging 74 prism diopters underwent 7-mm bilateral medial rectus recessions by the cul-de-sac approach. Successful horizontal alignment with the initial procedure when measured at the most recent follow-up examination (average 18.2 months postoperatively) was achieved in 27 patients (75%). Five patients (14%) were undercorrected and four patients (11%) were over-corrected. The advantages of the method, as opposed to three or four muscle procedures, are that it is quicker, simpler, and a less traumatic procedure which leaves the lateral rectus muscles unoperated for future surgeries if necessary. This is effective even in very large angle congenital esotropia.