Scott R. Lambert

Optic nerve hypoplasia

Optic nerve hypoplasia is an easily overlooked, nonprogressive developmental anomaly which results in a wide range of visual deficits. It is frequently associated with clinically significant central nervous system and endocrine abnormalities. Maternal substance abuse is increasingly recognized in many cases. A supranormal regression of optic nerve axons in utero, rather than a primary failure of differentiation, is proposed as the pathogenesis.

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.

Pseudotumor cerebri in children

PURPOSE Demographic and outcome data in the era of modern neuroimaging are needed to describe pseudotumor cerebri in children. METHODS We reviewed the medical records of children less than 18 years old who were diagnosed with pseudotumor cerebri between 1977 and 1997. We defined pseudotumor cerebri as (1) increased intracranial pressure, (2) normal or small ventricles, and (3) normal cerebrospinal fluid composition. The condition might be idiopathic or the result of a nontumor etiology. RESULTS Thirty-seven patients had an initial diagnosis of pseudotumor cerebri. Two patients were subsequently diagnosed with a central nervous system malignancy and were excluded from further analysis. The remaining 35 patients included 10 patients with idiopathic pseudotumor cerebri and 25 patients with disorders reported to be associated with pseudotumor cerebri. The mean age was 10.6 years with a range of 3 to 17 years. Twenty patients (57%) were female and 13 patients (37%) were obese. At presentation 4 patients had a visual acuity less than 20/40 in the best eye and 10 patients had visual field deficits. Seventeen patients (49%) had cranial nerve deficits, all of which resolved with normalization of the intracranial pressure. Follow-up data were obtained on 30 patients. Only one patient had a final visual acuity less than 20/40 in the best eye, whereas six patients had residual visual field deficits. Ten patients (33%) had optic nerve atrophy. CONCLUSIONS There was no gender predominance, and associated etiologic factors were common in these children with pseudotumor cerebri. Permanent visual loss occurs in some children with pseudotumor cerebri. Quantitative perimetry and optic nerve examination were more sensitive than visual acuity determination in detecting damage to the visual sensory system. In rare instances the patient diagnosed with pseudotumor cerebri will be found after extended follow-up to harbor an intracranial neoplasm.

Joubert syndrome: a clinico-radiological study

SummaryA characteristic malformation of the cerebellum, including dysgenesis of the vermis and enlargement of the fourth ventricle was observed on computed tomography (CT) in 16 children on review of our consecutive material. Seven of these children underwent magnetic resonance imaging (MRI) which showed hypoplasia of the brainstem in addition to cerebellar vermian dysgenesis. One child had, in addition, dysgenesis of the corpus callosum. All these children were developmentally delayed, and many had neonatal breathing abnormalities, congenital retinal dystrophy and supranuclear ocular motor abnormalities. Jouberts syndrome should be suspected in children in whom dysgenesis of the cerebellar vermis and hypoplasia of the brainstem is shown on CT or MRI.

Unilateral intraocular lens implantation during the first six months of life

PURPOSE The purpose of this study was to determine the incidence of postoperative complications and the occurrence of myopic shift in infantile eyes after cataract surgery and implantation of an intraocular lens (IOL). METHODS Cataract surgery and IOL implantation was performed on 11 infants with unilateral congenital cataracts who had a mean age of 10+/-6 weeks at 5 clinical centers. IOLs with a mean power of 26.2+/-2.3 D were implanted using a standardized protocol. The infants were then followed up for a mean of 13+/-6 months for postoperative complications and longitudinal changes in their refractive error. RESULTS Eight of the 11 eyes had postoperative complications and were treated with a reoperation. Complications included open-angle glaucoma (n = 2), lens reproliferation into the visual axis (n = 2), pupillary membranes (n = 2), and corectopia (n = 2). A younger age at the time of surgery was positively correlated with the development of a postoperative complication requiring a reoperation (P = .03). A mean myopic shift of 5.49 D occurred in these eyes a year after surgery. No preoperative factors could be identified that correlated with the magnitude of the myopic shift. CONCLUSION IOL implantation during infancy is associated with a high complication rate frequently requiring reoperation. A large myopic shift typically occurs that necessitates an initial or a late overcorrection with spectacles or a contact lens, depending on the power of the IOL implanted. Until ongoing randomized trials are completed, we recommend that surgeons exercise caution before implanting IOLs in the eyes of infants.

A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes

OBJECTIVE To compare the rate of refractive growth in pseudophakic childrens eyes to that of aphakic eyes. DESIGN Multicenter, retrospective observational case series. PARTICIPANTS 83 patients with pseudophakic eyes (100 eyes) and 74 patients with aphakic eyes (106 eyes), with an age of surgery between 3 months and 10 years and a minimum follow-up time of 3 years or more, depending on the age at surgery. METHODS A logarithmic model was used to analyze the rate of refractive growth for each eye. MAIN OUTCOME MEASURES Age at surgery, intraocular lens power, intraocular lens A-constant, initial postoperative refraction, final refraction, and final age. RESULTS Overall, pseudophakic eyes showed a lesser rate of refractive growth than aphakic eyes (-4.6 diopter vs. -5.7 diopter, P = 0.03). This trend was also present but less significant when the eyes were grouped into those less than 6 months of age at surgery (-3.3 diopter vs. -4.6 diopter, P = 0.09) and older patients (-5.0 diopter vs. -6.1 diopter, P = 0.07). However, the mean quantity of myopic shift was greater in pseudophakic eyes than in aphakic eyes (-5.26 diopter vs. -4.54 diopter), despite shorter follow-up times in the pseudophakic eyes. This is due to the optical effects of a constant intraocular lens power in a growing eye. CONCLUSIONS Pediatric pseudophakic eyes have a slightly lesser rate of refractive growth than aphakic eyes. The new rate values should be used for predicting future refractions in these eyes.

Follow-up and Diagnostic Reappraisal of 75 Patients with Leber's Congenital Amaurosis

We reexamined 75 children in whom Lebers congenital amaurosis had been previously diagnosed. On review, 30 of these patients had an ocular or systemic disorder other than Lebers congenital amaurosis. The most common of these revised diagnoses were congenital stationary night blindness, achromatopsia, infantile-onset retinitis pigmentosa, Jouberts syndrome, Zellweger syndrome, and infantile Refsums disease. Of the 45 patients with Lebers congenital amaurosis, mental retardation occurred in six patients, and visual deterioration in six patients. Lebers congenital amaurosis should only be diagnosed if other known ocular and systemic disorders have been carefully excluded.

Effect of age at time of cataract surgery on subsequent axial length growth in infant eyes

PURPOSE To determine whether removal of the crystalline lens and placement of an intraocular lens (IOL) in human infant eyes retard the growth of the pseudophakic eye. METHODS A unilateral lensectomy with placement of a posterior chamber IOL in the sulcus was performed in 11 infants between 2 and 4 months of age. Axial length measurements of both eyes were obtained preoperatively and postoperatively. RESULTS Patients were followed for a mean of 5.6 years. In 7 patients, the mean axial growth was 0.46 mm less in the pseudophakic eye than in the fellow eye (range 0.15 to 0.70 mm). In 1 patient, there was no interocular axial length difference and in 3, the pseudophakic eye was longer. When measurements from the only patient with microphthalmia were excluded, the interocular difference in axial growth was highly significant (signed rank test, P = .006). Median visual acuity of the pseudophakic eyes at the last follow-up was 20/60 (range 20/30 to 20/200). The final visual acuity in the pseudophakic eyes did not correlate with the degree of interocular axial length difference (P > .05). CONCLUSIONS Our study suggests there may be a reduction in axial growth in infantile eyes following cataract extraction and IOL implantation. This effect probably reduces the magnitude of the myopic shift in these eyes.

Cataract and phthisis bulbi after laser photoablation for threshold retinopathy of prematurity

PURPOSE To describe the visual and structural outcome of eyes that developed a dense cataract after laser photoablation for threshold retinopathy of prematurity. METHODS A retrospective review of eight consecutive infants who developed dense cataract(s) after bilateral laser photoablation for threshold retinopathy of prematurity. Of the 10 eyes with cataract, five eyes were treated with a diode laser and five with an argon laser. The stage and zone of the retinopathy of prematurity, number of burns applied, time of onset of the cataract, clinical findings at the time of cataract surgery, and the course after cataract surgery were reviewed. RESULTS Six eyes had zone 1 disease and four had zone 2 disease. The mean number of burns applied per eye was 2532 +/- 856 (range, 1400 to 4500). A cataract was diagnosed a median of 3 [corrected] weeks (range, 1 to 28 weeks) after laser photoablation. Nine of the 10 cataracts were sufficiently dense to preclude a view of the fundus. All 10 eyes had clinical signs suggestive of an inflammatory or ischemic process that included one or more of the following findings: corneal edema, pupillary membrane, iris atrophy, depigmentation of ciliary processes, pigment on the anterior lens surface, posterior synechiae, hyphema, and shallow anterior chamber. Nine eyes underwent cataract surgery. Five of the 10 eyes had retinal detachment ranging in severity from stage 4A to stage 5 at the time of cataract surgery. Nine of the 10 eyes progressed to phthisis bulbi and no light perception. CONCLUSIONS A dense cataract developing in the eye of an infant after laser photoablation for threshold retinopathy of prematurity is associated with a poor visual prognosis. The constellation of associated clinical findings appears to be most consistent with anterior segment ischemia.

Long-term results of corneal graft survival in infants and children with peters anomaly.

OBJECTIVE To determine the long-term results of corneal graft survival after penetrating keratoplasty for Peters anomaly and to identify risk factors for graft failure. DESIGN Noncontrolled interventional case series: a single-center retrospective review of a consecutive surgical series. PARTICIPANTS The records of all children 12 years of age or younger who underwent penetrating keratoplasty for Peters anomaly between January 1971 and December 1992 were reviewed. All study eyes had completed a minimum of 3 years of follow-up from the date of first keratoplasty and had undergone most of their corneal surgery at Emory University. INTERVENTION Characteristics of the recipient, the eye, the donor, and the surgical procedure were analyzed for their influence on survival of the first graft. Survival probabilities were estimated using the Kaplan-Meier method. Multivariate regression analysis was performed to estimate relative risks and adjusted survival probabilities. MAIN OUTCOME MEASURE Graft clarity. RESULTS One hundred forty-four penetrating keratoplasties were performed in 72 eyes of 47 patients. The median age at first keratoplasty was 4.4 months. The median follow-up was 11.1 years. Fifty-four percent of eyes received one graft, 18% received two grafts, and 28% received three or more grafts. The overall probability of maintaining a clear first graft was 56% at 6 months, 49% at 12 months, 44% at 3 years, and 35% at 10 years. The probability of second or subsequent grafts surviving for 3 years was less than 10%. Thirty-nine percent of eyes had a clear graft at the time of review; 36% of eyes had a clear first graft. Multivariate analysis identified disease severity, donor cornea size, coexisting central nervous system abnormalities, and quadrants of anterior synechiae as the strongest risk factors for graft failure. Supplemental multivariate analysis, restricted to observable preoperative variables, identified stromal vessels, total limbal opacification, and preoperative glaucoma as independent preoperative predictors of graft failure. Allograft rejection was the most frequently identified cause of graft failure. Major complications after keratoplasty were phthisis, retinal detachment, cataract, and glaucoma. CONCLUSIONS The overall long-term probability of maintaining a clear graft after initial penetrating keratoplasty for Peters anomaly is 35% +/- 0.06%, with subsequent grafts rarely surviving. Eyes with severe disease, larger donor corneas, coexisting central nervous system abnormalities, and anterior synechiae have significantly poorer outcomes than eyes without these factors. These data should be carefully considered before recommending corneal transplantation for Peters anomaly, particularly after previous graft failure.