Visual acuity of eyes after vitrectomy for ROP.
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Biomedical subjects
Publications and source records attributed to S R Lambert.
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PURPOSE: The authors report the clinicopathologic features of a recurrent retinoblastoma after radioactive iodine 125 (125l) plaque therapy. METHODS: The clinical and histopathologic findings of a 1-year-old boy with a recurrent retinoblastoma after 125l radioactive plaque application were reviewed. The patient's enucleated right eye was processed for routine histologic evaluation. Immunostains for glial fibrillary acid protein and S-100 protein were performed. RESULTS: Examination of the enucleated eye revealed a retinal tumor composed of two populations of cells. One population consisted of poorly differentiated cells, and the second population at the base of the tumor contained well-differentiated cells with numerous fleurettes. Immunohistochemical stains were positive for glial fibrillary acid protein and S-100 protein in the well-differentiated portion of the tumor. CONCLUSION: This case illustrates a recurrent retinoblastoma that may have arisen from radioresistant well-differentiated cells after 125l plaque therapy.
PURPOSE: To evaluate the affect of removing the crystalline lens and implanting an intraocular lens on the axial elongation of a neonatal eye. METHODS: Monocular lensectomy coupled with the implantation of a monofocal or multifocal intraocular lens was performed on 21 neonatal rhesus monkeys. Fellow eyes were randomized to part-time occlusion therapy or no treatment. Longitudinal axial elongation of the pseudophakic eyes was then compared to that of the fellow eyes, to the eyes of 19 monkeys made monocularly aphakic as neonates, and to the eyes of 39 normal monkeys. RESULTS: At 5 weeks of age, aphakic and pseudophakic eyes were significantly shorter than their fellow eyes (P < 0.01). After 1 year of follow-up, the mean axial lengths of the pseudophakic and aphakic eyes were 2.0 +/- 0.2 mm and 2.3 +/- 0.2 mm, respectively, shorter than their fellow eyes. This axial length difference persisted through a second year of follow-up. The difference between the mean axial lengths of the aphakic and pseudophakic eyes was not significant (P > 0.10). Part-time occlusion of the fellow eyes did not affect axial elongation. CONCLUSIONS: Removing the crystalline lens and implanting an intraocular lens in a neonatal monkey eye retards its axial elongation.
PURPOSE: The authors used a monkey model to evaluate intraocular lenses (IOLs) for the treatment of infantile cataract in humans. Specifically, they sought to assess the effectiveness of IOLs, with and without occlusion therapy, in preventing amblyopia. METHODS: A diffuser contact lens was placed on one eye each of 11 neonatal monkeys to simulate an infantile cataract. A unilateral lensectomy, combined with the implantation of an IOL, was performed on the same eye 1 to 2 weeks after birth. Clear contact lenses were used to adjust the optical correction of the pseudophakic eyes to a near point, and opaque lenses were used to maintain daily part-time (70%) occlusion of the fellow eyes of half the subjects. Behavioral methods were used to assess grating acuity, optotype acuity (Landolt C), and contrast sensitivity. RESULTS: In five of the animals, complications that developed in the eye with the implant were severe enough to interfere with visual function. The authors present only behavioral outcomes obtained before or in the absence of surgical complications. In monkeys that underwent daily 70% occlusion, grating acuity in the pseudophakic eyes eventually matured to normal adult levels. Grating acuity was significantly poorer in animals with no occlusion therapy. Even in animals with normal grating acuity, assessments of optotype acuity revealed amblyopic deficits; contrast sensitivity was impaired as well at middle and low spatial frequencies. CONCLUSIONS: The current study demonstrates that if there are no complications secondary to surgery, normal grating acuity can be obtained in neonatal monkey eyes that undergo IOL implantation, optical correction of the pseudophakic eye to a near point, and 70% occlusion of the fellow eye. However, these good outcomes for grating acuity cannot be attained without occlusion therapy. In addition, optotype acuity and sensitivity to contrast always are impaired.
BACKGROUND: Infants with stage 5 retinopathy of prematurity (ROP) usually experience severe visual loss, even when the retina is reattached surgically. Such visual loss has been attributed to persistent retinal dysfunction in most cases, but this has not been established electroretinographically. METHODS: Electroretinograms (ERGs) were performed on 5 eyes of 4 children with partial or complete retinal attachment after vitreoretinal surgery for stage 5 ROP. Duration of detachment before surgery was 2 weeks in 1 eye, 4-5.5 weeks in 3 eyes, and 15 weeks in 1 eye. The ERG findings for these eyes were then compared with ERG findings in a child with regressed ROP after laser photoablation of the peripheral avascular retina. RESULTS: All of the eyes with surgically repaired stage 5 ROP had nonrecordable ERGs. The child with regressed ROP after laser photoablation had an attenuated but recordable ERG. CONCLUSION: Severe retinal dysfunction persists in eyes with stage 5 ROP even after the retina is surgically reattached, which is probably one of the primary reasons that these eyes continue to have a poor visual outcome.
PURPOSE: To compare the effects of a lensectomy with and without intraocular lens (IOL) implantation on a neonatal rhesus monkey eye. METHODS: A lensectomy and anterior vitrectomy was performed on 75 monkeys during the first 16 days of life; 21 of these monkeys also had an IOL implanted into the posterior chamber. The eyes were examined at regular intervals using biomicroscopy, applanation tonometry, and ophthalmoscopy. RESULTS: The pseudophakic monkeys were studied until they were 92.5 +/- 5.8 weeks of age and the aphakic monkeys until they were 80.4 +/- 5.7 weeks of age. Pupillary membranes (100% versus 55.5%; P < 0.01) and lens regeneration into the pupillary aperture (28.6% versus 5.6%; P = 0.02) occurred more often in the pseudophakic than the aphakic eyes. As a result, the pseudophakic eyes required more reoperations than the aphakic eyes to keep the visual axis clear (P < 0.01). There was not a significant difference in the incidence of ocular hypertension between the pseudophakic and aphakic eyes (9.5% versus 12.7%; P = 0.34). Pupillary capture of the IOL optic occurred in 52% and haptic breakage in 33% of the pseudophakic eyes. All of the eyes with broken haptics had a prominent Soemmerring's ring varying in maximum thickness from 0.6 to 2 mm. Nine of the haptics from the seven eyes with broken IOLs had eroded into the iris, two into the ciliary body, and one into the anterior chamber. CONCLUSIONS: Implanting an IOL into a neonatal monkey eye after a lensectomy and anterior vitrectomy increases the likelihood of a reoperation being necessary. Haptics frequently erode into the iris and ciliary body and may break because of stress placed on the optic-haptic junction by forward movement of the IOL.
BACKGROUND: Patients at risk for retinol deficiency in developed countries include those with hepatic dysfunction and malabsorption states. Symptoms of retinol deficiency may go unrecognized or unreported. METHODS: The authors describe 15 patients with hepatic dysfunction, two of whom had procedures that would predispose to malabsorption and were ophthalmologically symptomatic of retinol depletion. The other 13 patients were ophthalmologically asymptomatic liver transplant candidates examined prospectively for subclinical evidence of retinol deficiency. Combined laboratory analysis, Schirmer's testing, conjunctival impression cytology, and electroretinography were performed. RESULTS: Twelve of 15 patients had serum retinol levels below the lower limit of normal. Aqueous tear production was reduced in 7 of 14 patients. Abnormal conjunctival morphology was noted in 6 of 12 patients. Electroretinograms were abnormal in the two patients who were visually symptomatic and in seven of nine patients who were ophthalmologically asymptomatic. CONCLUSION: Subclinical, physiologically significant retinol deficiency may be a frequent and unrecognized problem among patients with hepatic dysfunction.
Pedigrees were obtained on 43 patients with confirmed Leber congenital amaurosis, a rare form of blindness caused by congenital dysfunction of the retina. All of the pedigrees were consistent with autosomal recessive inheritance and the segregation frequency using classical segregation analysis was 0.24 +/- 0.07. Six of the 7 affected sib pairs were concordant in regards to systemic abnormalities. Despite previous reports that Leber congenital amaurosis can be inherited either as an autosomal dominant or recessive condition, our findings support only an autosomal recessive inheritance of this disorder.
Two children with congenital stationary night blindness were originally diagnosed as having spasmus nutans. Both children had the typical features of spasmus nutans including asymmetric nystagmus, head shaking, and torticollis. The diagnosis of congenital stationary night blindness was established only after each child underwent electroretinography. The nystagmus associated with retinal disease can mimic many of the features of spasmus nutans. Children suspected of having spasmus nutans should undergo complete ophthalmologic examination and electroretinography if they are myopic.
Four patients with an ipsilateral hypertropia after cataract extraction consistent with superior rectus muscle overaction were identified between March 1990 and April 1992. Operative trauma was the most likely causative factor, as other likely conditions were excluded. The proposed pathogenesis for all cases is similar to that of botulinum type-A toxin therapy: a transient postoperative weakness of the ipsilateral inferior rectur muscle leads to a contracture or strengthening of the ipsilateral antagonist (the superior rectus muscle). Possible mechanisms of injury that would result in a transient inferior rectus muscle palsy would include anesthetic myotoxicity or direct trauma to the muscle and related structures from the retrobulbar injection (or subconjunctival injection). Surgical intervention consisting of an ipsilateral superior rectus muscle recession and posterior fixation sutures (when the vertical incomitance was large) yielded excellent results in restoring single binocular vision. Possible preventive measures would include using a minimal volume of anesthetic along with careful needle placement.
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We treated one patient with bilateral internuclear ophthalmoplegia and another with skew deviation with extraocular muscle botulinum toxin injection. Both patients had pre-injection symptomatic diplopia in primary position, one for 1 month and the other for 12 months. Resolution of diplopia and complete and permanent binocular fusion in primary position was obtained within 3 to 4 days in both cases.
Isolated congenital hemianopias are typically caused by developmental abnormalities of the occipital lobe cortex. We describe two patients with an incidental partial hemianopia associated with unilateral periventricular leukomalacia that was acquired prenatally. Magnetic resonance imaging scans suggest a late second or early third trimester unilateral cerebral ischemic event.
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A 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. Joubert's syndrome should be suspected in children in whom dysgenesis of the cerebellar vermis and hypoplasia of the brainstem is shown on CT or MRI.
The authors report two children with isolated occipital lobe anomalies detected by visual evoked potentials (VEPs) and confirmed by MRI and CT scanning. Both had a markedly asymmetrical occipital distribution of flash and pattern VEPs. One child had acuity reduced to 6/36, and testing on confrontation suggested an homonymous hemianopia. The second child was visually inattentive to one side during infancy. Neither child had band atrophy of the optic disc or an afferent pupillary defect. Isolated abnormalities of the occipital lobes are difficult to detect by clinical examination during infancy and early childhood. Recording VEPs from a horizontal array of occipital electrodes can be helpful in detecting subtle occipital lobe abnormalities.
We reexamined 75 children in whom Leber's congenital amaurosis had been previously diagnosed. On review, 30 of these patients had an ocular or systemic disorder other than Leber's congenital amaurosis. The most common of these revised diagnoses were congenital stationary night blindness, achromatopsia, infantile-onset retinitis pigmentosa, Joubert's syndrome, Zellweger syndrome, and infantile Refsum's disease. Of the 45 patients with Leber's congenital amaurosis, mental retardation occurred in six patients, and visual deterioration in six patients. Leber's congenital amaurosis should only be diagnosed if other known ocular and systemic disorders have been carefully excluded.
Three children developed the congenital varicella syndrome following a maternal varicella infection during the second trimester of pregnancy. Systemic findings included a bulbar palsy, mild hemiparesis, cicatricial skin lesions, developmental delay, and learning difficulties. Ocular findings included chorioretinitis, atrophy and hypoplasia of the optic discs, a congenital cataract, and Horner's syndrome. Electroretinograms and pattern-reversal visual-evoked potentials recorded from the four eyes with chorioretinitis were attenuated and degraded. Two of the children had been misdiagnosed as having congenital toxoplasmosis. Chorioretinal scars probably occur more frequently with the congenital varicella syndrome than has been previously recognized and should be included in the differential diagnosis of congenital chorioretinal scars. Hypoplasia of the optic disc may develop after an intrauterine varicella infection during the 16th week of gestation. Children with the congenital varicella syndrome should be examined by an ophthalmologist to exclude ocular abnormalities. These abnormalities are often subtle and difficult to diagnose correctly.