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Biomedical subjects

G L Rogers

Publications and source records attributed to G L Rogers.

At least 19 recordsLinked to original sources

Flash visual evoked response binocular summation in normal subjects and in patients with early-onset esotropia before and after surgery.

Flash visual evoked responses were recorded and visual evoked response binocular summation was assessed in normal children between the ages of 1 and 58 months, in normal adults and in children with early-onset esotropia before and longitudinally for 1 year after surgical binocular alignment. Normal flash visual evoked response binocular summation started in the range of facilitation (> 2.0) at 1 month of age and decreased to adult levels by 3.7 months of age. The shape of the flash visual evoked response binocular summation function obtained from the patients with early-onset esotropia, appeared similar to that of normal subjects; however, the rapid decrease in flash visual evoked response binocular summation from facilitation to normal adult levels occurred after surgical binocular alignment. In normal adults, flash visual evoked response binocular summation was significantly reduced by a 40-diopter base-in prism, suggesting that binocular misalignment was not the reason for the facilitation in flash visual evoked response binocular summation in either childhood population. It is proposed that this facilitation may reflect a process that leads to binocularity and that develops rapidly with binocular alignment.

Adolescent

Levodopa/carbidopa for childhood amblyopia.

PURPOSE: To evaluate the efficacy and tolerance of two low doses of levodopa/carbidopa (25/6.25 mg, 50/12.5 mg) and placebo (Tums) in 20 children with amblyopia between the ages of 4 and 14 years. METHODS: A double-masked placebo-controlled randomized 8-hour study was performed during which subjects received one of two doses of levodopa/carbidopa or placebo, combined with occlusion of the dominant eye. Visual acuity was measured at baseline and at 1 and 5 hours after capsule ingestion. Tolerance was assessed by questionnaire and physical examination. RESULTS: Visual acuity significantly improved by one line, from an overall average of 20/121 to 20/96, in the amblyopic eyes of both groups that received levodopa/carbidopa. Visual acuity did not significantly change in the placebo group. Tolerance was similar among all three groups. CONCLUSION: Average dose levels of 0.95/0.24 mg/kg and 1.94/0.49 mg/kg of levodopa/carbidopa were found to be well tolerated and efficacious at temporarily improving visual acuity in amblyopic eyes of children.

Adolescent

Electro-oculogram in vitamin A deficiency associated with cystic fibrosis. Short communication.

Electro-oculograms (EOGs) were recorded in a patient with cystic fibrosis and vitamin A deficiency before and during vitamin A supplementation (25,000 IU/day). Before vitamin A supplementation the EOG Arden light/dark ratio was 1.27. After seven months of vitamin A supplementation the Arden ratio increased to 3.0. These results reveal that vitamin A deficiency can cause an abnormal EOG.

Adolescent

Retinoblastoma, microphthalmia, coloboma, and neuroepithelioma of the pineal body.

A one-month-old infant boy was examined early in life because his mother had bilateral retinoblastoma and his father had bilateral microphthalmia. The ophthalmologist found his right eye was normal size with a coloboma of the iris, choroid, and retina. The left eye was microphthalmic with a coloboma of the uveal tract and retina. A vascularized fluffy white mass in the posterior pole was diagnosed clinically as a retinoblastoma. The tumor regressed with radiation. When the patient was four years of age, a large tumor was found in the region of the pineal recess, causing hydrocephalus and seizures. A biopsy showed an undifferentiated malignant neuroepithelial neoplasm. The patient died within three months of diffuse central nervous system tumor. The unusual findings of a retinoblastoma in a microphthalmic eye with bilateral colobomas and a neuroepithelial neoplasm of the pineal gland are discussed.

Abnormalities, Multiple

A prospective study of ocular abnormalities in hearing impaired and deaf students.

In a prospective study of 505 hearing impaired and deaf students conducted at Children's Hospital Eye Clinic, 48.7% were found to have significant ocular abnormalities. The prevalence of myopia, astigmatism, and pathological intraocular changes was found to be significantly increased over the general population. In addition, the prevalence of ocular abnormalities generally increased with the severity of the hearing loss. Of importance was the high prevalence of rubella-consistent abnormalities in the hearing impaired and deaf student populations. Rubella syndrome may be responsible for a major portion of high refractive errors and ocular pathological changes. It is recommended that ENT specialists and pediatricians be aware of the nearly 50% chance of ocular abnormality in hearing impaired and deaf students, and that ophthalmologic examination may be valuable for identification or confirmation of the etiology of hearing impairment.

Adolescent

Loss of contrast sensitivity in cystic fibrosis.

We measured the contrast sensitivity function in a 16-year-old boy with cystic fibrosis, before and during vitamin A supplementation. Before vitamin A supplementation, serum levels of vitamin A were abnormally low, the electroretinogram was reduced, and contrast sensitivity was abnormally low at all spatial frequencies. During vitamin A supplementation (25,000 IU/day), serum levels of vitamin A became low normal, the electroretinogram returned to normal, and the overall contrast sensitivity function improved by 94%. We propose that the contrast sensitivity function may be abnormal in patients with cystic fibrosis who have reduced retinal function secondary to vitamin A deficiency.

Adolescent

Contrast sensitivity of optokinetic nystagmus.

To determine the threshold characteristics of optokinetic nystagmus (OKN), contrast thresholds for involuntary OKN were measured for gratings of different spatial frequency to yield an OKN-contrast sensitivity function (OKN-CSF). The OKN-CSF resembled an inverted U-shaped function with temporal-to-nasal and nasal-to-temporal movement yielding similar functions. In addition, when psychophysical CSFs were determined for separate form and movement thresholds, it was discovered that the OKN-CSF approximated the psychophysical-movement CSF rather than the psychophysical-form CSF.

Adult

CSF interocular interactions in childhood ambylopia.

Contrast sensitivity functions (CSF's) were measured in the amblyopic and dominant eyes of 17 strabismic and 28 anisometropic children and in 19 similar age normal controls. A three-alternative forced-choice procedure was used to measure CSF's with the VCTS 6500. The results revealed reduced contrast sensitivity (CS) in both the amblyopic and dominant eyes of strabismic and anisometropic amblyopes compared to normal controls. Statistically significant intereye correlations of CS at each spatial frequency were found in all groups and in the presence of deep amblyopia, suggesting continued interocular interactions and binocularity. A separate longitudinal study of 7 of the amblyopes showed that, during the course of occlusion therapy, both the amblyopic and the dominant eyes improved in CSF. The results suggest that the amblyopic eye may influence CS in the dominant eye through interocular interactions. This process may serve to minimize CSF differences between the eyes and maximize binocular vision.

Amblyopia

Visual-evoked response binocular summation in normal and strabismic infants. Defining the critical period.

Pattern visual-evoked response binocular summation (VERBS) was recorded in normal infants, between the ages of 1-58 months, and in similar-aged esotropic infants before and at various times after corrective surgery. The normal subjects had no significant VERBS at 1.5 months of age, developed a rapid acceleration of VERBS between 1.5-3 months, and then gradually declined in VERBS from 3-58 months. The peak of the VERBS by age function at 3 months was well in the facilitation range (greater than 2.0) and corresponded to the general age range for the onset of binocular eye alignment, fusion, and stereopsis. The results from the early-onset esotropic patients revealed a similar function to that found in normal subjects; however, the function was triggered by surgical eye alignment. The peak of the VERBS function for esotropic subjects was lower than normal, and the initial rise was less rapid. It is proposed that the VERBS function reflects the human critical period for the development of binocular vision. In this framework, data from both infant developmental studies and adult studies were clarified.

Adolescent

The predictability of infant visual-evoked response testing on future visual acuity.

We reviewed the records of 27 infants with abnormal eye examinations and visual-evoked response (VER) testing (mean age, 10.5 months) who subsequently underwent a long-term follow-up ophthalmology examination (mean duration, 41 months). The infants were initially diagnosed with various ocular disorders including cortical blindness (eight), optic nerve hypoplasia (six), congenital cataract (two), and retinopathy of prematurity (one). Standard optotype visual-acuity determinations were available in the follow-up records of 11 children (21 eyes), and fixation behavior was obtained in the remaining 16 children (32 eyes). Results revealed that pattern-reversal VER P1 latency was predictive (87%) of whether visual acuity was equal to (or better than) or worse than 20/100 and whether a patient would have good fixation behavior (fix and follow, FF) or poor fixation (no FF) (86%) (P less than .001). Although flash VER P1 latency was also predictive of later visual acuity or good fixation (73%), it was not statistically significant. Pattern VER P1 amplitude and flash VER P1 amplitude were not predictive of later visual function. The predictive power of pattern VER P1 latency for later visual function probably relates to its reflection of macular function and low variability. An analysis of the variability of each of the four VER factors in normal infants (n = 50) indicated that pattern VER P1 latency was the least variable, and consequently most sensitive, VER factor for detecting and quantifying pathology. Overall, the results of this retrospective study suggest that pattern VER P1 latency may have important predictive power for later visual function in infants with an initially abnormal ophthalmologic examination.

Evoked Potentials, Visual

Management of strabismus with botulinum A toxin.

Three hundred eight patients with strabismus were treated with botulinum A toxin (Oculinum) chemodenervation; 153 were followed by the authors for at least 6 months. In this study group, 97 received botulinum A toxin injections as the primary method of treatment of their ocular deviation. Fifty-six received injections after traditional extraocular muscle surgery. Botulinum A toxin was useful for management of patients with recent surgical overcorrections and for management of some patients with sixth cranial nerve palsy. Chemodenervation of an extraocular muscle was not as successful as traditional strabismus surgery for treatment of infantile esotropia and other comitant deviations. Botulinum A toxin injection was ineffective in patients who had restrictive strabismus. This drug has limited application in the management of patients with strabismus.

Abducens Nerve

The contrast sensitivity function and childhood amblyopia.

We measured contrast sensitivity function and visual acuity in both eyes of strabismic and anisometropic amblyopic patients. There was a linear relationship between contrast sensitivity function and visual acuity in the amblyopic eye. As visual acuity decreased, the contrast sensitivity function decreased along the contrast sensitivity axis, and peak sensitivity shifted to lower spatial frequencies. After patching therapy, when visual acuity reached 20/20 in each eye, suggesting that the amblyopia was cured, there continued to be statistically significant difference in the contrast sensitivity functions between the eyes. The contrast sensitivity function from the previously amblyopic eye was depressed compared to the nonamblyopic eye. A comparison between patients with strabismic and anisometropic amblyopia showed that, when matched for visual acuity, the contrast sensitivity functions were similar for both the nonamblyopic and amblyopic eyes. However, a large difference was found between the amblyopic and nonamblyopic eyes of each group.

Amblyopia

Primary-position hypotropia after anterior transposition of the inferior oblique.

Three patients with fourth cranial nerve palsy underwent a recession of the ipsilateral inferior oblique muscle. In all three cases, the inferior oblique muscle was anteriorly displaced to the temporal border of the inferior rectus muscle. In the immediate postoperative period, all three patients developed a hypotropia and diplopia in the primary position with limitation of upgaze. The hypotropia remained stable and required retrodisplacement of the inferior oblique muscle in order to eliminate the diplopia. We emphasize the power of the anterior transposition of the inferior oblique muscle and caution its use as a unilateral procedure in patients with central fusion.

Adult

Treatment of corneal opacification in mucolipidosis IV with conjunctival transplantation.

Mucolipidosis IV is a rare, inherited metabolic storage disease producing progressive psychomotor retardation and congenital corneal clouding. Histopathologic studies have shown that the corneal epithelium is strikingly involved with intracytoplasmic vacuolated storage material with relative noninvolvement of the corneal stroma and endothelium. Additionally, it has been noted that epithelial removal results in corneal clarity. We treated a 28-month-old patient with mucolipidosis IV with conjunctival transplantation with donor conjunctiva from an unaffected sibling. Improved corneal clarity resulted and has persisted with a follow-up of one year.

Adult