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Biomedical subjects

Anne Moskowitz

Publications and source records attributed to Anne Moskowitz.

8 recordsLinked to original sources

Pediatric clinical visual electrophysiology: a survey of actual practice.

PURPOSE: Survey the actual clinical practice of pediatric visual electrophysiology. The electrophysiologists surveyed were members of the International Society for Clinical Electrophysiology of Vision (ISCEV). METHODS: A self-administered questionnaire with 55 items about visual evoked potential (VEP) and electroretinogram (ERG) testing of pediatric patients was sent to ISCEV members. The survey queried personnel, facilities, referral patterns and conduct of tests. RESULTS: Nearly all respondents (94%) had advanced scientific or clinical degrees or both, and most (96%) worked in academic or medical facilities. Of the 71 respondents, 68 tested patients 12 years or younger, and nearly all of those performed both VEPs and ERGs. However, fewer than a third did high volume (>10/month) testing of infants and young children (< or =6 years). Eye care professionals and neurologists made the majority (57%) of the referrals, with the most common reason for referral being suspected visual impairment. Conduct of a pediatric test session often required more than one practitioner. For both VEP and ERG, more than 70% of respondents required at least 30 min for each test. The majority indicated that they followed the ISCEV standards for stimuli and data acquisition. Almost all (94%) reported using the ISCEV recommended VEP electrode configuration. For ERG, most (88%) used ocular contact electrodes (including contact lens, thread, foil and HK loop), but 12% used skin electrodes exclusively and some (17%) used skin electrodes at times. CONCLUSIONS: Pediatric ERG and VEP testing is a labor intensive endeavor of highly trained professionals. ISCEV technical standards are typically met or exceeded, indicating that high quality testing of infants and children is feasible. Revision of the ISCEV ERG standard is necessary to bring actual practice into accord with evidence-based recommendations for infant testing.

Child↗

Multifocal ERG in subjects with a history of retinopathy of prematurity.

PURPOSE: Investigate the function of the central retina in subjects with a history of retinopathy of prematurity (ROP). METHODS: Multifocal electroretinogram (mfERG) responses to a scaled array of 103 hexagons were recorded in subjects, aged 11-23 years (N = 11), with a documented history of mild ROP. The amplitude and implicit time of the components (N(1), P(1), N(2)) of the first order kernel for six concentric rings were compared to those of control subjects (N = 9). RESULTS: The amplitude of each component varied significantly with eccentricity in both ROP and control subjects and was significantly smaller in the ROP subjects. The discrepancy between ROP and control subjects was greatest for central rings (1-3) and smaller for peripheral rings (4-6). The slopes of the functions summarizing log response density as a function of log eccentricity (degrees visual angle) were significantly shallower in ROP subjects. The implicit time of each component was longer in ROP subjects at all eccentricities. CONCLUSIONS: ROP associated alterations in neural retinal development may underlie the subtle macular dysfunction disclosed by the mfERG.

Adolescent↗

Development of the electroretinographic oscillatory potentials in normal and ROP rats.

PURPOSE: To study the development of the electroretinographic (ERG) oscillatory potentials (OPs) in rats and to compare normal OPs with those in a rat model of retinopathy of prematurity (ROP). METHODS: Following a longitudinal design, ERG responses to a greater than 5 log unit range of full-field stimuli were recorded in dark-adapted rats at postnatal day (P) 18, P31, P47, and P67. The ERG records were digitally filtered (60-235 Hz), and the trough-to-peak amplitudes and implicit times of OP2, OP3, OP4, and OP5 were measured. Additionally, rats with oxygen-induced retinopathy, a model of ROP, were studied at P31. RESULTS: Generally, OP amplitude increased and implicit time decreased with increasing stimulus intensity. The shape of the stimulus-response functions changed with age. The amplitudes of OP2, OP3, and OP4 were largest at P31. OP5 was largest at P47. All OPs were significantly affected in ROP rats; OP5 was least affected by ROP. CONCLUSIONS: A prolonged normal course of OP development, which featured waxing and waning of amplitudes, was observed and might have been consequent to maturation and then to final refinements of inner retinal circuitry. In ROP rats, marked attenuation of early OPs was consistent with persistent dysfunction of photoreceptors, and significant attenuation of the late OP5 was evidence of compromised function of inner retinal circuitry.

Aging↗

Development of visual acuity in children with cerebral visual impairment.

OBJECTIVE: To study the development of visual acuity in term-born children with cerebral visual impairment and a history of neonatal hypoxic-ischemic encephalopathy. METHODS: We studied 19 term-born children, aged 6 months to 6 years, with moderate to severe neonatal hypoxic-ischemic encephalopathy and behaviors indicative of cerebral visual impairment. Longitudinal measures of grating acuity were obtained using preferential looking (PL) and visual evoked potential (VEP) procedures. Visual acuities at first and last visits were compared. The courses of acuity development in the 9 children who underwent both VEP and PL acuity assessment at 4 or more ages were compared with normal development. RESULTS: All children had measurable PL and VEP acuity, despite poor visual behavior. In nearly all, both PL and VEP acuity were below normal for age. For both PL and VEP measures, acuity at the last visit was, on average, 1 octave better than at the first visit, with a rate of improvement lower than normal. Although parallel courses of PL and VEP development occurred in many, substantial disparities in PL and VEP acuity were observed in others. CONCLUSIONS: Modest increases in PL and VEP grating acuity occur during early childhood in many of these patients. The rate of increase is lower than normal.

Blindness, Cortical↗

Early ametropia and rod photoreceptor function in retinopathy of prematurity.

PURPOSE: Early ametropia, particularly myopia, is frequent in children with a history of preterm birth and retinopathy of prematurity (ROP). The retina is known to govern eye growth and refractive development. We tested the hypothesis that deficits in retinal function are significantly associated with early ametropia in ROP subjects. METHODS: Scotopic electoretinogram (ERG) responses to full field stimuli were studied in 40 ROP subjects aged 8 weeks to 18 years. The ROP was categorized as treated, untreated, or none. Refractive development of each ROP subject was monitored and compared with normal for age. The rod photoresponse parameters were calculated and the postreceptoral responses derived. The ERG parameters in the ROP subjects were compared with normal values for age. RESULTS: Twelve ROP subjects developed early ametropia, 10 myopia, and two hyperopia. In the majority of ROP subjects, receptoral and postreceptoral response parameters were below the normal mean for age. In the 12 children with early ametropia, rod photoreceptor sensitivity was significantly lower than in emmetropic ROP subjects; and in five tested in infancy, deficits in rod photoreceptor sensitivity antedated development of ametropia. The myopic control subjects had no deficits in response parameters. CONCLUSIONS: Retinal dysfunction is significantly associated with early ametropia in these ROP subjects. Thus, mechanisms for the development of ametropia in ROP subjects may involve rod and rod-mediated postreceptoral activity.

Adolescent↗

Diagnosis of plus disease in retinopathy of prematurity using Retinal Image multiScale Analysis.

PURPOSE: To evaluate a semiautomated image analysis software package, Retinal Image multiScale Analysis (RISA), for the diagnosis of plus disease in preterm infants with retinopathy of prematurity (ROP). METHODS: Digital images of the posterior pole showing both disc and macula in preterm infants with ROP were analyzed with an enhanced version of RISA. Venules (N = 106) and arterioles (N = 44) were identified, and integrated curvature, diameter, and tortuosity of the vessels were calculated. After the RISA calculations were completed, the origins of the vessels were determined to be 32 eyes in 16 infants (12 eyes with plus disease, 20 with no plus disease, as diagnosed by ophthalmic examination). Vessels were sorted into two groups-plus disease and no plus disease-and each RISA parameter was compared using the Mann-Whitney test. For each parameter, sensitivity and specificity were plotted as a function of cutoff criterion, receiver operating characteristic (ROC) curves were constructed, and the areas under the curve (AUC) were calculated. RESULTS: For both arterioles and venules, each of the three parameters was significantly larger for the plus disease group. For instance, the median estimated arteriolar and venular diameters were approximately 12 mum greater in plus disease. Sensitivity and specificity plots indicated good accuracy of each parameter for the diagnosis of plus disease. The AUC showed that curvature had the highest diagnostic accuracy (0.911 for arterioles, 0.824 for venules). CONCLUSIONS: The strong performance of RISA parameters in this sample suggests that RISA may be useful for diagnosing plus disease in preterm infants with ROP.

Area Under Curve↗

ERG oscillatory potentials in infants.

PURPOSE: Study the scotopic and photopic oscillatory potentials (OPs) of the electroretinogram (ERG) in 10-week old infants. METHODS: Term-born 10-week old infants (n = 15) and adults (n = 12) were tested. Full-field ERGs were recorded under scotopic and photopic conditions. The records were filtered (75-300 Hz) to demonstrate the oscillatory wavelets. The amplitudes and implicit times of the infants' OPs were compared to those in adults and also to amplitudes of the saturated photoreceptor responses. RESULTS: In infants, the mean OP amplitudes are similar in scotopic and photopic conditions and do not vary significantly with OP number. Infants' OPs are significantly smaller than in adults, with scotopic OPs averaging 19% of that in adults and photopic OPs averaging 47%, whereas the amplitudes of the saturated photoreceptor responses are 43% and 66% of those in adults. Mean interpeak intervals are similar in infants and adults, indicating oscillatory behavior at a frequency of 155 Hz in scotopic conditions and 135 Hz in photopic conditions. CONCLUSIONS: In young infants, the OPs are relatively immature compared to the photoreceptor responses, with the immaturity of the scotopic responses being more marked than that of the photopic responses.

Adaptation, Ocular↗