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Janet S Sunness

Publications and source records attributed to Janet S Sunness.

14 recordsLinked to original sources
PubMed2005

Extreme hyperopia is the result of null mutations in MFRP, which encodes a Frizzled-related protein.

Nanophthalmos is a rare disorder of eye development characterized by extreme hyperopia (farsightedness), with refractive error in the range of +8.00 to +25.00 diopters. Because the cornea and lens are normal in size and shape, hyperopia occurs because insufficient growth along the visual axis places these lensing components too close to the retina. Nanophthalmic eyes show considerable thickening of both the choroidal vascular bed and scleral coat, which provide nutritive and structural support for the retina. Thickening of these tissues is a general feature of axial hyperopia, whereas the opposite occurs in myopia. We have mapped recessive nanophthalmos to a unique locus at 11q23.3 and identified four independent mutations in MFRP, a gene that is selectively expressed in the eye and encodes a protein with homology to Tolloid proteases and the Wnt-binding domain of the Frizzled transmembrane receptors. This gene is not critical for retinal function, as patients entirely lacking MFRP can still have good refraction-corrected vision, produce clinically normal electro-retinograms, and show only modest anomalies in the dark adaptation of photoreceptors. MFRP appears primarily devoted to regulating axial length of the eye. It remains to be determined whether natural variation in its activity plays a role in common refractive errors.

Animals↗
PubMed2005

Long-term follow-up of fixation patterns in eyes with central scotomas from geographic atrophy that is associated with age-related macular degeneration.

PURPOSE: To study whether fixation patterns changed over time in patients with central scotomas from geographic atrophy from age-related macular degeneration. DESIGN: Prospective cohort study. METHODS: setting: Institutional. patient or study population: Prospective natural history study of geographic atrophy included 34 eyes of 25 patients with baseline acuity between 20/80 and 20/200 and with subsequent follow-up. observation procedures: Baseline and annual follow-up visits included best-corrected visual acuity, scanning laser ophthalmoscope macular perimetry, reading rate, and clinical evaluation. main outcome measures: Location of eccentric preferred retinal locus for fixation (PRL). RESULTS: At baseline, 77% of study eyes had a PRL. At the final visit (median follow-up, 5.3 years), 91% of study eyes had a PRL, with 81% of the eyes retaining the baseline PRL location. Fixation with the scotoma to the right and fixation with the scotoma superior were the first and second most common fixation patterns, respectively. Reading rates of <50 words/min were present in 54% of eyes. Eyes fixating with the scotoma to the left tended to have lower reading rates than eyes fixating with right or superior patterns. CONCLUSION: Fixation with right pattern remained the most common fixation pattern, both in patients with a PRL at baseline and in patients who had a PRL during follow-up. Eyes with a PRL at baseline generally retained this pattern. The reading rate data suggest an advantage of fixation with right or superior pattern, rather than left. Reading rate declined further during follow-up in most patients.

Aged↗
PubMed2004

Red contact lenses for alleviation of photophobia in patients with cone disorders.

PURPOSE: To describe the use of red contact lenses to alleviate photophobia in patients with cone disorders. DESIGN: Retrospective interventional case series. METHODS: Twenty-three patients with achromatopsia or an acquired cone disorder with complaints of severe photophobia were fit with absorptive red soft contact lenses to alleviate photophobia and improve their ability to use their remaining vision more effectively RESULTS: The contact lenses immediately resolved the aversion to light, with dramatic improvement in visual function in all patients (determined by observation of the patient and by patient report). It allowed eight patients to become eligible to drive. CONCLUSIONS: Red contact lenses successfully alleviate photophobia in patients with cone disorders.

Adolescent↗
PubMed2004

Retinotopic mapping of the visual cortex using functional magnetic resonance imaging in a patient with central scotomas from atrophic macular degeneration.

PURPOSE: To describe retinotopic mapping of the visual cortex when a central scotoma is present. DESIGN: Single observational case report. METHODS: Scanning laser ophthalmoscope perimetry was used to define the site and stability of fixation and the area of dense scotoma. Functional magnetic resonance imaging of the visual cortex was performed while the patient viewed an expanding annular stimulus. RESULTS: Retinotopic mapping of the visual cortex for a patient with a horseshoe scotoma from geographic atrophy involving the macular region showed a loss of stimulation to the cortical areas representing the site of the atrophic lesion. CONCLUSIONS: Cortical retinotopic mapping can be performed successfully in patients with central scotomas from macular disease. This study can serve as a basis for the future investigation of cortical plasticity in visual cortex.

Brain Mapping↗
PubMed2003

Characteristics of visual loss by scanning laser ophthalmoscope microperimetry in eyes with subfoveal choroidal neovascularization secondary to age-related macular degeneration.

PURPOSE: To evaluate the effects of subfoveal choroidal neovascularization secondary to age-related macular degeneration on functional parameters obtained by scanning laser ophthalmoscope microperimetry. DESIGN: Retrospective observational case series and cross-sectional study. METHODS: At the Doheny Retina Institute and Wilmer Eye Institute a consecutive series of 179 eyes of 175 patients with subfoveal choroidal neovascularization secondary to age-related macular degeneration was studied. The onset of visual symptoms, best-corrected visual acuity, fluorescein angiography, evaluation of fundus microperimetry and fixation pattern using the Rodenstock scanning laser ophthalmoscope were obtained for each patient. The main outcome measures were central retinal sensitivity and fixation pattern (fixation location and fixation stability) in eyes with subfoveal choroidal neovascularization and their relationship to the length of disease, type and characteristics of choroidal neovascularization, and visual acuity. RESULTS: Of 179 eyes, 135 (75%) had central fixation, 27 (15%) had poor central fixation, and 17 (9%) had predominantly eccentric fixation. Seventy-six eyes (42%) had stable fixation, 70 eyes (39%) had relatively unstable fixation, and 33 eyes (18%) had unstable fixation. In 50 eyes (28%) a dense central scotoma was noted. Eighty-nine of 100 eyes (89%) with length of symptoms of less than 3 months had predominantly central fixation and 58 (58%) had stable fixation; 14 of 34 eyes (41%) with length of symptoms of more than 6 months had predominantly central fixation, and 5 eyes (15%) had stable fixation. In 15 eyes of patients who elected not to receive treatment, successive scanning laser ophthalmoscope microperimetry were obtained over time (follow-up of 18 months after onset of symptoms). Three months or less after the onset of symptoms, 13 eyes (87.7%) had predominantly central fixation and 9 eyes (60%) had stable fixation. More than 3 months and 6 months or less after the onset of symptoms, 10 eyes (66.7%) had predominantly central fixation and 7 eyes (46.7%) had stable fixation. This trend was further demonstrated in eyes more than 6 months after the onset of symptoms. CONCLUSIONS: We conclude that the sequence of events leading to visual function deterioration appears to involve an initial mild decrease in central retinal sensitivity and visual acuity followed by progressive fixation instability and, ultimately, development of an absolute central scotoma with totally eccentric fixation. Increased length of disease is associated with worse fixation pattern and retinal sensitivity deterioration as assessed by scanning laser ophthalmoscope microperimetry. A better understanding of the characteristics of visual loss assessed by fixation pattern evaluation and microperimetry in age-related macular degeneration may help optimize timing, patient selection, and treatment options in eyes with this condition.

Aged↗
PubMed2003

In vivo micropathology of Best macular dystrophy with optical coherence tomography.

Best macular dystrophy (BMD) is an autosomal dominant retinopathy caused by mutations in the VMD2 gene that encodes a chloride channel in the basolateral membrane of the retinal pigment epithelium (RPE). BMD patients were studied using optical coherence tomography (OCT) to understand the disease process in the macula leading to vision loss. BMD patients (ages 5-61), representing four families with known VMD2 mutations, were included. OCT scans were recorded in the central retina and longitudinal reflectivity profiles were analysed. The central retina in BMD showed different OCT abnormalities at or near the level of the highly reflective deep retinal band termed the outer retina-choroid complex (ORCC). Two types of ORCC change were noted to occur either separately or together: (1) splitting with or without intervening hyporeflective areas; and (2) elevation. Longitudinal study of a BMD patient indicated that such abnormalities were dynamic and changed in type and degree with time. The pathogenetic sequence in BMD may begin with defective fluid transport across the RPE secondary to the channelopathy in the basolateral membrane. In the macula, this leads to an abnormal interface with adjacent structures at both apical and basal surfaces of the RPE. The disease process results in detachments of the neurosensory retina, such as in central serous chorioretinopathy, and sub-RPE pathology resembling some stages of age-related macular degeneration, with eventual loss of photoreceptors, inner retina and central vision.

Adult↗
PubMed2002

Electroretinographic abnormalities in parents of patients with Leber congenital amaurosis who have heterozygous GUCY2D mutations.

BACKGROUND: Leber congenital amaurosis (LCA) is an infrequently encountered congenital form of retinitis pigmentosa with marked genetic and clinical heterogeneity. Thus far, 10 genes have been identified in this disorder since 1996. In the future, LCA may become treatable by gene and/or pharmacological intervention, and these therapies will likely be gene specific, giving major significance to rapid gene identification and gene-phenotype studies. OBJECTIVE: To test the hypothesis that parents of patients with LCA have identifiable electroretinographic and psychophysical changes. SUBJECTS, MATERIALS, AND METHODS: Complete eye examinations and electroretinographic studies were performed on 2 sets of parents whose offspring were diagnosed as having LCA and who were found to carry a mutation in 1 of the 10 LCA genes-GUCY2D. One set of parents also underwent static perimetry threshold measurements. RESULTS: We found that single flash-light-adapted a- and b-wave amplitudes, 30-Hz flicker, or both cone signals were significantly decreased in amplitude in 4 heterozygotes, while 2 parents showed delayed 30-Hz flicker implicit times. Electroretinographic rod-mediated signals were normal in 2 of the heterozygotes, but subnormal in 2. Static perimetry testing showed normal thresholds in the 2 heterozygotes tested. MAIN OUTCOME MEASURES: Single flash-light-adapted a- and b-wave amplitudes and implicit times, 30- or 32-Hz flicker amplitudes and implicit times, rod-mediated signals, and dark-adapted, rod-mediated thresholds. CONCLUSIONS: Some carrier parents of patients with LCA and a GUCY2D mutation develop measurable, cone and possibly rod abnormalities most consistent with a mild cone-rod dysfunction. This correlates well with the known retinal expression pattern of GUCY2D, which is considerably higher in cone compared with rod photoreceptor cells.

Adaptation, Ocular↗
PubMed2002

Limited macular translocation for atrophic maculopathy.

OBJECTIVES: To report visual improvement following bilateral limited macular translocation for a patient with atrophic macular disease, and to discuss issues related to the selection of potential candidates for this technique. DESIGN: Case report. RESULTS: A 78-year-old woman with bilateral atrophic maculopathy and no choroidal neovascularization had slowly progressive loss of visual acuity for at least 17 months in the right eye and 25 months in the left eye. She underwent bilateral limited macular translocation, using scleral infolding in the right eye and scleral outpouching in the left eye. Following translocation of her maculae, her best-corrected visual acuity improved from 20/200 to 20/30 OD and from 20/180 to 20/100 OS. She remained stable during 30 months of follow-up for the right eye and 22 months of follow-up for the left eye. CONCLUSION: Macular translocation may allow visual recovery in selected patients with atrophic maculopathy, even after a prolonged period of poor vision.

Aged↗
PubMed2002

Quantifying changes in RPE and choroidal vasculature in eyes with age-related macular degeneration.

PURPOSE: An image-analysis technique was developed to quantify changes in the retinal pigment epithelium (RPE) and choriocapillaris in eyes of deceased donors with age-related macular degeneration (AMD). METHODS: Both eyes of two donors with AMD and of one normal control donor were used to develop this technique. After removal of the anterior segments, the eyecups were hemisected through the macula, with the disc included in one half of the eyecup. The choroid with RPE cells was dissected from the sclera and incubated for alkaline phosphatase (APase) activity, and the pigment was partially bleached with H2O2. The APase-incubated choroid was flat embedded and sectioned after image and morphometric analyses. Quantitative computer-assisted morphometric analyses of the two AMD-affected eyes (cases 1 and 2) were compared with analysis of the normal eye of a 70-year-old control subject (case 3). RESULTS: The right eye in case 1 had geographic atrophy (GA) and demonstrated a large area in the posterior pole with very few RPE cells (90% loss of RPE), but the border of the area of RPE atrophy was not well defined. The density of choroidal blood vessels in this area was reduced 30% to 50%, compared with the same regions in the control eye. No area was completely devoid of choriocapillaris. Clinically undetected choroidal neovascularization (CNV) was observed in the right eye in case 1 in both the periphery and the macula and was generally associated with surviving RPE cells. The right eye in case 2 had GA (areolar RPE atrophy) and demonstrated a reduction in vascular density in the area from disc to macula that was even greater than that in the eye in case 1 (53% reduction in the submacular region). RPE atrophy between the disc and macula was almost complete. The border of the RPE defect was clearly delineated and coincided closely with the area of decreased choroidal vascular density. Surviving choriocapillaris in the area of RPE atrophy was significantly narrower than choriocapillaris in the control subject and in normal areas of the eyes with GA (P < 0.0001). CONCLUSIONS: In these eyes with GA, RPE atrophy was more severe than loss of choriocapillaris. Surviving choriocapillaris in areas with complete RPE loss was highly constricted. The association of surviving RPE cells with CNV suggests that RPE cells may furnish a stimulus for new vessel formation or stabilization.

Aged↗
PubMedDate not supplied

Issues in quantifying atrophic macular disease using retinal autofluorescence.

PURPOSE: To demonstrate the potential and limits of autofluorescence imaging in identifying and delineating areas of atrophy. METHODS: Fundus photographs and infrared scanning laser ophthalmoscope (SLO) imaging, SLO macular perimetry, and SLO autofluorescence imaging results were compared for two patients with geographic atrophy (GA) from age-related macular degeneration, one patient with pigmentary alteration of the retina, and two patients with Stargardt disease. The main outcome measure in this case series was the presence of reduced autofluorescence. RESULTS: Drusen may become undetectable during autofluorescence imaging for some patients, allowing simple identification of areas of GA with areas of reduced autofluorescence. In other patients, drusen themselves have decreased autofluorescence, despite having intact retinal function in the retina overlying them. Some patients may have areas of reduced autofluorescence that persist for many years, without evidence of the development of atrophy. In Stargardt disease, decreased autofluorescence can easily detect and delineate areas of scotoma. Areas with mottled autofluorescence may have overlying function, but the function may not be adequate to support a fixation locus in that area. CONCLUSIONS: Using decreased autofluorescence to delineate areas of atrophy may be helpful in atrophic macular disorders. For GA, correlation with fundus photographs or macular perimetry findings may be necessary to differentiate between drusen and atrophy. For Stargardt disease, the nature of areas of decreased autofluorescence may help explain visual function of those areas.

Aged↗