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Biomedical subjects

M E Hartnett

Publications and source records attributed to M E Hartnett.

At least 19 recordsLinked to original sources
PubMed2000

Infrared scanning laser tomography of macular cysts.

OBJECTIVE: To perform three-dimensional, noninvasive, quantitative analysis of cystoid macular edema and macular cysts using infrared scanning laser tomography and to correlate findings with visual acuity (VA) as a basis for interventional studies. DESIGN: Cross-sectional, nonrandomized study. PARTICIPANTS: Seventeen patients (29-86 years of age) with macular cysts associated with a broad spectrum of diseases. INTERVENTION: Confocal infrared imaging with scanning laser tomography with the TopSS (790 nm) (Laser Diagnostic Technologies, San Diego, CA) with digitized images was used to perform three-dimensional, quantitative analysis of cysts in the central 5 degrees of the macula. MAIN OUTCOME MEASURES: Measurements of macular cyst number, area, volume, depth, slope, height of the surrounding macular elevation, and correlation with VA. RESULTS: Scanning laser tomography detected macular cysts in all patients. The number per patient ranged from 1 through 15. Cysts were accompanied by surrounding macular elevation in 16 patients (mean macular height, 216 microm). The area covered by cysts in the central 5 degrees was 0.087 to 0.969 mm2, and volume was 0.007 to 0.549 mm3. Visual acuity was significantly poorer in patients with greater cyst area (P = 0.0007), cyst volume (P = 0.0009), macular thickening (P = 0.0002), and cyst depth (P = 0.0013). Cyst number, average slope, and maximum slope, however, did not correlate significantly with VA. Grouping of macular cysts according to macular height and average cyst depth revealed that cysts in a more thickened retina were significantly deeper, had steeper slopes, and corresponded to worse VA. Macular height and average cyst depth were highly associated with each other, suggesting that in eyes with surrounding macular edema, cysts were deeper and may reflect more widespread tissue destruction. Individual confocal tomographic images provided additional information. Neither ophthalmoscopy nor fluorescein angiography delineated features such as retinal folds that suggested vitreous traction or changes in deeper layers that suggested occult choroidal new vessels. CONCLUSIONS: Infrared scanning laser tomography is a rapid and noninvasive imaging method that provides quantitative analysis of macular cysts in addition to qualitative information not seen clinically. Because poor VA is related to severe involvement of the central retina, scanning laser tomography could provide an objective outcome measure for interventional studies.

Adult↗
PubMed2000

Serum markers of oxidative stress and severity of diabetic retinopathy.

OBJECTIVE: To compare serum markers of oxidative stress with diabetic retinopathy severity RESEARCH DESIGN AND METHODS: This cross-sectional study compared patients with types 1 and 2 diabetes with control subjects in western New York and Pennsylvania. Retinopathy severity was graded from funduscopic fields based on the Early Treatment of Diabetic Retinopathy Study. Serum samples were analyzed for thiobarbituric acid-reacting substances (TBARS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, creatinine, HbA1, and triglycerides. Appropriate analysis of covariance models were performed. RESULTS: TBARS (P = 0.019), triglyceride (P = 0.004), and glucose and HbA1 (both P<0.001) levels were elevated in diabetic patients compared with those in control subjects. SOD (P = 0.003) and GSH-Px (P = 0.046) levels were lower in diabetic patients than in control subjects. No correlation existed between SOD levels and either glucose or HbA1 levels. No significant associations existed between levels of TBARS, SOD, or GSH-Px and severity of diabetic retinopathy There was a significant association between poorer visual acuity and worse retinopathy (P = 0.009), which was only partly explained by macular edema. CONCLUSIONS: Increased levels of TBARS and decreased levels of SOD and GSH-Px were found in diabetic patients compared with those in control subjects, but no significant associations were found between the levels of these substances and severity of retinopathy When duration and type of diabetes and serum HbA1 levels were taken into account, only visual acuity remained associated with more severe retinopathy.

Adolescent↗
PubMed1999

Infrared imaging of cystoid macular edema.

BACKGROUND: Cystoid macular edema (CME), a cause of central visual loss, is described in various pathologies. Typically, the fluorescein angiogram confirms the diagnosis and provides qualitative information as to the extent of leakage. This study was performed to investigate the features of cysts and quantify the extent of CME using non-invasive infrared imaging. METHODS: Eighteen eyes of 16 successive patients with CME in association with a broad spectrum of diseases were included in the study. The diagnosis of CME was established clinically and confirmed by fluorescein angiography. Digital infrared imaging was performed with a research scanning laser ophthalmoscope with different apertures, providing direct confocal and indirect imaging modes, to discriminate superficial features from deeper ones and to emphasize sources of multiple laterally scattered light. RESULTS: CME was easily detected with infrared imaging in all eyes. Confocal mode visualized the cysts themselves, while indirect mode emphasized borders. Large central cysts were detected as distinct, non-confluent structures. In addition, folds detected with infrared imaging in the macula in 12 of the 18 eyes were not always observed clinically. CONCLUSION: Infrared imaging provides a quick and safe diagnostic tool for patients with CME. The cystoid structures are readily localized and quantified, useful for monitoring CME. Despite differences in the pathophysiology, cysts did not differ qualitatively in a variety of diseases with infrared imaging.

Adult↗
PubMed1999

Spatial extent of pigment epithelial detachments in age-related macular degeneration.

OBJECTIVE: To quantify the spatial extent of pigment epithelial detachment (PED) associated with age-related macular degeneration (AMD) using a rapid, noninvasive method. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: The authors tested 32 eyes of 21 patients (13 women and 8 men) with AMD 56 to 91 years of age (mean = 72.8 years). The authors retested seven eyes of six patients. INTERVENTION: Three-dimensional imaging and quantification of PED were performed in each subject using confocal infrared imaging (790 nm) with a Topographic Scanning System (TopSS). The data consisted of a series of 32 images within a 3-mm-depth range requiring 0.9 second. Three-dimensional calculations were made from the series. MAIN OUTCOME MEASURE: Height, diameter, area, volume, and slope of each PED were obtained with two calculation methods. The Ellipse Method used a graphics tool to draw elliptical borders circumscribing the region of interest in the image. The software automatically calculated the values for all parameters for the region inside the ellipse, with the retinal reference plane adjusted to match the height of the surrounding retina. The User-Defined Region Method differed in that the region of interest was drawn manually. RESULTS: PEDs were easily detected in all patients using the TopSS. Maximum height of all PEDs above the reference plane ranged from 0.204 to 1.818 mm (mean = 0.57 mm). The diameter was 0.501 to 5.151 mm (mean = 2.711 mm), area was 0.179 to 20.402 mm2 (mean = 6.585 mm2), and volume was 0.012 to 13.981 mm3 (mean = 2.173 mm3). Intraobserver variability was low, with correlations between first and second measurements for the first visit ranging from r = 0.906 to 0.997 for slope and diameter, respectively. CONCLUSIONS: Three-dimensional analysis with the TopSS provides objective outcome measures not obtainable with typical clinical methods such as fundus photography and angiography. Height and volume are crucial in determining whether neovascularization is worsening or persistent after photocoagulation. More longitudinal data are needed to determine whether tomographic data reduce the need for angiography. Unique to scanning laser tomography, exudative features were imaged at different depths.

Aged↗
PubMed1999

Release of bFGF, an endothelial cell survival factor, by osmotic shock.

PURPOSE: To test the effects of osmotic change on basic fibroblast growth factor (bFGF) release from cultured endothelial cells (ECs). METHODS: Bovine aortic and bovine retinal ECs were exposed to hypoosmotic shock for 2 minutes, were allowed to recover for 15 minutes, and had bFGF release assayed. The role of bFGF in cell recovery was assessed by including neutralizing antibody against bFGF or the addition of exogenous bFGF. Cell number and viability were determined under varying conditions. Apoptosis was assessed by immunoperoxidase detection of digoxigenin-labeled DNA. RESULTS: After shock and recovery, both ECs released significantly greater amounts of bFGF than untreated control. bFGF release after shock for 2 minutes was lower than release after shock and recovery. Bovine retinal endothelial (BRE) cell number was reduced at 48 hours after shock, recovery, and removal of released bFGF compared with cells left in the presence of released bFGF. Cell number was significantly lower when BRE cells were shocked and recovered in the presence of a neutralizing anti-bFGF antibody (P<0.05). Exogenous bFGF reversed this effect. Apoptosis was significantly increased in BRE cells shocked and recovered or in the presence of bFGF antibody (P<0.001). CONCLUSIONS: bFGF is released by cultured ECs in response to osmotically induced cell injury. These results support the concept of bFGF as a "wound" hormone and survival factor for ECs. In further compromised tissue, release of bFGF in this manner may play a role in the pathogenesis of disease.

Animals↗
PubMed1998

Cyanoacrylate glue in the repair of retinal detachment associated with posterior retinal breaks in infants and children.

PURPOSE: To share the authors' experience with cyanoacrylate glue in posterior retinal breaks associated with retinal detachments in infants and children. METHODS: A retrospective study was performed of four consecutive pediatric patients who underwent vitreoretinal surgery for retinal detachment associated with posterior retinal breaks, for which cyanoacrylate glue was used. RESULTS: In three of the four patients, successful retinal reattachment with visual function was achieved by vitreoretinal surgery and cyanoacrylate placed on the apposed edges of posterior retinal breaks or used to plug a break (postoperative follow-up was 1.5-2 years). In two successful cases, the glue was applied onto the break while the retina was detached, which resulted in closure of the retinal breaks and reattachment of the retina in both cases. CONCLUSIONS: Cyanoacrylate creates a permanent closure of retinal breaks and may be useful in select cases of infant retinal detachment with posterior retinal breaks in which current available treatment failed or would fail.

Administration, Topical↗
PubMed1997

Quantitative analysis of macular holes with scanning laser tomography.

OBJECTIVE: The purpose of the study is to establish objective, quantitative, and reproducible three-dimensional analysis for macular holes with scanning laser tomography and to correlate measurements with visual acuity. DESIGN: The authors performed a cross-sectional, nonrandomized study. PARTICIPANTS: The authors examined 28 full-thickness macular holes of 23 patients aged 61 to 84 years. INTERVENTION: Confocal infrared imaging with scanning laser tomography using the TopSS (790 nm, 10 degrees field) three-dimensional measurements and macular hole analysis were performed. MAIN OUTCOME MEASURES: Area, depth, and volume parameters for both macular holes and rims were obtained in two ways: (1) reference plane for analysis equal to height of the retina (offset surface distance [OSD] 0) or (2) equal to height of the surrounding edematous rim of the hole (OSD user). Correlation of measurements with visual acuity and groups of macular holes was performed. Reproducibility from three image series per subject and intraobserver variability from ten measurements in four subjects were computed. RESULTS: Scanning laser tomography could detect macular hole and rim features in all subjects. Infrared images provided clinically useful information that may help explain macular hole pathophysiology. Based on quantitative, three-dimensional measurements, holes were assigned to four groups: large, small, shallow, and average. Groups varied significantly (P < 0.05) for the majority of measurements. Visual acuity correlated significantly (P < 0.05) with macular hole volume, depth, slope, and rim height with OSD user only, but not with hole area. Holes computed with OSD user were deeper and of greater volume. Reproducibility was excellent for hole area, slope, and rim area; good for hole volume and depth; variable for rim volume; and improved with OSD user. Intraobserver variability was low in each group. CONCLUSIONS: Scanning laser tomography is a reproducible three-dimensional imaging technique providing objective and quantitative clinical information in assessing, grouping, and managing macular holes. By setting the OSD to rim height, additional information of rim height and hole volume was provided and correlated with visual acuity. In addition, more reliable differences among macular hole groups were found. Axial measurements such as macular hole depth, volume, and rim height may be more important for visual acuity than hole area indicating their possible predictive value for outcome measures.

Aged↗
PubMed1996

Deep retinal vascular anomalous complexes in advanced age-related macular degeneration.

PURPOSE: The authors describe the clinical characteristics of a group of patients with age-related macular degeneration (AMD), deep retinal vascular anomalous complexes (RVACs), advanced Bruch membrane changes, and severe visual loss. Based on clinical evaluation and imaging studies, the authors hypothesize the cause of such retinal vascular formations. PATIENTS AND METHODS: The authors quantified an initial case series of 6 patients and expanded it to 11 patients (14 eyes) with AMD and RVACs diagnosed by fluorescein angiography or slit-lamp examination. Associated pigment epithelial detachments (PEDs) of 13 eyes are described. In addition to the clinical and fluorescein angiography descriptions, infrared imaging and indocyanine green angiography were used to characterize more recently described RVACs and fellow eyes. RESULTS: Each study eye had a clearly defined anastomosis connecting the retinal circulation to a vascular complex in the deep retina. The RVACs associated with PEDs assumed a more central location than did typical choroidal neovascularization associated with PEDs. In seven eyes with RVACs, there were clinically recognizable retinovascular findings: intraretinal hemorrhages, telangiectasia, or microaneurysms. Legal blindness occurred in 9 of 11 patients. CONCLUSION: These results indicate that retinovascular changes can be associated with nondisciform AMD. The authors speculate that neurodegenerative changes and hypoxia may lead to such changes, the RVAC being a more advanced finding. Closure of an RVAC with photocoagulation is difficult, perhaps because of its higher blood flow. The visual outcome is poor, not only because of the advanced state of the underlying AMD, but also because of the exudative nature of the RVAC.

Aged↗
PubMed1996

Characteristics of exudative age-related macular degeneration determined in vivo with confocal and indirect infrared imaging.

PURPOSE: To evaluate the current and future interventions in age-related macular degeneration (AMD), it is essential to delineate the early clinical features associated with later visual loss. The authors describe the retinal pigment epithelium (RPE)/Bruch membrane region in ten patients with advance exudative AMD using current angiographic techniques and a noninvasive method: infrared (IR) imaging with the scanning laser ophthalmoscope. METHODS: Ten patients with exudative AMD, evidence by choroidal neovascularization (CNV), fibrovascular scar formation, pigment epithelial detachment, or serous subretinal fluid,were examined using IR imaging, fluorescein angiography, indocyanine green angiography, and stereoscopic viewing of fundus slides. The authors determined the number and size of drusen and subretinal deposits and the topographic character of the RPE/Bruch membrane area and of CNV. RESULTS: In all patients, IR imaging yielded the greatest number of drusen and subretinal deposits. Sheets of subretinal material, but few lesions consistent with soft drusen, were seen. Infrared imaging provided topographic information of evolving CNV. Choroidal neovascularization appeared as a complex with a dark central core, an enveloping reflective structure which created a halo-like appearance in the plane of focus, and outer retinal/subretinal striae. CONCLUSIONS: Infrared imaging provides a noninvasive, in vivo method to image early changes in the RPE/Bruch membrane. It offers advantages over current imaging techniques by minimizing light scatter through cloudy media and enhancing the ability to image through small pupils, retinal hyperpigmentation, blood, heavy exudation, or subretinal fluid. It provides additional information regarding early CNV, and the character of drusen and subretinal deposits.

Aged↗
PubMed1996

Difficulties in excluding the diagnosis of retinoblastoma in cases of advanced Coats' disease: a clinicopathologic report.

We highlight the difficulty in differentiating Coats' disease from retinoblastoma. Two patients with bullous exudative retinal detachment and abnormal vessels are discussed. Histologic evaluation of the 5-year-old patient revealed retinoblastoma. The 1-year-old patient had Coats' disease by histologic identification. With this in mind, we suggest enucleation of such eyes if diagnostic uncertainty exists, since failure to treat retinoblastoma is a more serious error than enucleation of an eye with minimal function.

Calcinosis↗
PubMed1993

Glaucoma as a cause of poor vision in severe retinopathy of prematurity.

Despite surgical reattachment of the retina in infants with severe retinopathy of prematurity (ROP), visual acuity may decline. We performed gonioscopy and applanation tonometry on 26 eyes of 17 infants with severe ROP who were randomly selected and followed prospectively for 2 years. Of these 26 eyes, one eye of one patient had only peripheral retinocryopexy for threshold stage III disease and had an attached retina before enrollment into the study. Sixteen infants subsequently underwent vitrectomy, scleral buckle, or both. Retinal reattachment of the posterior pole was present in at least one eye each of 10 of the 17 infants. Glaucoma was diagnosed in 5 of the 10 patients; all 5 showed a decrease in visual acuity of greater than 1 octave. Of the 5 infants without glaucoma, 3 showed visual improvement, and 2 remained the same. Although we studied a small number of cases, our results suggest that glaucoma may be a cause of visual decline in infants with severe ROP. A decline in visual acuity in infants with severe ROP and surgical retinal reattachment may warn us of glaucoma, as this diagnosis is difficult to make in these small infants.

Child, Preschool↗
PubMed1992

Classification of retinal pigment epithelial detachments associated with drusen.

To understand the natural history of retinal pigment epithelial (RPE) detachments (PEDs) associated with drusen, we retrospectively reviewed 125 PEDs that had not undergone laser treatment over an average follow-up period of 28 months. We identified six types of RPE detachments: pseudo-vitelliform, confluent drusen, serous, vascular, and hemorrhagic lesions as well as PEDs associated with a retinal vascular abnormality. We correlated the type of detachment with visual acuity and anatomic outcome. The poorest results were obtained for PEDs associated with neovascularization (vascular, hemorrhagic, and retinal vascular abnormality types). Eyes presenting with pseudo-vitelliform lesions or confluent drusen had the best visual prognosis and anatomic results. Obvious subretinal new vessels developed in 16 (34%) of the serous PEDs over an average follow-up period of 25 months. Subretinal neovascularization was rare in the pseudo-vitelliform and confluent drusen groups. The proposed classification system may be useful in predicting the natural course of PEDs.

Adult↗