Angle-closure caused by an anterior segment membrane.
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Aged↗
Biomedical subjects
R Ritch
Publications and source records attributed to R Ritch.
Axial length and optic disc size in normal eyes.
AIM: To investigate the relationship between optic disc area and axial length in normal eyes of white and black people. METHODS: Consecutive eligible normal subjects were enrolled. Ocular biometry was obtained using A-scan ultrasonography, and reliable images of the optic disc were obtained using a confocal scanning laser ophthalmoscope. The relationship between optic disc area and axial length was assessed using univariate and multivariate models. RESULTS: 281 eyes of 281 subjects were enrolled. Black subjects (n = 157) had significantly larger discs (mean (SD) disc area, 2.12 (0.5) mm(2)) than white subjects (n = 124; 1.97 (0.6) mm(2); t test, p = 0.02). Optic disc area increased with axial length (Pearson's correlation coefficient, r = 0.13, p<0.035) for the entire study population. Multivariate regression models including race, disc area and axial length showed that a significant but weak linear relationship exists between axial length and disc area (partial correlation coefficient 0.14; p<0.024), and with race and disc area (partial correlation coefficient 0.19; p<0.017) when adjusted for the effects of other terms in the model. CONCLUSION: Increased disc area is associated with longer axial length measurements and African ancestry. This may have implications for pathophysiology and risk assessment of glaucoma.
Adolescent↗
Urrets-Zavalia syndrome as a complication of argon laser peripheral iridoplasty.
OBJECTIVE: To report on 8 patients who developed prolonged mydriasis after argon laser peripheral iridoplasty (ALPI). DESIGN: Retrospective case series. METHODS: A review of the charts of 8 patients with persistent occludable angles after laser iridotomy who developed mydriasis after undergoing ALPI. RESULTS: 12 eyes of 8 patients (mean age 50.2, standard deviation 6.9, range 40-61 years) developed persistent dilatation. 7 of 8 patients had plateau iris syndrome. Only one patient had a decrease in visual acuity. Intraocular pressure increased only in 1 eye and remained stable or decreased in the others. Of the 8 patients, 7 had blurred vision, 2 had photophobia, 4 had glare and 1 had discomfort. The pupillary response to pilocarpine instillation was minimal or absent. Mydriasis eventually resolved in all eyes without treatment. CONCLUSION: ALPI can be complicated by mydriasis unresponsive to pilocarpine. Mydriasis and accompanying symptoms resolved spontaneously within 1 year in most patients.
Adult↗
Structural and functional assessment of the macular region in patients with glaucoma.
PURPOSE: To investigate the correlation of a structural measure of the macular area (optical coherence tomography (OCT)) with two functional measures (10-2 Humphrey visual field (HVF) and multifocal visual evoked potential (mfVEP)) of macular function. METHODS: 55 eyes with open-angle glaucoma were enrolled. The 10-2 HVF was defined as abnormal if clusters of > or =3 points with p<5%, one of which had p<1%, were present. The mfVEP was abnormal if probability plots had > or =2 adjacent points with p<1%, or > or =3 adjacent points with p<5% and at least one of these points with p<1%. Two criteria were used for the macular OCT: (I) > or =2 sectors with p<5% or 1 sector with p<1% and (II) 1 sector with p<5%. RESULTS: 54 of the 55 eyes showed an abnormal 10-2 HVF and 50 had central mfVEP defects. The two OCT criteria resulted in sensitivities of 85% and 91%. When both functional tests showed a defect (in 49 eyes), the OCT was abnormal in 45. For the OCT the outer and inner inferior regions were the most likely to be abnormal, and both functional techniques were most abnormal in the superior hemifield. CONCLUSIONS: Good agreement exists between macular thickness and functional defects in patients with glaucoma. Study of the macular region may provide a quantitative measure for disease staging and monitoring.
Adult↗
Detection of glaucoma using operator-dependent versus operator-independent classification in the Heidelberg retinal tomograph-III.
OBJECTIVE: To compare the abilities of a new Glaucoma Probability Scoring (GPS) system and Moorfields regression analysis (MRA) to differentiate between glaucomatous and normal eyes using Heidelberg retinal tomograph (HRT)-III software and race-specific databases. METHODS: In this prospective study, one eye (refractive error < or =5 D) each of consecutive normal patients and those with glaucoma was enrolled. All patients underwent a full eye examination, standard achromatic perimetry (Swedish Interactive Threshold Algorithm-standard automated perimetry (SITA-SAP), program 24-2) and confocal scanning laser ophthalmoscopy (HRT-II) within 1 month. Normal patients had two normal visual fields in both eyes (pattern standard deviation (PSD) >5% and Glaucoma Hemifield Test within 97% normal limits) and a normal clinical examination. Glaucoma was defined on the basis of SITA-SAP visual field loss (PSD<5% or Glaucoma Hemifield Test outside normal limits) on two consecutive visual fields. HRT-II examinations were exported to the HRT-III software (V.3.0), which uses an enlarged race-specific database, consisting of 733 eyes of white people and 215 eyes of black people. Race-adjusted MRA for the most abnormal sector (operator-dependent contour line placement) was compared with the global race-adjusted GPS (operator independent). MRA sectors outside the 99.9% confidence interval limits (outside normal limits) and GPS > or =0.64 were considered abnormal. RESULTS: 136 normal patients (72 black and 64 white patients) and 84 patients with glaucoma (52 black and 32 white patients) were enrolled (mean age 50.4 (SD 14.4) years). The average visual field mean deviation was (-)0.4 (SD 1.1) db for the normal group and (-)7.3 (SD 6.7) db for the glaucoma group (p<0.001). Mean GPS values were 0.21 (SD 0.23) and 0.73 (SD 0.27) for normal and glaucomatous eyes, respectively (p<0.001). Sensitivity and specificity values were 77.1% and 90.3% for GPS, and 71.4% and 91.9% for MRA, respectively. CONCLUSIONS: In this cohort, GPS software sensitivity and specificity values are similar to those of MRA, which requires placement of an operator-dependent contour line. The development of software to detect glaucoma without a contour line is critical to improving the potential use of HRT as a tool for glaucoma detection and screening.
Black People↗
The effects of glaucoma on the latency of the multifocal visual evoked potential.
AIMS: To determine the effect of glaucomatous damage on the latency of the multifocal visual evoked potential (mfVEP). METHODS: Monocular mfVEPs were recorded from a glaucoma group (n = 50) defined by a glaucomatous disc and an abnormal visual field and a control group (n = 47). 25 patients were characterised as normal tension glaucoma (NTG) and 25 as high tension glaucoma (HTG). Monocular and interocular latency analyses of the more affected eye were obtained using custom software. RESULTS: On interocular analysis, both the HTG and NTG groups showed a statistically significant increase in mean mfVEP latency with average relative latencies and percentage of points with significant delays of 1.7 ms and 10.3% (HTG) and 1.3 ms and 8.2% (NTG) compared to -0.3 ms and 2.7% (controls). On monocular analysis, only the HTG group showed a significant increase in latency with measures of 5.7 ms and 14.6% (HTG) compared to 3.2 ms and 10.6% (NTG) and 2.1 ms and 9.6% (controls). Using the 95th percentile of a normative group as the cut off, the sensitivity ranged from 20% to 38% and the specificity from 87% to 100% with the interocular analysis providing the best discrimination, CONCLUSION: Although up to 40% of patients showed delays in the mfVEP latency, these delays were modest, on average a few milliseconds. These results differ markedly from those of a recent conventional VEP study, which reported 100% sensitivity, 100% specificity, and an average delay that exceeded 25 ms.
Adult↗
Intraocular pressure following phacoemulsification in patients with and without exfoliation syndrome: a 2 year prospective study.
AIM: To determine the long term intraocular pressure (IOP) response to phacoemulsification in patients with and without exfoliation syndrome (XFS). METHODS: Prospective, multicentre, cohort study with the following inclusion criteria: age over 50 years, open iridocorneal angle, and cataract. Two groups were enrolled: those with XFS and those without. The main outcome was mean IOP reduction 2 years after phacoemulsification cataract extraction (PCE). Univariate and multivariate analyses were performed. RESULTS: 183 patients were enrolled, 71 with and 112 without XFS. There were 29 patients with glaucoma in both groups. Mean baseline IOP was higher in XFS compared to control eyes (17.60 (SD 3.23) mm Hg v 16.08 (3.18) mm Hg, p = 0.002). Overall IOP reduction was significantly greater in the XFS group at the 2 year time point (-1.85 mm Hg v -0.62 mm Hg in the controls (p = 0.0037)). Multivariate analysis demonstrated that the IOP lowering effect in the XFS group may be related to irrigation volume at the time of surgery. In the subgroup analyses IOP lowering was significantly greater in the XFS and XFG patients than in controls without glaucoma, and POAG controls, respectively. The percentage of patients with a postoperative IOP spike was similar and relatively high in both XFS and control groups (34% v 25%; p = 0.54). CONCLUSION: IOP decreases more in patients with XFS following PCE compared to control eyes without XFS. This effect is more pronounced in glaucoma patients and persists for at least 2 years.
Aged↗
8-Isoprostaglandin F2a and ascorbic acid concentration in the aqueous humour of patients with exfoliation syndrome.
BACKGROUND/AIMS: The authors investigated the concentrations of 8-isoprostaglandin F(2a), a marker of oxidative stress in vivo, and ascorbic acid, a protectant against oxidative damage, in the aqueous humour of patients with exfoliation syndrome (XFS) and cataract and compared the results with those in age matched patients with cataract, but without XFS, to determine whether XFS is associated with increased oxidative stress. METHODS: Aqueous humour was aspirated at the beginning of phacoemulsification cataract surgery from 27 eyes of 27 cataract patients with XFS and 27 eyes of 27 age matched cataract patients without XFS. 8-Isoprostaglandin F(2a)concentration in the aqueous was determined with a commercial immunoassay; ascorbic acid concentration was measured with a microplate assay method. RESULTS: The mean concentration of 8-isoprostaglandin F(2a)in the aqueous from patients with XFS (2429 (SD 2940) pg/ml; range 400-10500 pg/ml) was significantly higher than that measured in the aqueous of age matched control patients (529.1 (226.8) pg/ml; range 325-1000 pg/ml); (p = 0.0028). Furthermore, mean ascorbic acid concentration in XFS patients (0.75 (0.39) mM; range 0.28-1.70 mM) was significantly lower than that found in control patients (1.19 (0.47) mM; range 0.53-2.4 mM); (p = 0.0005). There was a reverse correlation between 8-isoprostaglandin F(2a)and ascorbic acid concentration. CONCLUSION: 8-Isoprostaglandin F(2a)was significantly increased in the aqueous of patients with XFS, and ascorbic acid was decreased, providing evidence of a role for free radical induced oxidative damage in the pathobiology of XFS.
Antioxidants↗
Effect of a tight necktie on intraocular pressure.
AIM: To evaluate the effect of a tight necktie on intraocular pressure (IOP) measurement using Goldmann applanation tonometry. METHODS: 40 eyes of 20 normal subjects and 20 open angle glaucoma patients (all male) were enrolled. IOP was measured with an open shirt collar, 3 minutes after placing a tight necktie, and 3 minutes after loosening it. All measurements were made by the same examiner. RESULTS: Mean IOP in normal subjects increased by 2.6 (SD 3.9) mm Hg (p=0.008, paired t test; range -3 to +14 mm Hg) and in glaucoma patients by 1.0 (1.8) mm Hg (p=0.02, paired t test; range -2 to +4.5 mm Hg). In normal subjects, IOP in 12 eyes was increased by >/=2 mm Hg and in seven eyes by >/=4 mm Hg. In glaucoma patients, IOP in six eyes was increased by >/=2 mm Hg and in two eyes by >/=4 mm Hg. CONCLUSION: A tight necktie increases IOP in both normal subjects and glaucoma patients and could affect the diagnosis and management of glaucoma.
Adult↗
Patterns of retinal ganglion cell survival after brain-derived neurotrophic factor administration in hypertensive eyes of rats.
We investigated the effect of brain-derived neurotrophic factor (BDNF) on retinal ganglion cell (RGC) survival after intraocular pressure (IOP) elevation at various time intervals. In adult Wistar rats, RGCs were labeled with 5% Fluorogold. Animals with 1.8-2.5-fold increase in IOP after cauterization of three episcleral vessels, were divided into three BDNF groups and three vehicle control groups, each receiving one, two or three injections. The RGC survival percentage on RGCs of the first, second and third injections were 93.9% (n = 7), 91.3% (n = 7), 82.7% (n = 5), respectively in BDNF groups; 91.6% (n = 6), 84.1% (n = 6) and 73.5% (n = 5), respectively in vehicle controls. The second and third injections of BDNF showed statistically significant survival effects. These findings demonstrated that BDNF has partial neuroprotection on RGCs in whole retina and enhances RGC survival in moderately chronic hypertensive eyes.
Animals↗
Retinal pigment epithelial dysfunction in patients with pigment dispersion syndrome: implications for the theory of pathogenesis.
OBJECTIVE: To test the hypothesis that the retinal pigment epithelial/photoreceptor complex is affected in patients with pigment dispersion syndrome and/or in patients with pigmentary glaucoma. METHODS: Electro-oculograms were recorded from patients with pigment dispersion syndrome, pigmentary glaucoma, ocular hypertension, and primary open-angle glaucoma and from control subjects. Electro-oculograms were recorded during 15 minutes of dark adaptation followed by 15 minutes of light adaptation. For each subject, dark-trough amplitudes, dark-trough latencies, light-peak amplitudes, light-peak latencies, and ratios of the light-peak amplitude to the dark-trough amplitude (Arden ratios) were calculated. RESULTS: A 1-way analysis of variance of the Arden ratios indicated significant differences among the groups of subjects. Results of a post hoc Newman-Keuls test revealed that the mean Arden ratios of patients with pigment dispersion syndrome and patients with pigmentary glaucoma were significantly lower than the mean ratios of the controls, the patients with primary open-angle glaucoma, and those with ocular hypertension. CONCLUSIONS: The results provide support for the hypothesis that the integrity of the retinal pigment epithelial/photoreceptor complex is affected in patients with pigment dispersion syndrome and in those with pigmentary glaucoma. Congenital and/or structural abnormalities of the retinal pigment epithelial/photoreceptor complex should be considered when models of the etiology of pigment dispersion syndrome are proposed.
Adult↗
Attempted eyelid closure affects intraocular pressure measurement.
PURPOSE: To evaluate the effect of attempted eyelid closure on intraocular pressure measurement. METHODS: Normal subjects underwent intraocular pressure measurement in both eyes using Goldmann applanation tonometry and Tono-pen XL (Mentor, Inc, Norwell, Massachusetts) by the same examiner holding the eyelids open, both with and without the subject simultaneously attempting forced eyelid closure. Subjects were seated during all measurements and waited 5 minutes between measurements with each instrument; the order of measurement was randomized. RESULTS: Thirty eyes of 15 subjects (six men, nine women) were enrolled. Mean age was 30.5 +/- 5.2 years (range, 24 to 40 years). With Goldmann applanation tonometry, intraocular pressure increased in both eyes with attempted eyelid closure by a mean of 1.5 +/- 2.0 mm Hg (P =.0002, paired t test; range, -2 to 8 mm Hg). With the Tono-pen XL, intraocular pressure also increased in both eyes with attempted eyelid closure by a mean of 1.9 +/- 2.7 mm Hg (P =.0002, paired t test; range, -2 to 9 mm Hg). Tono-pen XL mean intraocular pressure values in both eyes (14.4 +/- 2.3 mm Hg) consistently overestimated those of Goldmann applanation tonometry (13.0 +/- 2.2 mm Hg) by a mean of 1.4 +/- 2.3 mm Hg. CONCLUSIONS: Attempted forced eyelid closure is a common and statistically significant source of error in routine outpatient measurement of intraocular pressure and could influence clinical management of glaucoma.
Adult↗
Vitreous opacities affect scanning laser polarimetry measurements.
PURPOSE: To assess the effect of vitreous opacities on retinal nerve fiber layer retardation measurements obtained during scanning laser polarimetry. METHODS: Scanning laser polarimetry was performed in two eyes of two patients with vitreous opacities. RESULTS: The presence of a vitreous opacity within the measurement ellipse during scanning caused a marked, localized increase in polarization in the area of the opacity. This falsely increased the value obtained for the mean retinal nerve fiber layer thickness. Retinal nerve fiber layer thickness values were reduced when the opacity was not incorporated into the measurement ellipse. CONCLUSION: Artifact introduced by the presence of vitreous opacities can affect scanning laser polarimetry measurement reliability.
Aged↗
Ultrasound biomicroscopic diagnosis of cyclitic membranes.
PURPOSE: To evaluate the utility of ultrasound biomicroscopy in imaging cyclitic membranes. METHODS: Patients with hypotony and suspected or known cyclitic membrane underwent ultrasound biomicroscopic examination. Histopathology of cyclitic membrane was correlated with ultrasound biomicroscopy in three cases. RESULTS: Six eyes of six patients were enrolled. Mean patient age was 62.2 +/- 18.4 (SD) years. The mean intraocular pressure in the affected eye was 4.3 +/- 3.4 mmHg. Three eyes were pseudophakic and three eyes were aphakic. All eyes had undergone two or more previous intraocular surgeries. Ultrasound biomicroscopy imaged the cyclitic membrane in all six eyes. Histopathology revealed fibroproliferative cyclitic membranes with associated inflammatory cells. CONCLUSION: Ultrasound biomicroscopy is useful in detecting the presence of those cyclitic membranes that may not be identified on clinical examination.
Adult↗
Glaucoma drainage tube kink after pars plana insertion.
PURPOSE: To describe focal obstruction of drainage tubes by kinking at the scleral entry site after pars plana insertion. METHODS: Case study. RESULTS: Three eyes of three patients underwent uncomplicated placement of a Baerveldt implant into the vitreous cavity at the time of pars plana vitrectomy. Intraocular pressure remained increased after the procedure without evidence of flow. Surgical exploration and modification of the tube placement resulted in immediate intraocular pressure reduction. Compression of the tube at the scleral entry site was confirmed intraoperatively in all eyes by ultrasound biomicroscopy. CONCLUSION: Kinking of the tube at its scleral entry site should be recognized as a possible cause of increased intraocular pressure without bleb formation after pars plana insertion of a glaucoma drainage implant.
Aqueous Humor↗
Ultrasound biomicroscopy before and after goniosynechialysis.
PURPOSE: To report the ultrasound biomicroscopic appearance of the anterior chamber angle before and after successful goniosynechialysis. METHODS: Interventional case report. Ultrasound biomicroscopy using a 50-MHz transducer was performed in the supine position preoperatively and postoperatively in a 76-year-old woman with angle-closure glaucoma. RESULTS: Ultrasound biomicroscopy of the anterior chamber angle demonstrated restoration of an open anterior chamber angle after goniosynechialysis. CONCLUSION: High-resolution imaging of the anterior segment to evaluate preoperative and postoperative anatomy may be useful in eyes undergoing goniosynechialysis.
Aged↗
Retinal nerve fiber layer thickness remains unchanged following laser-assisted in situ keratomileusis.
PURPOSE: To evaluate the effect of laser-assisted in situ keratomileusis (LASIK) on retinal nerve fiber layer (RNFL) thickness measurements obtained with scanning laser polarimetry (SLP), optical coherence tomography (OCT), and scanning laser tomography (SLT). DESIGN: Interventional case series. METHODS: Twenty eyes (20 patients) undergoing LASIK were enrolled in this prospective study. SLP, OCT, and SLT examinations were performed 1 week prior to and 1 week and 4 weeks after LASIK surgery. Intraocular pressure was normal at all preoperative and postoperative examinations. SLP, OCT, and SLT mean RNFL thickness values, and SLT RNFL cross sectional area, rim area, and rim volume before and after LASIK were compared by the Student paired t test. RESULTS: Mean patient age was 39.3 +/- 9.5 (SD) years (range, 28 to 62 years). Mean preoperative spherical equivalent refractive error was -3.9 +/- 1.9 diopters (D) (range, -1.4 to -8.00 D) and mean spherical equivalent refractive surgical correction was 3.6 +/- 1.9 D (range, 1.00 to 8.50 D). Mean RNFL thicknesses obtained by SLP were thinner 1 week and 4 weeks after LASIK (P < 0.01, for all comparisons, paired t test), whereas mean OCT RNFL thickness and SLT RNFL thickness, RNFL cross-section area, rim area, and rim volume measurements were unchanged 1 week and 4 weeks after LASIK (P > or = 0.05, for all comparisons, paired t test). CONCLUSIONS: LASIK does not affect RNFL thickness. Alterations in SLP RNFL thickness measurements are due to alterations in corneal architecture rather than an actual LASIK-induced RNFL injury.
Adult↗
Optical coherence tomography of Intacs.
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Corneal Stroma↗