Biomedical subjects

Eva Stifter

Publications and source records attributed to Eva Stifter.

11 recordsLinked to original sources

PubMed2006

"Instant vision" compared with postoperative patching: clinical evaluation and patient satisfaction after bilateral cataract surgery.

PURPOSE: To compare two methods of postoperative dressing regimen: patching vs "instant vision" without patch. DESIGN: Prospective randomized clinical trial. METHODS: Sixty consecutive hospitalized, nonambulatory patients with cataract surgery under topical anesthesia on both eyes at different days were enrolled prospectively. In randomized order, one eye was patched for the first 24 hours postoperatively; the other eye was left open without patch to obtain "instant vision." Both eyes received the same anti-inflammatory and antibiotic drop therapy. RESULTS: Twenty-four hours postoperatively, no significant differences between patching and "instant vision" could be found for corrected and uncorrected visual acuity, corneal epithelial defects, conjunctival inflammation, anterior chamber flare, and intraocular pressure (P > .05). During the first 24 hours postoperatively, all tear film parameters were significantly worse in the "instant vision" eyes (P < .001), indicating a transient tear film instability. During the first four hours after cataract surgery, pain scores in the "instant vision" eyes were significantly higher than in the patched eyes (P < .001). Eight hours postoperatively and later, there were no significant differences in any pain scores (P > .05). After experiencing both methods, 27% of the patients subjectively rated the two methods as equivalent; 8% of the patients preferred "instant vision." Despite of the benefits of immediately improved orientation, 65% of the tested patients preferred patching to "instant vision" because of lower pain and foreign body sensations and psychologic arguments. CONCLUSIONS: The clinical examinations showed that both methods were equally safe for postoperative therapy. However, further efforts have to be made to increase the patients' comfort with "instant vision" in the first hours after cataract surgery.

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PubMed2006

Contrast acuity in cataracts of different morphology and association to self-reported visual function.

PURPOSE: To evaluate the relationship between contrast acuity at declining contrast levels and the type and density of lens opacity in cataract. METHODS: Contrast acuity at declining contrast levels was determined with the Holladay Contrast Acuity Test, in relation to the type and density of age-related cataract in 180 patients with bilateral cataract and 20 control subjects with normal macular function. Cataracts were graded according to the Lens Opacities Classification System (LOCS) III of nuclear color (NC), nuclear opalescence (NO), cortical (C), and posterior subcapsular (P) cataract. Best-corrected visual acuity and near contrast acuity were determined in randomized order monocularly in both eyes. Visual difficulties in everyday life were evaluated, using the VF-14 questionnaire and the Cataract Symptom Score. RESULTS: The contrast-dependent effect of cataract on contrast acuity was statistically significant (P < 0.001; two-way ANOVA). In the comparison of early, intermediate, and advanced nuclear, nuclear-cortical, and posterior subcapsular cataracts (PSCs), significantly reduced contrast acuity scores were found for the PSC groups (P < 0.001). Comparison of nuclear and nuclear-cortical cataracts showed the contrast acuity scores to be comparable at all contrast levels (P > 0.05). High correlation coefficients were found between the LOCS III P score and the contrast acuity measurements (r = 0.77-0.84; P < 0.001). In contrast, the correlation coefficients of the NO, NC, and C scores were considerably lower (r = 0.45-0.66; P < 0.001). High correlation coefficients were also found between the contrast acuity measurements and self-reported functional vision. CONCLUSIONS: The statistically significant, contrast-dependent effect of cataract on contrast acuity supports the clinical relevance of recording visual acuity at low contrast levels in patients with age-related cataract. Particularly, the severity of PSC has a strong influence on the impairment of contrast acuity. Contrast acuity corresponded closely to the self-reported visual difficulties in everyday life.

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PubMed2005

Differences in reading performance of patients with Drusen maculopathy and subretinal fibrosis after CNV.

PURPOSE: To evaluate differences in reading performance and contrast sensitivity on patients with drusen maculopathy and subretinal fibrosis after CNV (choroidal neovascularisation). METHODS: 136 patients (60 with drusen (D), 76 with fibrosis (F)) were studied. Patients were classified according to type of maculopathy and best-corrected visual acuity into groups D1 and F1 (LogMAR 0.2-0.4), groups D2 and F2 (LogMAR>0.4-0.7), and group F3 (LogMAR>0.7-1.3). Reading acuity (in LogRAD) and speed were examined with the Radner Reading charts and compared to the reading speed measured with the long paragraphs of the Zuercher Reading Test. Contrast sensitivity was measured with Pelli-Robson charts. RESULTS: The patients' distance visual acuity was comparable between the drusen and fibrotic CNV groups (D1 versus F1, D2 versus F2). The reading acuity of the corresponding groups D1 and F1 was also comparable, but F2 patients showed a statistically lower reading acuity than D2 patients (P=0.03). All reading speed measurements of the groups F1 and F2 were significantly worse than those of the corresponding groups D1 and D2 (P-values: 0.0005-0.02). The correlation of reading speed between the Radner and Zuercher texts was very high (r=0.73-0.94). The contrast sensitivity was significantly lower in all groups compared with group D1 (P<0.001), but comparable for groups F1, F2, and F3. CONCLUSIONS: Despite comparable results in distance visual acuity, patients with subretinal fibrosis after CNV had a greater reduction in reading ability than the patients with drusen. The distance visual acuity measurements alone, therefore, underestimate the real-life conditions and impact of AMD.

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PubMed2005

Influence of laser in situ keratomileusis and laser epithelial keratectomy on patients' reading performance.

PURPOSE: To evaluate the influence of laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK) on reading performance regarding reading acuity, reading speed based on print size, maximum reading speed, and critical print size. SETTING: Department of Ophthalmology, University of Vienna, Vienna, and Auge-und-Laser, Medicent Baden, Austria. METHODS: Fifty-two eyes of 34 patients (26 eyes per group) were studied. Best corrected LogMAR visual acuity (Early Treatment Diabetic Retinopathy Study charts), reading acuity, and reading speed were tested monocularly before LASIK or LASEK and 3 weeks after surgery. Reading acuity (LogRAD) and reading speed were determined with the standardized Radner reading charts. RESULTS: Preoperatively, the distance visual acuity and reading acuity were comparable between the LASIK and LASEK patients. Reading speed measurements also showed no statistical difference. Three weeks after refractive surgery, no statistically significant differences in the preoperative measures and between the 2 surgical procedures could be found in any tested parameters. The mean distance visual acuity was LogMAR -0.02 +/- 0.06 (SD) (LASIK) and LogMAR -0.05 +/- 0.07 (LASEK). The mean reading acuity was LogRAD 0.00 +/- 0.12 (97.7% of LogMAR) (LASIK) and LogRAD 0.04 +/- 0.16 (93.7% of LogMAR) (LASEK). The mean maximum reading speed was 235 +/- 35 words per minute (LASIK) and 240 +/- 37 words per minute (LASEK), and the mean critical print size was at LogRAD 0.48 +/- 0.19 (LASIK) and 0.49 +/- 0.17 (LASEK). CONCLUSIONS: In a standardized reading test setting, no significant effects of LASIK and LASEK on individual reading performance could be evaluated. This indicates that patients can expect to retain their normal visual function after refractive surgery with these 2 procedures under full light conditions.

Adult↗

PubMed2005

Discriminative power of reading tests to differentiate visual impairment caused by cataract and age-related macular degeneration.

PURPOSE: To determine whether preoperative reading tests can be used for differentiating visual impairments with regard to the diagnosis of cataract and age-related macular degeneration (ARMD). SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Reading performance of patients with nuclear cataract, posterior subcapsular cataract, and ARMD were evaluated with respect to reading acuity, maximum reading speed, and critical print size; normal-sighted participants were tested as controls. A multivariate discriminant analysis of the 4 groups (100 eyes of 100 participants) was performed to evaluate how many patients could be correctly diagnosed by significant differences in the tested reading parameters. Subsequently, the nuclear cataract and posterior subcapsular cataract patients were compared with cataract patients with coexisting ARMD. RESULTS: Distance visual acuity was comparable in the nuclear cataract, posterior subcapsular cataract, and ARMD groups (P>.05). Reading acuity was significantly reduced in posterior subcapsular cataract and ARMD patients compared with nuclear cataract patients and controls (P<.0001). No significant difference in maximum reading speed was found between the nuclear cataract patients and the controls (P = .07), whereas the maximum reading speed of the posterior subcapsular cataract and ARMD patients was significantly reduced (P<.0001). In the discriminant analysis, it was possible to assign the correct diagnosis to 72% of the nuclear cataract patients, 76% of the posterior subcapsular cataract patients, 72% of the ARMD patients, and 92% of the controls. Comparing the reading performance of nuclear cataract and posterior subcapsular cataract patients and cataract patients with coexisting ARMD showed that reading performance was significantly impaired in the comorbid patients (nuclear cataract and ARMD, P<.001; posterior subcapsular cataract and ARMD, P<.05). CONCLUSION: The high discriminant accuracy shows that this standardized reading test system is a valuable diagnostic tool for evaluating functional visual impairments when distance visual acuity alone cannot elucidate the origin of functional impairment. Considering the significant discrepancies in reading performance among patients with nuclear cataract, posterior subcapsular cataract, and ARMD, reading tests may relevantly improve the clinical evaluation of patients with visual loss, even of patients with ocular comorbidity.

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PubMed2005

Impairment of visual acuity and reading performance and the relationship with cataract type and density.

PURPOSE: To evaluate the association between the density of nuclear, cortical, and posterior subcapsular lens opacities and visual impairment in patients with cataract. METHODS: In 80 patients, visual acuity and reading performance were evaluated 1 day before and 4 weeks after cataract surgery. Cataracts were categorized and graded according to the Lens Opacities Classification System (LOCS) III of nuclear color (NC), nuclear opalescence (NO), cortical (C), and posterior subcapsular cataract (P). A multiple linear regression analysis and partial correlation coefficients were calculated. Data were also checked for significant pre- and postoperative differences in visual performance related to cataract grading. RESULTS: In the multiple linear regression analysis, significant associations were found between the improvement in visual acuity and reading performance after cataract surgery and the NC, NO, and P scores (P < 0.001); no significant association was found for the C score (P > 0.05). High partial correlation coefficients were found between the P score and the preoperative visual acuity (r = 0.6; P < 0.001), reading acuity (r = 0.74; P < 0.001), and maximum reading speed (MRS; r = -0.77; P < 0.001). Significant but lower partial correlation coefficients were found for the NO score. No significant partial correlation coefficients were found for the NC and C score. Significant pre- and postoperative differences in MRS were found in patients with P scores > or =3 or NO and NC scores > or =5, representing functionally relevant impairment. CONCLUSIONS: A strong association was found between visual impairment in patients with cataract and the severity of posterior subcapsular cataract (PSC) and nuclear opacity. Particularly in patients with PSC, deficits in reading performance significantly increased. The functionally relevant deficits in patients with P scores > or =3 or NO and NC scores > or =5, should be carefully considered for planning cataract surgery or visual rehabilitation.

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PubMed2004

Informed consent and decision making by cataract patients.

OBJECTIVES: To investigate decision making by patients on the day before cataract surgery and to evaluate to what extent the informed consent process influences the patients' decision regarding consent. METHODS: On the day before surgery, 70 patients (mean +/- SD age, 70.3 +/- 10.3 years) underwent a standardized informed consent procedure. They were also invited to answer 15 questions established in interdisciplinary cooperation among clinical psychologists, lawyers, and ophthalmologists. MAIN OUTCOME MEASURES: We assessed presurgical information and personal estimation of risks in cataract surgery; the patient-physician relationship regarding surgery-related decisions; and evaluations of the informed consent procedure and the patients' decision. RESULTS: Questionnaire answers indicated that 28 (40%) of the 70 participating patients arrived for surgery without any information; 16 (23%) believed that there were surgical procedures without risks; and 53 (76%) estimated that there were no risks for their cataract surgery. A physician-dominated decision for surgery was preferred by 31 patients (44%); 16 (26%) wanted to decide together with their ophthalmologist. Possible risks of a sight-threatening complication did not influence 54 patients' (77%) decisions, and 55 patients (78%) said the informed consent process did not influence their decision. The remaining 15 (22%) stated that the informed consent process positively confirmed their decision. CONCLUSIONS: Informed consent 1 day preoperatively does not seem to influence the decision for cataract surgery. Cognitive dissonance as part of a decision-making process makes changes in an already chosen option unlikely. The resulting limited decisive potential is very important for credibility in a trial and has to be considered in ophthalmologic surgery.

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PubMed2004

Reading performance depending on the type of cataract and its predictability on the visual outcome.

PURPOSE: To investigate the influence of various types of cataract on reading performance in a standardized reading test setting. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: The reading performance of 94 eyes with age-related cataract and normal macular function was evaluated with the Radner Reading Charts preoperatively and 4 weeks after cataract surgery. Distance visual acuity was tested with the ETDRS charts. Cataracts were graded using the Lens Opacities Classification System (LOCS) III, on which NO is nuclear opalescence and NC is nuclear color. RESULTS: Patients with pure nuclear cataracts (LOCS III: NO/NC 2.1-5) achieved a normally high MRS (99.84% +/- 7.65% of their postoperative MRS): preoperative MRS(1): 190.6 +/- 30.74 words per minute (wpm); postoperative MRS(2): 191.21 +/- 29.36 wpm. Patients with mixed nuclear-cortical cataracts (LOCS III: NO/NC 2.1-5; C>2) preoperatively achieved 96.96% +/- 5.6% of their postoperative MRS (MRS(1): 175.77 +/- 31.54 wpm; MRS(2): 181.34 +/- 30.56 wpm). In dense nuclear cataracts (LOCS III: NO/NC>5), the MRS was significantly reduced, achieving only 72.64 +/- 19.19% of the postoperative MRS (MRS(1): 133.06 +/- 39.43 wpm; MRS(2): 185.76 +/- 40.18 wpm). In posterior subcapsular cataracts, the preoperative MRS (134.1 +/- 33.72 wpm) was significantly lower than postoperatively (191.14 +/- 27.08 wpm). CONCLUSIONS: In contrast to dense nuclear cataracts and posterior subcapsular cataracts, the preoperative reading speed of patients with pure nuclear or nuclear-cortical cataracts was normal at large print sizes. The preoperative evaluation of reading acuity and speed with standardized reading tests can therefore be used to estimate the postoperative reading performance in the latter 2 types of cataract.

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PubMed2004

Functional vision with cataracts of different morphologies: comparative study.

PURPOSE: To evaluate the influence of cataract morphology on the functional vision of patients with age-related cataract and normal macular function and compare subjectively perceived functional impairments to distance visual acuity, reading acuity, and maximum reading speed between cataract types. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: Seventy-five patients awaiting first-eye cataract surgery were asked to characterize their visual difficulties in everyday life using a German version of the VF-14 questionnaire. Cataracts were categorized and graded using the Lens Opacities Classification System III. Monocular and binocular visual acuity and reading performance were determined in randomized order. RESULTS: There were significant differences in functional vision between nuclear cataracts and posterior subcapsular cataracts (PSC); the VF-14 score and the self-reported visual satisfaction were significantly lower in PSC patients (P<.05). Posterior subcapsular cataracts significantly increased self-reported impairment in distance and near vision, although the visual acuity was comparable to that in the other groups (P =.9). Significant differences in functional vision were also seen between PSC and nuclear-cortical cataracts (P<.05). No significant differences in functional vision were found between nuclear cataracts and nuclear-cortical cataracts (P>.05). CONCLUSIONS: The VF-14 questionnaire reliably evaluated functional differences caused by different cataract morphologies; these differences were underestimated when only visual acuity was measured. Patients with PSC had increased functional impairment, indicating that cataract surgical intervention is indicated at an earlier stage in these patients. The significant differences between the morphological types of cataract should be taken into consideration when the benefit of cataract surgery is to be measured on the basis of functional improvement.

Activities of Daily Living↗

PubMed2004

Tissue damage at anterior capsule edges after continuous curvilinear capsulorhexis, high-frequency capsulotomy, and erbium:YAG laser capsulotomy.

PURPOSE: To compare the effect of erbium:YAG laser photocapsulotomy (ELC), continuous curvilinear capsulorhexis (CCC), and high-frequency capsulotomy (HFC) on anterior capsule edges using light microscopy (LM) and transmission electron microscopy (TEM). SETTING: Department of Ophthalmology, Department of Histology and Embryology II, University of Vienna, Vienna, Austria. METHODS: Five anterior capsule membranes were obtained experimentally by ELC, which was performed with the Oertli MicroLaser photoemulsification tip in eyes from 5 human cadavers. Thirty anterior capsule membranes were obtained during cataract surgery by CCC (n = 15) or, in cases with poor or missing red fundus reflexes, by HFC (n = 15). Continuous curvilinear capsulorhexis was performed conventionally with a manual, bent, 27-gauge cannula, and HFC was performed according to Klöti. Membranes were processed and examined by LM and TEM according to standard procedures. RESULTS: The edges obtained by ELC showed mild signs of denaturation and mechanical disruption, tears, and micro-tears. Lens capsule edges obtained by CCC were smooth with no irregularities in any specimen; the edges were beveled anteriorly to posteriorly with no evidence of tearing. Edges produced by HFC were considerably wider; the surfaces showed distinct denaturation, preformed tears, and micro-tears. The edges were surrounded by a nonhomogeneous mass, which consisted mainly of denatured lens capsule material. CONCLUSIONS: Of the 3 techniques, CCC produced the mildest tissue damage. The histological damage at ELC edges was relatively mild and intermediate compared with that seen at CCC and HFC edges. These observations suggest that ELC is an appropriate option for anterior capsulotomy in cataract surgery.

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PubMed2003

Reliability of a standardized reading chart system: variance component analysis, test-retest and inter-chart reliability.

BACKGROUND: The purpose of this study was to analyze statistically the test-retest and inter-chart reliability of three standardized Radner Reading Charts with respect to reading acuity, maximum reading speed, critical print size and LogRAD/LogMAR ratio and to quantitatively identify the sources of variability. METHODS: At two testing sessions (3 to 4 weeks apart), 36 volunteers read monocularly all three Radner Reading Charts in randomized order (orthogonal Latin square design). The subjects were grouped according to their distance LogMAR visual acuity (group 1, 0.1 or better; group 2, 0.12-0.4; group 3, 0.42-0.8). Based on these 216 reading tests, crude correlations were calculated between the two testing sessions and between the three charts, and "variance component analyses" were performed for all variables. RESULTS: For all visual acuity groups and variables, the test-retest and the inter-chart reliability was high. The variance component analyses showed that the differences between individuals predominantly influenced the variance, whereas the effect of the test replication was low. The three charts caused minimal variability, indicating equality for clinical examinations. CONCLUSION: The standardized Radner Reading Charts provide clinically reliable and reproducible results for individuals with normal eyesight and for patients with visual impairment. These findings indicate that reading test systems, which consider the current international standards for visual acuity measurements (EN ISO 8596, NAS-NRC) and the psychophysical requirements for controlling optical item interactions, can provide reliable measures for clinical and scientific analyses of reading performance.

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