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Öğe Automated computer system grading of diabetic retinopathy from fundus photographs(2009) Ünver, Y.B.; Yavuz, Gülderen Aktan; Sinclair, Stephen H.Purpose: To evaluate the efficacy of computer algorithms in the detection and grading of retinopathy derived from screening of diabetic photographs. Methods: Screening fundus photographs (5 per eye) taken with a mydriatic camera in a general ophthalmology clinic for 52 sequential diabetic patients were graded by a general ophthalmologist and a retina specialist and compared with computer grading of digitized images acquired from color slides. Results: Among the 104 eyes, 64 (61.5%) had no retinopathy lesions (Grade 10), 6 (5.8%) eyes had only 1 or 2 microaneurysms, 21 (20.2%) eyes had more than 2 microaneurysms but no other lesions (grade 21), and 18 (17.3%) had additional lesions (grade 21+). Among the ophthalmologists, there was exact agreement in the grading of 76 eyes; in 21 eyes grading by each was within 1 grade level, and in 7 the grades differed by 2 grade levels. Computer algorithm grading agreed with the ophthalmologists' grade in 51 (50%) eyes; in 24 (23%) eyes the computer under-graded by one grade level, and by 2 grades in 2 eyes. In 22 (21%) eyes, computer grading was greater by one grade level than the ophthalmologists' grading and in 5 (5%) eyes the algorithms overgraded by 2 grades. Conclusions: Computer algorithms were able to detect and grade retinopathy from fundus photographs taken of a set of sequentially screened diabetics with consistency similar to the agreement in grading between a general ophthalmologist and a retina specialist.Öğe Central field perimetry of discriminated targets: I. Results for normal individuals using high-contrast targets(Nature Publishing Group, 2009) Yavuz, Gülderen Aktan; Ünver, Y.B.; Bekiroğlu, N.; Presti, Peter; Sinclair, Stephen H.Purpose A new perimetry method is described to evaluate central vision under multiple hue, illumination, and contrast conditions; results are described for normal individuals using high-contrast targets. Methods For 70 normal eyes of individuals with varying age, the ETDRS chart acuity was determined as well as discriminated target perimetry using high-contrast targets presented for 250 ms at locations up to 10 degrees eccentricity. Retesting was performed to evaluate for learning and repeatability for the thresholded acuity at each eccentricity. Results The ETDRS acuity averaged 1.15 +/- 0.37 arc min minimum angle of resolution (MAR) with best correction (20/23 equivalence). At fixation, the thresholded acuity for high-contrast targets paralleled the ETDRS acuity and averaged 1.75 +/- 0.85 arc min MAR (20/35 equivalence), and declined with increasing eccentricity in a linear fashion to 5.81 +/- 3.97 arc min (20/116 equivalent) at 10 degrees eccentricity. Linear regression showed Vmar = 1.74 vertical bar 0.330 * eccentricity in degrees (R-2 = 0.966, P < 0.0001). Testing time required similar to 8-10 min per eye. Repeated testing showed only minimal learning experience at the most peripheral locations. The test-retest 95% confidence limits of difference measured 1.12 arc mins MAR at fixation (64% of the mean) and remained approximately the same proportion to the mean thresholded acuity outwards to 10 degrees eccentricity. Conclusion The methodology seems rapid and reliable for measuring discriminatory visual function of optotype targets throughout the central 20 degrees diameter visual field. Eye (2009) 23, 2082-2089; doi:10.1038/eye.2009.177; published online 17 July 2009Öğe Entoptic Phenomenon Following Pars Plana Vitrectomy Caused by Retained Preretinal Gel(Slack Inc, 2009) Yavuz, Gülderen Aktan; Ünver, Yaprak Banu; Sinclair, Stephen H.A patient who underwent pars plana vitrectomy for vitreous floaters is described. At the time of surgery, the posterior hyalold was avulsed and stripped from the posterior retinal surface. Postoperatively, the patient described filamentous and "sea-fan" entoptic phenomena scattered throughout the periaxial vision that were in focus, attached, and "waving" with movement that was counter to the direction of gaze pursuit and demonstrated after movement. The authors believe these structures represent vitreous gel retained at the retinal surface, even though the structures could not be demonstrated by optical coherence tomography or indocyanine green staining at later vitrectomy surgery. This case should raise caution when considering vitrectomy surgery that requires posterior hyalold stripping in patients with good vision. [Ophthalmic Surg Lasers Imaging 2009;40:188-191.]Öğe Interactive, computer-based, self-reported, visual function questionnaire: the PalmPilot-VFQ(Nature Publishing Group, 2009) Ünver, Y.B.; Yavuz, Gülderen Aktan; Sinclair, Stephen H.Purpose To evaluate the testing performance, reliability, and validity of a self-administered visual function questionnaire designed for a Palm Pilot in comparison with the interviewer-administered-National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25) (interviewer-NEI-VFQ-25) and self-administered-NEI-VFQ-25 (self-NEI-VFQ-25). Method The interviewer-NEI-VFQ-25 was administered to 135 sequential patients who visited a retina clinic, followed on separate days by the Palm Pilot-Visual Function Questionnaire (PalmPilot-VFQ) and self-NEI-VFQ-25. Rasch analysis of ordinal difficulty ratings for the PalmPilot-VFQ was used to estimate interval measures of perceived visual ability. Reliability was determined by calculating Cronbach's alpha and test-retest intraclass correlation coefficients (ICCs). Concurrent validity was determined by calculating correlations of the PalmPilot-VFQ score with that of a general vision question. For evaluating convergent validity, the PalmPilot-VFQ was compared with the interviewer-NEI-VFQ-25, habitual-correction visual acuity (HCVA), and with two visual analogue scale (VAS) questions. Performance time and testability were compared among the three questionnaires. Results Rasch analysis eliminated two items in the PalmPilot-VFQ due to poor-fit statistics. The final items showed internal consistency (Cronbach's alpha=0.89) and test-retest reliability (ICC=0.79), as well as an excellent separation index (3.23 and 4.01) for item parameters with significant concurrent correlation (P<0.0001). On evaluating convergent validity, the PalmPilot-VFQ showed strong correlations with interviewer-NEI-VFQ-25, with the HCVA of the better-seeing eye, and with the VAS questions (P=0.0001). Ninety percent of the 135 patients (HCVA >20/200 in the better-seeing eye) could perform the PalmPilot-VFQ with their habitual correction or high-plus spectacles, but in significantly less time than either interviewer-NEI-VFQ-25 or self-NEI-VFQ-25 (P<0.0001). Conclusion The PalmPilot-VFQ seems to be a reliable, valid, interactive, computer-based, self-administered questionnaire that can be used routinely by physicians to evaluate functional vision disability in populations with a high prevalence of macular disease. Eye (2009) 23, 1572-1581; doi:10.1038/eye.2009.101; published online 29 May 2009Öğe Relationships between clinical measures of visual function and anatomic changes associated with bevacizumab treatment for choroidal neovascularization in age-related macular degeneration(Nature Publishing Group, 2009) Ünver, Y.B.; Yavuz, Gülderen Aktan; Bekiroğlu, N.; Presti, Peter; Li, Weiye; Sinclair, Stephen H.Purpose This pilot study was undertaken to examine the relationships between clinical measures of visual function and anatomic changes occurring in the eyes treated with bevacizumab for choroidal neovascularization (CNV) due to age-related macular degeneration (AMD). Methods A retrospective review was conducted for 50 eyes that had been treated with at least three injections of bevicizumab for CNV due to AMD, and followed for at least 6 months. Vision outcomes included best-corrected ETDRS chart acuity, scored by best-line read (ETDRS line) and by total letters read (ETDRS letter), and two measures obtained from central acuity perimetry with 98% Michelson contrast targets, the best acuity within 6 degrees of fixation (BA6 degrees), and global macular acuity (GMA), representing a weighted average of the acuities thresholded at all intercepts within a 10 degrees radius of fixation. Assessment of anatomic outcomes included fibrosis, atrophy, and subretinal hemorrhage grading on fundus photography, CNV size, pigment epithelial detachment (PED) size and grading of CNV leakage on fluorescein angiography, and central retinal PED, and subretinal fluid (SRF) thickness on optical coherence tomography. Results Logistic regression analysis showed an association between the vision outcomes of EDTRS letter and BA6 degrees with the change in SRF thickness (R-2: 0.47 and 0.35, respectively). The outcome of the vision measurement of GMA was associated with the change in SRF thickness, in CNV thickness, and in CNV fibrosis grade (R-2: 0.34). No association was noted between the outcomes of ETDRS line with the change in any anatomic outcomes. Conclusion Acuity perimetry outcomes in this study seemed to offer improved understanding of the relationship between the vision outcomes and the measured anatomic changes. It seemed that neither ocular coherence tomography nor fluorescein angiography alone offered sufficient morphologic markers for prediction of functional outcomes.
