Category: Peer-reviewed

Validity of Self-Report in Type 1 Diabetic Subjects for Laser Treatment of Retinopathy – Corrected Proof

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Purpose: This study sought to determine the validity of self-report of prior panretinal photocoagulation (PRP) and focal photocoagulation (FP) compared with fundus photography.Design: Prospective cohort study.Participants: One thousand three hundred sixty-three type 1 diabetic subjects from the Epidemiology of Diabetes Interventions and Complications (EDIC) study, a subset of the 1441 subjects originally enrolled in the multicenter Diabetes Control and Complications Trial.Methods: At each annual visit, subjects were asked by EDIC staff whether they had undergone PRP, FP, or both since the last completed annual clinic visit. Fundus photographs were collected from one quarter of the cohort each year and from the entire cohort at EDIC years 4 and 10. Photographs were graded for the presence and extent of PRP and FP. Seventeen years of subject reporting and photograph grading of PRP and FP were compared in EDIC subjects.Main Outcome Measures: The κ, sensitivity, specificity, and positive and negative predictive values were calculated for subject-reported PRP and FP. Factors influencing subject misreporting were investigated.Results: For subject reporting, 1244 (96%) of 1296 subjects with gradable photographs accurately reported whether they had a history of PRP in one or both eyes, and 1259 (97.5%) of 1291 with valid photographs correctly reported their history of FP. For PRP and FP, sensitivities were 90.4% and 74.0%, respectively; specificities were 96.0% and 98.8%, respectively; positive predictive values were 75.9% and 80.3%, respectively; negative predictive values were 98.9% and 98.4%, respectively; and κ values were 0.80 and 0.76, respectively. Risk factors associated with misreporting included prior laser for diabetic retinopathy and prior ocular surgery (each P<0.04).Conclusions: For subjects with type 1 diabetes, in the absence of a clinical examination or fundus photographs, subject self-report could be a reliable tool in a well-monitored study for assessing laser treatment type in diabetic retinopathy.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Prevalence of Dry Eye Disease and its Risk Factors in Visual Display Terminal Users: The Osaka Study – Corrected Proof

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Purpose: To investigate tear function and prevalence of dry eye disease (DED) in visual display terminal (VDT) users.Design: Cross-sectional study.Methods: Six hundred and seventy-two young and middle-aged Japanese office workers who used VDT completed questionnaires and underwent dry eye testing. We estimated the prevalence of DED using logistic regression analysis to examine associations between DED and possible risk factors. The ocular surface feature, prevalence of DED, and risk factors were evaluated.Results: Of the 672 workers, 561 (83.5%, mean age: 43.3 ± 9.1 years) completed the questionnaire. The percentage of women with a composite outcome of definite DED or probable DED was 76.5%, which was higher than that among men (60.2%; odds ratio [OR] = 2.00; 95% confidence interval [CI], 1.29-3.10, P = .002). Workers over 30 years of age had a higher risk of DED (OR = 2.22; 95% CI, 1.06-4.66), as did workers using a VDT >8 hours per day (OR = 1.94; 95% CI, 1.22-3.09). Average Schirmer value was 18.7 ± 11.7 mm and tear break-up time (TBUT) was 4.0 ± 2.5 seconds (78.6% of study participants had TBUT ≤5 seconds).Conclusions: DED is prevalent among young to middle-aged Japanese VDT users. Ophthalmic findings revealed short TBUT and corneal staining accompanied by normal Schirmer test values. Increased risk for DED was noted for women aged over 30 years and prolonged VDT use. Measures to modify the adverse impact of VDT use on the ocular surface may provide a positive impact on public health and quality of life for office workers using VDTs.

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Measurement of the Optic Disc Vertical Tilt Angle With Spectral-Domain Optical Coherence Tomography and Influencing Factors – Corrected Proof

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Purpose: To report a novel method for measuring the vertical tilt angle of the optic nerve (ON) head and to investigate the associated factors.Design: Cross-sectional diagnostic study.Methods: One hundred and twelve normal, glaucomatous, and glaucoma suspect eyes (99 patients) were enrolled in this study. Subjects underwent a full eye examination, biometry, and spectral-domain optical coherence tomography (SDOCT). The vertical tilt angle was measured on high-resolution cross-sectional SDOCT images passing through the ON head and foveal centers using the inner edges of the Bruch membrane opening as the reference plane. The correlation between the vertical tilt angle with the ovality index and the potential associated factors was estimated with univariate and multivariate linear regression analyses.Results: The median (interquartile range, [IQR]) axial length and visual field mean deviation were 24.5 (23.8-25.3) mm and −0.9 (−2.76 to 0.26) dB. The median (IQR) tilt angle was 3.5 (1.2-11.2) degrees. There was a moderate correlation between the ovality index and tilt angle (Spearman ρ = 0.351; P < .001). In univariate analyses, axial length, spherical equivalent, and mean deviation were correlated with the tilt angle (P = .002, P = .011, and P = .013, respectively). Axial length, mean deviation, and their interaction showed a statistically significant correlation with the tilt angle in multivariate analyses (P = .044 for axial length, P = .039 for mean deviation, and P = .028 for their interaction).Conclusions: We describe a new method for measuring the ON head vertical tilt angle with high-resolution SDOCT imaging. The ovality index demonstrated only a moderate correlation with the tilt angle measurements and hence is not a good proxy measure for the vertical ON head tilt angle. Axial length and visual field mean deviation are the main factors associated with the ON head vertical tilt angle. The underlying basis for the relationship of vertical tilt angle and glaucoma severity should be further explored.

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Retinal ganglion cells: Energetics, compartmentation, axonal transport, cytoskeletons and vulnerability

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Publication date: Available online 23 July 2013
Source:Progress in Retinal and Eye Research
Author(s): Dao-Yi Yu , Stephen J. Cringle , Chandrakumar Balaratnasingam , William H. Morgan , Paula K. Yu , Er-Ning Su
Retinal ganglion cells (RGCs) are specialized projection neurons that relay an immense amount of visual information from the retina to the brain. RGC signal inputs are collected by dendrites and output is distributed from the cell body via very thin (0.5 to 1 μm) and long (∼50 mm) axons. The RGC cell body is larger than other retinal neurons, but is still only a very small fraction (one ten thousandths) of the length and total surface area of the axon.The total distance traversed by RGCs extends from the retina, starting from synapses with bipolar and amacrine cells, to the brain, to synapses with neurons in the lateral geniculate nucleus.This review will focus on the energy demands of RGCs and the relevant tissues that surround them. RGC survival and function unexceptionally depends upon free energy, predominantly adenosine triphosphate (ATP). RGC energy metabolism is vastly different when compared to that of the photoreceptors.Each subcellular component of the RGC is remarkably different in terms of structure, function and extracellular environment. The energy demands and distribution of each component are also distinct as evidenced by the uneven distribution of mitochondria and ATP within the RGC – signifying the presence of intracellular energy gradients. In this review we will describe RGCs as having four subcellular components, (1) Dendrites, (2) Cell body, (3) Non-myelinated axon, including intraocular and optic nerve head portions, and (4) Myelinated axon, including the intra-orbital and intracranial portions.We will also describe how RGCs integrate information from each subcellular component in order achieve intracellular homeostatic stability as well as respond to perturbations in the extracellular environment. The possible cellular mechanisms such as axonal transport and axonal cytoskeleton proteins that are involved in maintaining RGC energy homeostasis during normal and disease conditions will also be discussed in depth. The emphasis of this review will be on energetic mechanisms within RGC components that have the most relevance to clinical ophthalmology.

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Age- and Hypertension-Dependent Changes in Retinal Vessel Diameter and Wall Thickness: An Optical Coherence Tomography Study – Corrected Proof

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Purpose: To validate and evaluate the reliability of retinal vessel diameter measurements by optical coherence tomography (OCT). The effects of age and hypertension on vessel diameter were also examined.Design: Prospective, cross-sectional study.Methods: Two hundred thirty-eight eyes (238 subjects) with no ocular disease were included. Hypertension was present in 106 subjects and absent in 132 subjects. Spectralis HRA+OCT was used to scan a circular region around the optic disc. Outer and inner diameters of the 4 largest retinal arteries and veins were measured using OCT vascular wall reflections, and vessel wall thickness was calculated.Results: Intervisit, interexaminer, and interevaluator intraclass correlation coefficients of randomly selected vessel measurements were all greater than 0.90. Mean inner arterial and venous diameters were 87.8 ± 9.4 μm and 113.7 ± 12.5 μm, respectively. The OCT-measured mean inner arterial and venous diameters were significantly correlated to fundus photography caliber measurements (P = .005 and P = .001, respectively). Arterial and venous wall thicknesses were 17.4 ± 2.4 μm and 13.7 ± 2.1 μm, respectively, both of which were highly correlated with subject age (arterial: r = 0.612, P < .001, venous: r = 0.455, P < .001). Additionally, both mean arterial and venous wall thicknesses were significantly greater in subjects with hypertension than in age-matched subjects without hypertension (P = .020 and P = .015, respectively).Conclusions: Retinal vessel diameter measurements obtained with OCT were highly reproducible and vessel wall thicknesses, calculated using outer and inner diameter measurements, were significantly thickened by both aging and systemic hypertension.

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Comparison of the Effect of Ranibizumab and Verteporfin for Polypoidal Choroidal Vasculopathy: 12-Month LAPTOP Study Results – Corrected Proof

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Purpose: To compare the effect of photodynamic therapy (PDT) and intravitreal ranibizumab in patients with polypoidal choroidal vasculopathy (PCV).Design: Randomized clinical trial.Methods: setting: Multicenter. study population: Total of 93 patients with treatment-naïve PCV. intervention: Patients were randomized to 2 arms. Patients in the PDT arm underwent a single session of PDT with verteporfin, and patients in the ranibizumab arm received 3 monthly ranibizumab injections at baseline. Additional treatment was performed as needed in each arm. main outcome measures: Primary outcome measurement was the proportion of patients gaining or losing more than 0.2 logarithm of minimal angle of resolution (logMAR) units from baseline. Mean change of logMAR and central retinal thickness (CRT) were also evaluated.Results: In the PDT arm (n = 47), 17.0% achieved visual acuity gain, 55.3% had no change, and 27.7% experienced visual acuity loss. The results were 30.4%, 60.9%, and 8.7%, respectively, in the ranibizumab arm (n = 46), significantly better than the PDT arm (P = .039). In the PDT arm, mean CRT improved (366.8 ± 113.6 μm to 289.1 ± 202.3 μm, P < .001), but logMAR was unchanged (0.57 ± 0.31 to 0.62 ± 0.40). The ranibizumab arm demonstrated improvement in both CRT (418.9 ± 168.6 μm to 311.2 ± 146.9 μm, P < .001) and logMAR (0.48 ± 0.27 to 0.39 ± 0.26, P = .003). Mean change of logMAR was also greater in the ranibizumab arm (P = .011).Conclusion: Intravitreal injection of ranibizumab is more effective than PDT for treatment-naïve PCV.

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Intraocular Pressure after Implantation of the Visian Implantable Collamer Lens With CentraFLOW Without Iridotomy – Corrected Proof

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Purpose: To compare the intraocular pressure (IOP) values during a 3-month period after implantation of the new Visian Implantable Collamer Lens (ICL; STAAR Surgical Company, Nidau, Switzerland) V4c design with CentraFLOW technology without iridotomy using a standard procedure followed by implantation of the conventional ICL V4b model.Design: Retrospective cohort study.Methods: This study included 17 eyes implanted with the ICL V4b model and 18 eyes implanted with the ICL V4c model. The mean preoperative spherical equivalent refractions were −7.48 ± 5.00 diopters and −8.66 ± 4.2 diopters, respectively. We compared the best-corrected distance visual acuity before surgery with the uncorrected distance visual acuity after surgery. The intraocular pressure (IOP) was measured 1 week, 1 month, and 3 months after surgery. The central vault at 3 months was measured using optical coherence tomography.Results: Three months after surgery, the mean uncorrected distance visual acuities were −0.09 ± 0.12 logarithm of the minimal angle of resolution units with the V4b and −0.07 ± 0.11 logarithm of the minimal angle of resolution units with the V4c. The mean distances between the ICL and the anterior crystalline lens surface were 557 ± 224 μm and 528 ± 268 μm for the V4b and V4c, respectively (P = .73). After 1 week and 1 month, the mean IOPs were 13.7 and 13.3 mm Hg and 14.7 and 15.1 mm Hg, respectively. There were no significant differences in IOP within or between groups during the follow-up period (P > .05, for all comparisons).Conclusions: The new ICL with the CentraFLOW design seems to provide similar results as its predecessors for the correction of moderate to high myopia and maintenance of safe IOP levels without iridotomy.

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