Category: Peer-reviewed

The Cost of Glaucoma Care Provided to Medicare Beneficiaries from 2002 to 2009 – Corrected Proof

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Purpose: To estimate payments for glaucoma care among Medicare beneficiaries from 2002 to 2009.Design: Database study.Participants: Data from a 5% random sample of Medicare billing information from 2002 to 2009.Methods: Medicare beneficiaries, aged 65 years or older, with both Parts A and B fee-for-service (FFS) enrollment comprised the annual denominator. For each year, we included those with a defined glaucoma diagnostic code linked to a glaucoma visit, diagnostic test, or laser/surgical procedure. Open-angle, angle-closure, and other glaucoma were categorized separately. Claims were classified into glaucoma care, other eye care, and other medical care.Main Outcome Measures: Cost of glaucoma care in the Medicare Fee-for-Service Population.Results: In 2009, total glaucoma payments by Medicare were $37.4 million for this subset, for an overall estimated cost of $748 million, or 0.4% of an estimated cost of $192 billion for all Medicare FFS payments. Office visits comprised approximately one half, diagnostic testing was approximately one-third, and surgical and laser procedures were approximately 10% of glaucoma-related costs. Coded open-angle glaucoma (OAG) and OAG suspects accounted for 87.5% of glaucoma costs, whereas cost per person was highest in “other glaucoma.” In 2009, <3% of patients with OAG underwent incisional surgery and approximately 5% had laser trabeculoplasty. Laser iridotomy was the highest cost category among patients with angle-closure glaucoma, whereas office visits was the highest cost category among the “other glaucoma” group. The total cost of nonglaucoma eye care for patients with glaucoma was 67% higher than their glaucoma care costs; these were chiefly costs for cataract surgery and treatment of retinal diseases. From 2002 to 2009, FFS glaucoma care costs calculated in 2009 dollars were stable and cost per person per year in 2009 dollars decreased from $242 to $228 (P = 0.01 by test for linear trend).Conclusions: Annual glaucoma care costs per person decreased in constant dollars from 2002 to 2009. Cataract and retinal eye care for patients with glaucoma substantially exceeded the cost of their glaucoma care each year. Visit payments represented the largest category of costs.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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The Clinical Effect of Homozygous ABCA4 Alleles in 18 Patients – Corrected Proof

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Purpose: To describe the phenotypic presentation of a cohort of individuals with homozygous disease-associated ABCA4 variants.Design: Retrospective case series.Participants: Eighteen affected individuals from 13 families ascertained from a total cohort of 214 families with ABCA4-related retinal disease presenting to a single center.Methods: A detailed history was obtained, and color fundus photography, autofluorescence (AF) imaging, optical coherence tomography (OCT), and electrophysiologic assessment were performed. Phenotypes based on ophthalmoscopy, AF, and electrophysiology were assigned using previously reported characteristics. ABCA4 mutation detection was performed using the ABCR400 microarray (Asper Biotech, Tartu, Estonia) and high-throughput DNA sequencing, with direct sequencing used to assess segregation.Main Outcome Measures: Detailed clinical, electrophysiologic, and molecular genetic findings.Results: Eleven disease-associated homozygous ABCA4 alleles were identified, including 1 frame shift, 2 stops, 1 intronic variant causing splice-site alteration, 2 complex missense variants, and 5 missense variants: p.Glu905fsX916, p.Arg1300X, p.Gln2220X, c.4253+4 C>T, p.Leu541Pro and p.Ala1038Val (homozygosity for complex allele), p.Val931Met and p.Arg1705Gln (complex allele), p.Arg212Cys, p.Cys1488Arg, p.Arg1640Trp, p.Gly1961Glu, and p.Leu2027Phe. Eight of these 11 homozygous alleles have not been reported previously. Six of 7 patients with homozygous null alleles had early-onset (<10 years) disease, with all 7 having a severe phenotype. Two patients with homozygous missense variants (p.Leu541Pro and p.Ala1038Val [complex], and p.Arg1640Trp) presented with a severe phenotype. Three patients with homozygous p.Gly1961Glu had adult-onset disease and a mild phenotype. One patient with homozygous p.Leu2027Phe showed a spared fovea and preserved visual acuity.Conclusions: The phenotypes represented in patients identified as homozygous for presumed disease-associated ABCA4 variants gives insight into the effect of individual alleles. Null alleles have severe functional effects, and certain missense variants are similar to nulls, suggesting complete abrogation of protein function. The common alleles identified, p.Gly1961Glu and p. Leu2027Phe, both have a mild structural and functional effect on the adult retina; the latter is associated with relatively retained photoreceptor architecture and function at the fovea.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Analysis of Tear Cytokines and Clinical Correlations in Sjögren Syndrome Dry Eye Patients and Non–Sjögren Syndrome Dry Eye Patients – Corrected Proof

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Purpose: To compare concentrations of tear cytokines in 3 groups composed of Sjögren syndrome (SS) dry eye, non–Sjögren syndrome (non-SS) dry eye, and normal subjects. Correlations between ocular surface parameters and tear cytokines were also investigated.Design: Prospective cross-sectional study.Methods: SS dry eye patients (n = 24; 40 eyes) were diagnosed with primary SS according to the criteria set by the American-European Consensus Group. Non-SS dry eye patients (n = 25; 40 eyes) and normal subjects (n = 21; 35 eyes) were also enrolled. Tear concentrations of interleukin (IL)-17, IL-6, IL-10, IL-4, IL-2, interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α) were measured by a multiplex immunobead assay. Ocular Surface Disease Index (OSDI), tear film breakup time (TBUT), Schirmer I test, and fluorescein staining scores were obtained from dry eye patients.Results: All cytokine levels except for IL-2 were highest in the SS group, followed by non-SS dry eye group and control subjects. Concentrations of IL-17, TNF-α, and IL-6 were significantly different among the 3 groups (IL-17: SS > control P < .001, non-SS > control P = .042, SS > non-SS P < .001; TNF-α: SS > control P = .006, non-SS > control P = .034, SS > non-SS P = .029; IL-6: SS > control P = .002, non-SS > control P = .032, SS > non-SS P = .002). IL-17 was significantly correlated with TBUT (R = −0.22, P = .012) and Schirmer I test (R = −0.36, P = .027) scores in the SS group. IL-6 was significantly correlated only with TBUT (R = −0.38, P = .02) in the non-SS group.Conclusions: Differences in tear cytokine levels and correlation patterns between SS dry eye and non-SS dry eye patients suggest the involvement of different inflammatory processes as causes of dry eye syndrome.

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Estimated Retinal Ganglion Cell Counts in Glaucomatous Eyes with Localized Retinal Nerve Fiber Layer Defects – Corrected Proof

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Purpose: To estimate retinal ganglion cell (RGC) losses associated with visible glaucomatous localized retinal nerve fiber layer (RNFL) defects.Design: Observational cross-sectional study.Methods: A multicenter study of 198 normal eyes (138 subjects) and 66 glaucomatous eyes (55 subjects) recruited from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. All eyes underwent standard automated perimetry (SAP), spectral-domain optical coherence tomography, and fundus stereophotography within 6 months. Glaucomatous eyes were included if localized RNFL defects were detected by masked grading of stereophotographs. The number of RGCs in each sector of a structure-function map was estimated using a previously published model combining RGC estimates from SAP and spectral-domain optical coherence tomography. The estimated percentage loss of RGCs (combined structure-function index) was calculated.Results: In glaucomatous eyes, there were 136 sectors with visible RNFL defects and 524 sectors without visible RNFL defects. The most common sectors with visible RNFL defects were inferior and inferotemporal sectors, followed by superior and supertemporal sectors. Eyes with visible RNFL defects had a mean estimated RGC count of 657 172 cells versus 968 883 cells in healthy eyes (P < .001). The average combined structure-function index in sectors with a visible RNFL defect (59 ± 21%) was significantly higher than in sectors without a visible RNFL defect in glaucomatous eyes (15 ± 29%; P < .001) and higher than in healthy eyes (1 ± 13%; P < .001).Conclusions: Although visible localized RNFL defects often are considered an early sign of glaucoma, this study indicates that they are likely to be associated with large neuronal losses.

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Meibomian Gland Dysfunction and Hypercholesterolemia – Corrected Proof

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Objective: Hypercholesterolemia (total cholesterol ≥200 mg/dl) is a significant risk factor for ischemic heart, cerebrovascular, and peripheral vascular disease. Increased cholesterol in the glandular secretion has been postulated to be necessary for the development of meibomian gland dysfunction (MGD), a common form of chronic blepharitis. The purpose of this study was to investigate a possible correlation between MGD and hypercholesterolemia in young and middle-aged patients (aged 18–54 years).Design: Observational, case-control pilot study.Participants and Controls: Sixty symptomatic patients with MGD with no history of hypercholesterolemia and 63 controls without MGD and with no history of hypercholesterolemia, accrued from January 2011 to June 2012.Interventions: Body mass index (BMI), fasting blood triglycerides, total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), glucose, and creatinine were measured. Z test or Student t test was used, when appropriate, to calculate differences between groups. Stepwise logistic regression models were used to calculate the estimates of odds ratios (ORs), considering MGD as the dependent variable and including sex, age, BMI, triglycerides, total cholesterol, LDL, HDL, glucose, and creatinine as covariates.Main Outcome Measures: Fasting blood levels of total cholesterol, LDL, and HDL (milligrams/deciliter).Results: Hypercholesterolemia was found in 35 cases (58.3%) and 4 controls (6.3%), a statistically significant difference (P < 0.0001). Mean total cholesterol, LDL, and HDL were 210.8±4.4, 127.6±3.9, and 61.6±1.8 mg/dl, respectively, in cases and 162.9±3.1, 94.2±2.6, and 52.5±1.3 mg/dl, respectively, in controls. All differences were statistically significant (P ≤ 0.0001). Stepwise logistic regression analysis, including sex, BMI, triglycerides, total cholesterol, and glucose as covariates, revealed that MGD was significantly associated with higher blood levels of total cholesterol (OR, 1.07; 95% confidence interval [CI], 1.04–1.09; P < 0.001). Likewise, MGD was found to be significantly associated with increased blood levels of LDL (OR, 1.07; 95% CI, 1.04–1.09; P < 0.001) and HDL (OR, 1.11; 95% CI, 1.06–1.17; P < 0.001).Conclusions: The results suggest that young and middle-aged patients with MGD with no history of hypercholesterolemia may have higher blood cholesterol levels than controls of similar age without MGD. If this finding is confirmed by larger studies, MGD may become a marker of previously unknown hypercholesterolemia and ophthalmologists may increase their role in the early detection of an important risk factor for cardiovascular disease.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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A Randomized Trial of Increasing Patching for Amblyopia – Corrected Proof

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Objective: After treatment with refractive correction and patching, some patients have residual amblyopia resulting from strabismus or anisometropia. We conducted a clinical trial to evaluate the effectiveness of increasing prescribed daily patching from 2 to 6 hours in children with stable residual amblyopia.Design: Prospective, randomized, multicenter clinical trial.Participants: A total of 169 children aged 3 to <8 years (mean, 5.9 years) with stable residual amblyopia (20/32–20/160) after 2 hours of daily patching for at least 12 weeks.Intervention: Random assignment to continue 2 hours of daily patching or increase patching time to an average of 6 hours/day.Main Outcome Measures: Best-corrected visual acuity (VA) in the amblyopic eye after 10 weeks.Results: Baseline VA was 0.44 logarithm of the minimum angle of resolution (logMAR) (20/50−2). Ten weeks after randomization, amblyopic eye VA had improved an average of 1.2 lines in the 6-hour group and 0.5 line in the 2-hour group (difference in mean VA adjusted for acuity at randomization = 0.6 line; 95% confidence interval, 0.3–1.0; P = 0.002). Improvement of 2 or more lines occurred in 40% of participants patched for 6 hours versus 18% of those who continued to patch for 2 hours (P = 0.003).Conclusions: When amblyopic eye VA stops improving with 2 hours of daily patching, increasing the daily patching dosage to 6 hours results in more improvement in VA after 10 weeks compared with continuing 2 hours daily.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Reproducibility of a Long-Range Swept-Source Optical Coherence Tomography Ocular Biometry System and Comparison with Clinical Biometers – Corrected Proof

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Objective: To demonstrate a novel swept source optical coherence tomography (SS-OCT) imaging device using a vertical cavity surface-emitting laser (VCSEL) capable of imaging the full eye length and to introduce a method using this device for noncontact ocular biometry. To compare the measurements of intraocular distances using this SS-OCT instrument with commercially available optical and ultrasound biometers. To evaluate the intersession reproducibility of measurements of intraocular distances using SS-OCT.Design: Evaluation of technology.Participants: Twenty eyes of 10 healthy subjects imaged at the New England Eye Center at Tufts Medical Center and Massachusetts Institute of Technology between May and September 2012.Methods: Averaged central depth profiles were extracted from volumetric SS-OCT datasets. The intraocular distances, such as central corneal thickness (CCT), aqueous depth (AD), anterior chamber depth (ACD), crystalline lens thickness (LT), vitreous depth (VD), and axial length (AL), were measured and compared with a partial coherence interferometry device (IOLMaster; Carl Zeiss Meditec, Inc., Dublin, CA) and an immersion ultrasound (IUS) A-scan biometer (Axis-II PR; Quantel Medical, Inc., Cournon d’Auvergne Cedex, France).Main Outcome Measures: Reproducibility of the measurements of intraocular distances, correlation coefficients, and intraclass correlation coefficients.Results: The standard deviations of the repeated measurements of intraocular distances using SS-OCT were 6 μm (CCT), 16 μm (ACD), 14 μm (AD), 13 μm (LT), 14 μm (VD), and 16 μm (AL). Strong correlations among all 3 biometric instruments were found for AL (r > 0.98). The AL measurement using SS-OCT correlates better with the IOLMaster (r=0.998) than with IUS (r=0.984). The SS-OCT and IOLMaster measured higher AL values than ultrasound (175 and 139 μm, respectively). No statistically significant difference in ACD between the optical (SS-OCT or IOLMaster) and ultrasound methods was detected. High intersession reproducibility of SS-OCT measurements of all intraocular distances was observed with intraclass correlation coefficients >0.99.Conclusions: The SS-OCT using VCSEL technology enables full eye length imaging and high-precision, noncontact ocular biometry. The measurements with the prototype SS-OCT instrument correlate well with commercial biometers. The SS-OCT biometry has the potential to provide clinically useful comprehensive biometric parameters for pre- and postoperative eye evaluation.Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references.

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