Author: Ophthalmology

Long-term Changes in Visual Acuity in an Older Population over a 15-Year Period: The Blue Mountains Eye Study – Corrected Proof

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Purpose: To describe the change in visual acuity (VA) and incidence of visual impairment (VI) in an older population over a 15-year period.Design: Population-based cohort.Participants: Of the 3654 participants of the Blue Mountains Eye Study (BMES) baseline examination from 1992 through 1994, 1149 were re-examined during the 15-year follow-up between 2007 and 2010.Methods: Best-corrected VA by means of subjective refraction was measured with a logarithm of the minimum angle of resolution chart using Early Treatment Diabetic Retinopathy Study methods at each examination.Main Outcome Measures: Unilateral VI was defined as VA worse than 20/40 and blindness was defined as VA worse than 20/200 in the worse eye. Incident bilateral VI and blindness were determined according to VA in the better eye at the 15-year visit. Doubling of the visual angle was defined as a loss of 15 letters or more from baseline to the 15-year visit. Halving of the visual angle was defined as a VA improvement of 15 letters or more over the same period. Causes of VI were determined at examination, by photographic grading, and from medical records.Results: Cumulative 15-year incidence of unilateral and bilateral VI was 12.3% (95% confidence interval [CI], 11.0–13.6) and 5.2% (95% CI, 4.3–6.1), respectively, and for unilateral and bilateral blindness, the cumulative incidence was 3.7% (95% CI, 3.0–4.4) and 0.9% (95% CI, 0.5–1.3), respectively. These incidence rates increased significantly with increasing age (P<0.01 for trend). Doubling and halving of the visual angle occurred in 6.9% (95% CI, 5.9–7.9) and 1.6% (95% CI, 1.0–2.2) of participants, respectively. Cataract accounted for 48.5% of unilateral and bilateral incident VI, followed by age-related macular degeneration (26.9%). Age-related macular degeneration accounted for 56.9% of unilateral and bilateral incident blindness cases, followed by cataract (20.7%).Conclusions: These data provide population-based estimates of long-term incidence of visual impairment among older persons. Our estimate for cumulative incidence of blindness, accounting for competing risk of death, was similar to that of the Beaver Dam Eye Study (BDES) after age standardization. However, our estimate for cumulative incidence of VI was lower compared with that observed in the BDES population. This difference may be explained in part by a higher mortality rate among our population.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Preterm Birth and Later Retinal Detachment: A Population-Based Cohort Study of More than 3 Million Children and Young Adults – Corrected Proof

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Objective: Ophthalmologic complications after preterm birth are common. Small studies show an association between retinopathy of prematurity and later retinal detachment. There are no population-based studies of preterm birth and risk of retinal detachment, which was the objective of the current investigation.Design: Nationwide Swedish cohort study based on population registries.Participants: Of 3 423 697 subjects born in Sweden, 1 271 725 were born between 1973 and 1986 (i.e., before the national screening program for retinopathy of prematurity started), and 2 151 972 were born between 1987 and 2008. The participants were followed up from 1 year of age until 2009.Methods: Unadjusted and adjusted hazard ratios (HRs) for retinal detachment were calculated using Cox proportional hazards regression.Main Outcome Measures: Incident retinal detachment, as defined by a diagnosis in the Swedish Patient Register (both inpatient and hospital-based outpatient data).Results: During follow-up (median follow-up, 17.4 years), 1749 subjects were diagnosed with retinal detachment. Among the 188 852 subjects born prematurely (i.e., at <37 weeks of gestation), there were 124 cases of retinal detachment, of which 42 occurred in the 20 470 subjects born before 32 weeks of gestation. Compared with subjects born at term (37–41 weeks), the adjusted HR for retinal detachment after extremely preterm birth (<28 weeks of gestation) was 19.2 (95% confidence interval [CI], 10.3–35.8) for births between 1973 and 1986 and 8.95 (95% CI, 3.98–20.1) for births between 1987 and 2008. The corresponding HRs in subjects born very prematurely (28–31 weeks) were 4.32 (95% CI, 2.70–6.90) and 2.80 (95% CI, 1.38–5.69), respectively. Moderately preterm birth (32–36 weeks) was not associated with an increased risk of retinal detachment.Conclusions: Birth before 32 weeks of gestation is associated with a substantially increased relative risk of retinal detachment. These findings may have implications for ophthalmologic follow-up of children and adults born very prematurely.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Diagnostic Potential of Iris Cross-sectional Imaging in Albinism Using Optical Coherence Tomography – Corrected Proof

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Purpose: To characterize in vivo anatomic abnormalities of the iris in albinism compared with healthy controls using anterior segment optical coherence tomography (AS-OCT) and to explore the diagnostic potential of this technique for albinism. We also investigated the relationship between iris abnormalities and other phenotypical features of albinism.Design: Prospective cross-sectional study.Participants: A total of 55 individuals with albinism and 45 healthy controls.Methods: We acquired 4.37×4.37-mm volumetric scans (743 A-scans, 50 B-scans) of the nasal and temporal iris in both eyes using AS-OCT (3-μm axial resolution). Iris layers were segmented and thicknesses were measured using ImageJ software. Iris transillumination grading was graded using Summers and colleagues’ classification. Retinal OCT, eye movement recordings, best-corrected visual acuity (BCVA), visual evoked potential (VEP), and grading of skin and hair pigmentation were used to quantify other phenotypical features associated with albinism.Main Outcome Measures: Iris AS-OCT measurements included (1) total iris thickness, (2) stroma/anterior border (SAB) layer thickness, and (3) posterior epithelial layer (PEL) thickness. Correlation with other phenotypical measurements, including (1) iris transillumination grading, (2) retinal layer measurements at the fovea, (3) nystagmus intensity, (4) BCVA, (5) VEP asymmetry, (6) skin pigmentation, and (7) hair pigmentation (of head hair, lashes, and brows).Results: The mean iris thickness was 10.7% thicker in controls (379.3±44.0 μm) compared with the albinism group (342.5±52.6 μm; P>0.001), SAB layers were 5.8% thicker in controls (315.1±43.8 μm) compared with the albinism group (297.7±50.0 μm; P=0.044), and PEL was 44.0% thicker in controls (64.1±11.7 μm) compared with the albinism group (44.5±13.9 μm; P<0.0001). The most ciliary quartile of the PEL yielded a sensitivity of 85% and specificity of 78% for detecting albinism. Phenotypic features of albinism, such as skin and hair pigmentation, BCVA, and nystagmus intensity, were significantly correlated to AS-OCT iris thickness measurements.Conclusions: We have characterized in vivo abnormalities of the iris associated with albinism for the first time and show that PEL thickness is particularly affected. We demonstrate that PEL thickness has diagnostic potential for detecting iris abnormalities in albinism. Anterior segment OCT iris measurements are significantly correlated to BCVA and nystagmus intensity in contrast to iris transillumination grading measurements that were not.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Evaluation of Ocular Surface Disease in Patients with Glaucoma – Corrected Proof

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Purpose: To evaluate the subjective and objective measures of ocular surface disease in patients with glaucoma.Design: Cross-sectional study.Participants: Sixty-four glaucoma subjects with bilateral visual field (VF) loss and 59 glaucoma suspects with normal VFs.Methods: Consecutive patients were recruited prospectively from the Wilmer Eye Institute Glaucoma Clinic.Main Outcome Measures: Tear film breakup time (TBUT), corneal staining score (0–15), and Schirmer’s test results were included as objective metrics, whereas the Ocular Surface Disease Index (OSDI) questionnaire was administered to assess symptoms. Total OSDI score, vision-related subscore (derived from questions about vision and task performance), and discomfort-related subscore (derived from questions about ocular surface discomfort) were calculated for each subject.Results: Seventy-five percent (48/64) of glaucoma subjects and 41% (24/59) of glaucoma suspects were receiving topical medications. The corneal staining grade was greater in glaucoma subjects than in glaucoma suspects (6.4 vs. 4.1; P<0.001), but groups did not differ with regard to TBUT or Schirmer’s results (P>0.20 for both). Multivariate regression models showed that topical glaucoma therapy burden was associated with a significantly higher total corneal staining grade (β, +0.9 for each additional glaucoma drop; 95% confidence interval [CI], 0.5–1.3; P<0.001), but not with TBUT or Schirmer’s results (P>0.20 for both). Glaucoma subjects had significantly higher total OSDI scores than glaucoma suspects (16.7 vs. 7.9; P<0.001). This largely was the result of higher vision-related subscores in the glaucoma group (11.1 vs. 3.3; P<0.001). Ocular discomfort–related subscores, however, were similar in both groups (5.7 vs. 4.6; P = 0.30). In multivariate analyses, each 5-decibel decrement in better-eye VF mean deviation was associated with a 4.7-point increase in total OSDI score (95% CI, 1.9–7.5; P = 0.001) and a 3.7-point increase in the vision-related subscore (95% CI, 1.7–5.6; P<0.001) but did not predict a higher discomfort-related subscore (β, 1.1 point; P = 0.07). Topical glaucoma therapy burden was not associated with higher total OSDI score or vision- or discomfort-related subscore (P>0.20 for all).Conclusions: Glaucoma is associated with significant ocular surface disease, and topical glaucoma therapy burden seems predictive of corneal staining severity. However, OSDI is a poor metric for capturing ocular surface disease in glaucoma because symptoms seem to be related largely to VF loss.Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references.

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Prevalence of Blindness and Outcomes of Cataract Surgery in Hainan Province in South China – Corrected Proof

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Objective: To define the prevalence of blindness and visual impairment (VI) in people in rural Hainan using the rapid assessment of avoidable blindness (RAAB) and to report the outcomes of cataract surgery among the residents.Design: Population-based, cross-sectional survey.Participants: A total of 6482 rural residents of the Hainan province.Methods: A total of 136 clusters, each of which consisted of 50 people aged ≥50 years, were selected through probability-proportionate-to-size sampling. Door-to-door visits were performed by 2 outreach teams. Visual acuity (VA) was measured on site, and those with VA <6/18 in either eye were examined by an ophthalmologist. Causes of blindness and VI were determined. The causes of poor visual outcome after cataract surgery were evaluated. Information regarding barriers to receiving surgery was collected by trained interviewers.Main Outcome Measures: Prevalence and causes of blindness (VA <3/60), severe VI (SVI) (VA <6/60 but ≥3/60), and VI (VA <6/18 but ≥6/60) based on presenting VA (PVA) were assessed. Outcomes of cataract surgery performed in public and private hospitals and charitable organizations were compared.Results: A total of 6482 subjects were examined (response rate, 95.3%). The sample prevalence of blindness was 4.4% (95% confidence interval [CI], 2.0–6.8). The prevalence of SVI and VI was 1.9% (95% CI, 0–4.3) and 9.9% (95% CI, 7.6–12.2), respectively. Age and sex were associated with increased prevalence of blindness, SVI, and VI. Overall, cataract accounted for approximately 60% of blindness and SVI. Of the 524 eyes that had received cataract surgery, 87.2% had intraocular lenses implanted, 21% had a poor visual outcome (PVA <6 /60), and 20% had a borderline visual outcome (PVA <6/18 but ≥6/60). Eyes that received surgery in charitable organizations had a higher rate of intraocular lens implantation and good visual outcome (VA ≥6/18) compared with eyes that were operated on elsewhere.Conclusions: The prevalence of blindness, SVI, and VI was high among rural residents in Hainan. Cataract remained the leading cause of avoidable blindness. Outcomes of cataract surgery performed in public hospitals were suboptimal. Quality-control initiatives should be introduced to improve cataract surgery outcomes.Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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