Diabetic retinopathy screening: can the viewing monitor influence the reading and grading outcomes

Purpose

To evaluate the accuracy of different viewing monitors for image reading and grading of diabetic retinopathy (DR).

Design

Single-centre, experimental case series—evaluation of reading devices for DR screening.

Method

A total of 100 sets of three-field (optic disc, macula, and temporal views) colour retinal still images (50 normal and 50 with DR) captured by FF 450 plus (Carl Zeiss) were interpreted on 27-inch iMac, 15-inch MacBook Pro, and 9.7-inch iPad. All images were interpreted by a retinal specialist and a medical officer. We calculated the sensitivity and specificity of 15-inch MacBook Pro and 9.7-inch iPad in detection of DR signs and grades with reference to the reading outcomes obtained using a 27-inch iMac reading monitor.

Results

In detection of any grade of DR, the 15-inch MacBook Pro had sensitivity and specificity of 96% (95% confidence interval (CI): 85.1–99.3) and 96% (95% CI: 85.1–99.3), respectively, for retinal specialist and 91.5% (95% CI: 78.7–97.2) and 94.3% (95% CI: 83.3–98.5), respectively, for medical officer, whereas for 9.7-inch iPad, they were 91.8% (95% CI: 79.5–97.4) and 94.1% (95% CI: 82.8–98.5), respectively, for retinal specialist and 91.3% (95% CI: 78.3–97.1) and 92.6% (95% CI: 81.3–97.6), respectively, for medical officer.

Conclusion

The 15-inch MacBook Pro and 9.7-inch iPad had excellent sensitivity and specificity in detecting DR and hence, both screen sizes can be utilized to effectively interpret colour retinal still images for DR remotely in a routine, mobile or tele-ophthalmology setting. Future studies could explore the use of more economical devices with smaller viewing resolutions to reduce cost implementation of DR screening services.     

New superior–inferior visual field asymmetry indices for detecting POAG and their agreement with the glaucoma hemifield test

Purpose

To describe and measure the discriminatory performance of three new superior–inferior asymmetry indices for detecting primary open angle glaucoma (POAG) and to compare these with the glaucoma hemifield test (GHT).

Methods

In all, 412 control and 247 POAG eyes were selected from a visual field database of patients attending the Manchester Royal Eye Hospital. Age-adjusted defect asymmetries were calculated for each of the 22 vertically mirrored test point pairs used in the GHT. The three new indices, hemifield mean difference (HMD) and hemifield standard deviation (HSD) of the asymmetry values along with the number of test pairs (NP) falling outside the 85% probability limits of the control population, were calculated. ROC curves of the indices and GHT were constructed. Agreement between the indices was explored with a proportional Venn diagram and 3 × 3 contingency tables. Cases of disagreement between the indices were reviewed.

Results

The area under the ROC curves were HMD=0.745 (95% confidence interval (CI) 0.705–0.786), HSD=0.864 (95% CI 0.833–0.894), NP=0.863 (95% CI 0.832–0.893) and GHT=0.792 (95% CI 0.754–0.829). The Venn diagram and contingency tables highlighted the good agreement between HSD, NP and GHT. Agreement was 78% (HSD vs GHT) and 82% (NP vs GHT) in the control sample and 70% (HSD vs GHT) and 71% (NP vs GHT) in the POAG sample. Five cases are presented where disagreement existed between the indices.

Conclusions

The new HSD and NP asymmetry indices perform better than GHT in differentiating between normal and POAG eyes in this data set. GHT can fail to detect significant asymmetry, detected by HSD and NP, when an early defect crosses sector boundaries.     

Prevalence of glaucoma in patients with moderate to severe obstructive sleep apnea: ocular morbidity and outcomes in a 3 year follow-up study

Purpose

This study was conducted to investigate the prevalence and progression of glaucoma in patients receiving treatment for obstructive sleep apnea (OSA). We also investigated whether there is an association between severity of OSA and the incidence of glaucoma.

Methods

A total of 39 patients aged >30 years who had been diagnosed with moderate and severe OSA in the sleep clinic at Hamad General Hospital were assessed for the presence of glaucoma. The severity of OSA was graded as mild, moderate, or severe based on American Association of Sleep Medicine (AASM) criteria using the apnea hypopnea index. Before enrollment, all patients underwent a complete ophthalmic examination including serial visual field tests, optical coherence tomography (OCT) with fundus photographs, and pachymetry. Enrolled patients were followed up in the ophthalmology outpatient clinic and sleep clinic for a period of 3 years.

Results

Examinations found that 8 (20.5% 95% confidence interval (CI) 9.9–37%) of the 39 patients with OSA had glaucoma. Six (75% 95% CI 36–96%) of these patients had normal-tension glaucoma (NTG) and two (25% 95% CI 4.5–64.4%) patients had high-tension glaucoma. Among the 27 patients with severe OSA, 7 (25.9% 95% CI 8–34%) had glaucoma, and among 12 patients with moderate OSA, 1 (8.3% 95% CI 0.1–15%) had glaucoma. During the course of follow-up, two patients who previously did not have glaucoma were reclassified as NTG and two patients with glaucoma deteriorated. A higher prevalence of glaucoma in the severe OSA group compared with the moderate OSA group was found, albeit a statistically significant difference could not be attained (P=0.4).

Conclusions

Our study showed that severe OSA is an important risk factor for developing glaucoma. Adequate treatment of OSA, along with optimal ophthalmic care, resulted in better control of glaucoma.     

Foldable vs rigid lenses after phacoemulsification for cataract surgery: a randomised controlled trial

Purpose

To compare the outcomes of phacoemulsification with either a 2.5-mm clear corneal incision and a foldable intraocular lens (IOL) or a 5-mm sclerocorneal tunnel incision and a rigid polymethyl methacrylate (PMMA) IOL.

Methods

In a prospective, randomised clinical trial of phacoemulsification cataract surgery, 1200 patients received either a foldable hydrophilic acrylic IOL through a 2.5-mm corneal incision or an inexpensive rigid PMMA IOL via a 5-mm sclerocorneal tunnel. Intra- and post-operative data and visual acuity at discharge, 6 weeks, and 1 year follow-up were analysed.

Results

At 1 year after surgery, 996 (83.0%) patients were followed up with an uncorrected visual acuity of 6/18 or better in 90.3% of the foldable and 94.3% in the rigid IOL group (risk ratio (RR) 0.96, 95% confidence intervals (CI) 0.92–0.99). Poor outcome (best-corrected acuity 6/60 or worse) occurred in 1.0% and 0.4%, respectively (RR 4.28, 95% CI 0.48–38.18). The surgical cost of consumables and overall surgical time were similar in both groups; however, the cost of the foldable IOL was eight times higher than the PMMA IOL. Posterior capsule opacification was more common in the rigid IOL group at 12 months (36.1% vs 23.3%); however, this did not affect post-operative vision.

Conclusion

In the hands of experienced cataract surgeons, phacoemulsification with implantation of a foldable or a rigid IOL gives excellent results. Using an inexpensive rigid PMMA IOL will make phacoemulsification more affordable for poor patients in low- and middle-income countries.     

Detection of asymmetric glaucomatous damage using automated pupillography,the swinging flashlight method and the magnified-assisted swinging flashlight method

Purpose

To determine the sensitivity and specificity of various methods of detecting a relative afferent pupillary defect (RAPD) in patients with glaucoma-related diagnoses.

Patients and methods

Patients underwent RAPD evaluation using the swinging flashlight method (SFM), the magnifier-assisted SFM, and pupillography using the Konan RAPDx. Main outcome measures were sensitivity and specificity of three methods of RAPD evaluation in detecting visual field mean deviation (MD), cup to disc ratio (CDR), disc damage likelihood scale (DDLS), and retinal nerve fiber layer (RNFL) asymmetry.

Results

Eighty-one consecutive patients from the Wills Eye Hospital glaucoma service were enrolled, 60 with glaucoma and 21 with ocular hypertension or glaucoma suspect. Thirty-one percent of subjects had MD asymmetry>5 dB, 19.7% had CDR asymmetry≥0.20, 26.7% had DDLS asymmetry≥2, and 38.2% had RNFL asymmetry>10 microns. Sensitivity values for pupillography were 93.3% (95% CI, 68.1–99.8) for detecting MD asymmetry, 80.0% (95% CI, 51.9–95.7) for CDR asymmetry, 100.0% (95% CI, 73.5–100.0) for DDLS asymmetry, and 69.2% (95% CI, 38.6–90.9) for RNFL asymmetry. Specificity values were 41.2% (95% CI, 24.7–59.3) for detecting MD asymmetry, 32.8% (95% CI, 21.3–46.0) for CDR asymmetry, 33.3% (95% CI, 18.0–51.8) for DDLS asymmetry, and 42.9% (95% CI, 21.8–66.0) for RNFL asymmetry. Pupillography amplitude score was correlated with MD asymmetry (r²=0.41, P<0.001) and area under the curve was 0.84.

Conclusion

Automated pupillography had higher sensitivity and lower specificity in detecting MD, CDR, DDLS, and RNFL asymmetry. Within the bounds of the cohort tested, this method had limited case-finding ability.     

Dementia is associated with open-angle glaucoma: a population-based study

Purpose

Previous epidemiologic studies that focused on the association between open-angle glaucoma (OAG) and dementia showed inconsistent results. In the present study, we explored the association between OAG and dementia in an ethnic Chinese (ie, Taiwanese) population using a population-based data set.

Methods

We retrieved data on study subjects for this case-control study from the Longitudinal Health Insurance Database 2000. We identified 7770 patients who had a diagnosis of dementia as cases, and 7770 subjects matched in terms of sex and age, which were randomly extracted as controls. A conditional logistic regression conditioned on age group, sex, and index year was used to assess the association of dementia with previously diagnosed OAG among the sampled patients.

Results

Of 15 540 patients, 1.70% had prior OAG, including 2.02% of the dementia group and 1.38% of the controls. After adjusting for patient socioeconomic characteristics and comorbid medical disorders, dementia patients were more likely to have had prior OAG than controls (odds ratio (OR): 1.44; 95% confidence interval (CI): 1.12–1.85; P<0.01). In addition, female dementia patients were more likely to have had prior OAG than controls (OR: 1.93; 95% CI: 1.35–2.77; P<0.001), whereas no statistical difference in prior OAG between male dementia patients and controls was found.

Conclusions

Female dementia patients were associated with a higher proportion of prior OAG than were the controls.     

Polypropylene vs silicone Ahmed valve with adjunctive mitomycin C in paediatric age group: a prospective controlled study

Purpose

To compare the results of silicone and polypropylene Ahmed glaucoma valves (AGV) implanted during the first 10 years of life.

Methods

A prospective study was performed on 50 eyes of 33 patients with paediatric glaucoma. Eyes were matched to either polypropylene or silicone AGV. In eyes with bilateral glaucoma, one eye was implanted with polypropylene and the other eye was implanted with silicone AGV.

Results

Fifty eyes of 33 children were reviewed. Twenty five eyes received a polypropylene valve, and 25 eyes received a silicone valve. Eyes implanted with silicone valves achieved a significantly lower intraocular pressure (IOP) compared with the polypropylene group at 6 months, 1 year, and 2 years postoperatively. The average survival time was significantly longer (P=0.001 by the log-rank test) for the silicone group than for the polypropylene group and the cumulative probability of survival by the log-rank test at the end of the second year was 80% (SE: 8.0, 95% confidence interval (CI): 64–96%) in the silicone group and 56% (SE: 9.8, 95% CI: 40–90%) in the polypropylene group. The difference in the number of postoperative interventions and complications between both groups was statistically insignificant.

Conclusion

Silicone AGVs can achieve better IOP control, and longer survival with less antiglaucoma drops compared with polypropylene valves in children younger than 10 years.     

Cognitive function,drusen, and age-related macular degeneration: a cross-sectional study

Purpose

To examine the cross-sectional relationship between drusen, late age-related macular degeneration (AMD), and cognitive function.

Methods

We included 2149 stroke-free participants from the population-based Tromsø Study in Norway. Retinal photographs were graded for presence of drusen and AMD. Cognitive function was assessed using the verbal memory test (short verbal memory), digit-symbol coding test (processing speed), and the tapping test (psychomotor tempo). We assessed the relationship between drusen, late AMD, and cognitive test scores, adjusted for potential confounders.

Results

Late AMD was associated with decreased performance in the verbal memory test (standardized β=−0.23, 95% confidence interval (CI): −0.51 to −0.01). Intermediate and large drusen were associated with decreased performance in the digit-symbol coding test (standardized β=−0.14 and –0.19, 95% CIs: −0.23 to −0.05 and −0.29 to −0.09, respectively). Participants with large drusen were more likely to have test scores in the lowest quartile of the digit-symbol coding test (odds ratio (OR)=1.9, 95% CI: 1.1–3.5) and the tapping test (OR=1.6, 95% CI: 1.0–2.6), but not in the verbal memory test (OR=1.0, 95% CI: 0.6–1.6).

Conclusions

The findings suggest a relationship between drusen deposition and reduced cognitive function. Although the relationships between drusen, late AMD, and the cognitive test results varied in strength and significance across the types of cognitive test, and may partly have been caused by residual confounding, it is not unlikely that a genuine but weaker relationship exists between drusen deposition and cognitive decline.     

The impact of the Virtual Ophthalmology Clinic on medical students' learning: a randomised controlled trial

Aim

The Virtual Ophthalmology Clinic (VOC) is an interactive web-based teaching module, with special emphasis on history taking and clinical reasoning skills. The purpose of this study was to determine the impact of VOC on medical students'' learning.

Methods

A randomised controlled trial (RCT) was conducted with medical students from the University of Sydney (n=188) who were randomly assigned into either an experimental (n=93) or a control group (n=95). A pre- and post-test and student satisfaction questionnaire were administered. Twelve months later a follow-up test was conducted to determine the long-term retention rate of graduates.

Results

There was a statistically significant (P<0.001) within-subject improvement pre- to post rotation in the number of correctly answered questions for both the control and experimental groups (mean improvement for control 10%, 95% CI 1.3–2.6, and for experimental 17.5%, 95% CI 3.0–4.0). The improvement was significantly greater in the experimental group (mean difference in improvement between groups 7.5%, 95% CI 0.8–2.3, P<0.001). At 12 months follow-up testing, the experimental group scored on average 1.6 (8%) (95%CI 0.4 to 2.7, P=0.007) higher than the controls.

Conclusion

On the basis of a statistically significant improvement in academic performance and highly positive student feedback, the implementation of VOC may provide a means to address challenges to ophthalmic learning outcomes in an already crowded medical curriculum.     

Early surgery for epiretinal membrane preserves more vision for patients

Purpose

To establish whether early vitrectomy for epiretinal membrane (ERM) is preferable to delayed surgery.

Methods

We carried out a retrospective study of 120 eyes from 120 patients with pre-operative visual acuity (VA) of 6/60 or better. Pre-operative logMAR score was considered to act as an appropriate proxy measure for time of surgical procedure, with scores of 0.3 or less considered to represent early surgery, scores of 0.4 or 0.5 considered to represent medium surgery, and scores of 0.6 or more considered to represent late surgery for ERM. Patients were either pseudophakic at the time of vitrectomy or underwent combined phaco-vitrectomy for symptomatic ERM.

Results

Evaluation of parameter coefficients indicated that controlling for other factors, a delay of the surgical procedure from a state of early to medium corresponded to an increase (ie, disbenefit) of 0.074 units in post-operative logMAR score (95% confidence interval −0.001–0.15). A delay of the surgical procedure from a state of early to late corresponded to an increase (ie, disbenefit) of 0.21 units in post-operative logMAR score (95% confidence interval 0.13–0.29). Mean post-operative VA for early surgery was 0.16, out of which 36.2% of patients had a LogMAR score of 0.1 or better. This is in comparison to 17.2% in late ERM (those with a pre-operative logMAR score of 0.6 or more).

Conclusion

We conclude that early surgery is associated with a lower (ie, better) post-operative logMAR score. Vitrectomy for early symptomatic ERM, in carefully selected patients, is beneficial in preserving excellent vision and allows quicker visual rehabilitation.     

Validation of a new photogrammetric technique to monitor the treatment effect of Botulinum toxin in synkinesis

Aims

To validate a new photogrammetric technique for quantifying eye surface area and using this to quantify the degree of improvement in symmetry in patients with oral–ocular synkinesis following Botulinum toxin injection.

Study design

Feasibility study and retrospective outcomes analysis

Methods

Ten patients'' photographs were chosen from a photographic database. Their eye surface areas were measured independently by two raters using a graphics tablet. One rater repeated the procedure after 15 days. Bland–Altman plots were computed, ascertaining inter-rater and intra-rater variability. The eye surface areas of 19 patients were then derived from photographs taken before and after Botulinum toxin injections. Paired t-tests were used to analyse the significance of the difference in pre- and post-treatment symmetry.

Results

Ninety per cent of eye surface areas derived from the two raters were within a coefficient of variation of 0.1 (95% CI: 0.05–0.15). Similarly, 90% of eye surface areas derived from one rater had a coefficient of variation of 0.08 (95% CI: 0.04–0.12). Botulinum toxin significantly reduced synkinesis resulting from lip puckering, Mona Lisa smiling and Hollywood smiling (P<0.05).

Conclusions

We have proposed a clinically valid tool for quantifying the effects of Botulinum toxin treatment for oral–ocular synkinesis. We recommend this method be used to monitor the response of such patients when receiving Botulinum toxin treatment.

Level of evidence

2c.     

Relevance of TSH-receptor antibody levels in predicting disease course in Graves' orbitopathy: comparison of the third-generation TBII assay and Mc4-TSI bioassay

Aims

To investigate if TSH-receptor antibody (TRAb) levels measured in early Graves'' orbitopathy (GO) stages are predictive of clinical disease course beyond 1 year after initial GO diagnosis and to compare performance of two newly developed TRAb assays (third-generation thyrotropin-binding inhibitor immunoglobulin (TBII) assay vs Mc4-thyroid-stimulating immunoglobulin (TSI) bioassay) in predicting disease course.

Methods

Newly diagnosed, untreated GO patients whose duration of ocular symptoms was less than 6 months were included. One year after initial diagnosis, all patients were classified as presenting either a mild (Group 1) or severe course (Group 2) according to their clinical manifestations. The measurements of two TRAb assays at initial GO diagnosis were used for analysis.

Results

Data from 112 patients were available for analysis. Seventy-three patients (65.2%) were designated as Group 1, and 39 patients (34.8%) as Group 2. Patients with higher initial TRAb levels demonstrated a higher risk of severe disease course upon multiple regression analysis (P<0.01). The cutoff values for the prediction of severe course of the third-generation TBII and Mc4-TSI assays were 10.67 IU/l and 555.10%, respectively, with assay specificities of 84.9 and 89.0%. The TBII assay predictive power (area under the curve (AUC)=0.817; 95% confidence interval (CI) =0.732–0.902) was equivalent to the TSI bioassay (AUC=0.868, 95% CI=0.803–0.934) (P=0.203).

Conclusions

The predictive power of the third-generation TBII assay and Mc4-TSI bioassay are similarly strong. Measurement of TRAb using either third-generation TBII or Mc4-TSI in early GO periods would provide important prognostic information on future GO course.     

Intravitreal anti-vascular endothelial growth factor monotherapy for large submacular hemorrhage secondary to neovascular age-related macular degeneration

Purpose

To evaluate the efficacy of anti-vascular endothelial growth factor (VEGF) monotherapy for large submacular hemorrhage (SMH) secondary to neovascular age-related macular degeneration (nAMD).

Methods

A total of 49 treatment-naive patients (49 eyes) with large SMH (more than five disc areas (DAs)) secondary to nAMD were retrospectively included. All patients were treated with an initial series of 3 monthly intravitreal anti-VEGF injections, followed by as-needed injections. At the 12-month follow-up, changes in best-corrected visual acuity (BCVA), hemorrhage area, central foveal thickness, and development of vitreous hemorrhage after treatment were evaluated.

Results

The mean SMH area was 13.9±8.8 disk areas (DAs) and mean symptom duration was 7.25±5.9 days at baseline. The mean number of injections was 4.49±1.61. Twelve months after treatment, the mean BCVA significantly improved from 1.14±0.61 logarithm of the minimum angle of resolution (logMAR; 20/276, Snellen equivalent) to 0.82±0.53 logMAR (20/132; P=0.002). Twenty-four eyes (49%) showed improvement of more than three lines of BCVA at 12 months after treatment. Baseline BCVA (odds ratio (OR), 5.119; 95% confidence interval (CI), 1.993–9.545; P=0.004), duration of symptoms (OR, 0.727; 95% CI, 0.332–0.952; P=0.024), hemorrhage area (OR, 0.892; 95% CI, 0.721–0.965; P=0.011), and baseline central foveal thickness (OR, 0.881; 95% CI, 0.722–0.945; P=0.032) were significantly associated with good visual acuity 12 months after treatment.

Conclusions

Intravitreal anti-VEGF monotherapy is a valuable treatment option for large SMH secondary to nAMD.     

The surgical approach to the management of anterior uveal melanomas

Purpose

Surgical excision of peripheral iris or ciliary body melanomas can be performed antero-posteriorly (irido-cyclectomy) with mydriasis or postero-anteriorly (cyclo-iridectomy) with miosis. The aim of this study was to evaluate the results of both surgical techniques.

Methods

Patients were enrolled in the study if they underwent irido-cyclectomy or cyclo-iridectomy for iris and/or ciliary body melanoma at the Liverpool Ocular Oncology Centre between 1993 and 2012.

Results

The 24 patients (8 male, 16 female) had a median age of 57 years. The largest median basal tumour diameter and the median tumour thickness were 4.8 and 2.2 mm, respectively. The resection was performed antero-posteriorly in 9 (37%) patients and postero-anteriorly or circumferentially in 15 (63%). Nine tumours contained epithelioid cells. Genetic studies were performed in 10 patients, showing chromosome 3 loss in two. Postoperative complications included hypotony in 9 (37%) patients, cataract in 8 (33%), hyphaema in 8 (33%), cyclodialysis in 1 (4%), wound dehiscence in 1 (4%) and bullous keratopathy in 1 patient (4%). The median follow-up time was 2.4 years. The last known visual acuity was 6/6–6/12 in 20 (91%) patients and 6/18–6/60 in 2 (9%), with 2 (8%) requiring secondary enucleation. Local tumour recurrence developed in 1 patient (4%). Two (8%) patients died of metastatic disease.

Conclusions

Surgical resection of peripheral iris melanomas achieves high rates of visual conservation and local tumour control and may be the preferred option when tissue is required for laboratory studies.     

Visual outcomes and ocular morbidity of patients with uveitis referred to a tertiary center during first year of follow-up

Purpose

To describe the visual outcomes and morbidity of newly referred uveitis patients.

Methods

Retrospective cohort study of 133 newly referred uveitis patients with active uveitis who required care in a tertiary center for at least 1 year. Main outcomes were best-corrected visual acuity (BCVA) at referral and 1 year after referral, duration of visual impairment, systemic medications used, as well as all complications and surgeries during the first year of follow-up. Generalized estimating equation models was used to assess prognosticators for poor BCVA.

Results

The mean age at onset of uveitis was 43 years. The proportion of patients with at least one eye with BCVA ≤0.3 decreased from 35% at referral to 26% (P=0.45) at 1-year follow-up. The mean duration of visual impairment in the first year after referral was 4 months per affected eye. At 1-year follow-up, bilateral visual impairment was observed in 4% but at least one ocular complication developed in 66% and 30% of patients required at least one intraocular surgery. Systemic immunosuppressive treatment was required in 35% of patients and the mean number of visits to ophthalmologist was 11 per year, while 8% of patients required hospital admission. Prognosticators for poor visual outcome included surgery undergone before referral (odds ratio (OR), 3; 95% CI, 1–11; P=0.047), visual impairment at referral (OR, 21; 95% CI, 8–54; P<0.001), and glaucoma before referral (OR, 7; 95% CI, 2–28; P=0.007).

Conclusions

Patients with severe uveitis had a favorable BCVA 1 year after referral with only 4% of patients having bilateral visual impairment. This, in contrast to the prolonged duration of visual impairment during the first year of follow-up and the demanding care.     

Increased risk of open-angle glaucoma following chronic rhinosinusitis: a population-based matched-cohort study

Purpose

Anatomically, the eyes and paranasal sinuses are neighboring structures and some studies have mentioned eye disease in conjunction with chronic rhinosinusitis (CRS). However, to the best of our knowledge, no prior research has investigated the risk of developing open-angle glaucoma (OAG) among CRS patients. This study aims to provide an estimated risk of developing OAG among patients with CRS by using a population-based data set in Taiwan.

Methods

This retrospective cohort study used data sourced from the ‘Longitudinal Health Insurance Database 2000''. A total of 15 642 CRS patients were included in the study cohort and 46 926 subjects were randomly extracted as a comparison cohort. A cox proportional-hazards regression analysis was performed to calculate the 5-year risk of subsequently developing OAG following a diagnosis of CRS between the study cohort and the comparison cohort.

Results

The incidence rate of developing OAG over the 5-year follow-up period was 5.45 (95% CI: 4.95–5.98) per 1000 person-years for the study cohort and 2.80 (95% CI: 2.60–3.03) per 1000 person-years for the comparison cohort. After censoring the cases that died over the 5-year period and adjusting for the factors of monthly income, geographic region, hypertension, diabetes, coronary heart disease, hyperlipidemia, and hypothyroidism the hazard ratio for developing OAG over the 5-year period for subjects with CRS to subjects without CRS was 1.73 (95% CI: 1.53–1.96).

Conclusion

We found that those subjects with CRS had a significantly higher risk of developing OAG over the 5-year follow-up period as compared with subjects without CRS.     

Age-related macular degeneration and protective effect of HMG Co-A reductase inhibitors (statins): results from the National Health and Nutrition Examination Survey 2005–2008

Purpose

To determine the association of hydroxymethylglutarylcoenzyme A (HMG Co-A) reductase inhibitor (statin) use with the prevalence of age-related macular degeneration (AMD).

Methods

This cross-sectional study included 5604 participants in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2008, ≥40 years of age, who were ascertained with regard to the diagnosis of AMD, the use of statins, and comorbidities and health-related behaviors such as smoking.

Results

The mean age of participants denying or confirming a history of AMD was 68 (SEM 0.90) and 55 (SEM 0.36) years, respectively. Individuals 68 years of age or older who were classified as long-term users of statins had statistically significant less self-reported AMD (odds ratio (OR) 0.64, 95% confidence interval (CI) 0.49–0.84; P=0.002), after adjusting for potential confounding variables. No significant association was found between the prevalence of AMD and statin consumption among subjects between 40 and 67 years of age (OR 1.61, 95% CI 0.85–3.03; P=0.137).

Conclusions

Our results suggest a possible beneficial effect of statin intake for the prevention of AMD in individuals 68 years of age or older.     

Long term patient-reported benefit from ptosis surgery

Purpose

To assess the long term impact of ptosis surgery on health-related quality-of-life using the Glasgow Benefit Inventory (GBI) patient-reported outcome measure.

Patients and methods

A retrospective case note review was carried out on all patients who had undergone ptosis surgery (6 November 2008 to 5 December 2010) by one surgeon at Royal Bournemouth Hospital. Patient demographics, surgical technique, and complications were recorded. The GBI questionnaire data was obtained by telephone interview.

Results

A total of 62 ptosis operations (33 right, 29 left, of which 18 were bilateral) on 44 patients; 20 male, 24 female were included. Median age 77 years (range: 17–95 years). One wound dehiscence occurred, but no redo ptosis procedures were required. GBI data was obtained on 32 patients (45 ptosis procedures) at a mean follow-up period of 42.8 months postoperatively (range 31–67 months). The mean total GBI score for ptosis surgery was +21.36 (range 0–58.33; 95% confidence interval: 17.28–25.43, P<0.05).

Conclusion

Patients derived a highly significant benefit to their health-related quality-of-life from ptosis surgery measured by the GBI that was maintained for up to 5 years.     

A survey of severe visual impairment in children attending schools for the blind in a coastal district of Andhra Pradesh in South India

Purpose

To identify the major causes of severe childhood visual impairment and blindness among students attending schools for the blind in a coastal district of Andhra Pradesh (AP) in South India.

Methods

Children ≤16 years of age attending six schools for the blind in the study area were interviewed and examined in the year 2009, and causes were classified according to the World Health Organization Program for Prevention of Blindness (WHO/PBL) childhood blindness proforma. A total of 113 children underwent a detailed eye examination by an experienced ophthalmologist.

Results

The major causes of blindness were congenital eye anomalies in 46 children (41.4; 95% confidence interval (CI): 32.3–50.6), followed by retinal disorders in 21 children (18.9% 95% CI: 11.6–26.2), cataract in 9 children (9.7% 95% CI: 2.9–12.9), and corneal conditions (scar and Staphyloma) in 8 children (7.1% 95% CI: 2.4–11.8). More than half the children (56.6%) were blind due to conditions that could have been treated or prevented.

Discussion

Congenital anomalies were found to be the most common cause of blindness. The majority of the cases were due to avoidable causes of blindness. Therefore, robust screening measures may help reduce the burden of visual impairment in children.     

Risk factors for contact lens-related microbial keratitis in Singapore

Purpose:

To investigate independent risk factors for contact lens-related microbial keratitis in Singapore and estimate their impact on disease load.

Methods:

Cases were contact lens wearers presenting to Singapore National Eye Centre with microbial keratitis between 2008 and 2010. Community contact lens wearers were recruited as controls. All wearers completed a previously validated questionnaire describing contact lens wear history, hygiene and compliance habits, and demographics. Risk factors significant in univariate analysis (P<0.2) were evaluated in a multivariate model.

Results:

In all, 58 cases of microbial keratitis and 152 contemporaneous controls were identified. When controlling for other variables, Chinese had a 7 × lower risk compared with other races (95% CI: 2.3–21.3, P=0.001). Those aged between 25 and 44 years were at 3 × increased risk compared with younger wearers (95% CI: 1.1–9.6, P=0.04). Occasional overnight contact lens wear (less often than one night per week) was associated with a 4 × higher risk (95% CI: 1.2–15.4, P=0.03) compared with daily use. Not washing hands before handling was associated with a 13 × increased risk (95% CI: 1.9–84.8, P=0.008). Use of multipurpose solution A carried a 16 × higher risk compared with hydrogen peroxide (95% CI: 1.5–174.0, P=0.02). The combined PAR% for modifiable risk factors (occasional overnight wear, not washing of hands, and MPS A) was 82%.

Conclusions:

Consistent with previous findings, independent risk factors for contact lens-related microbial keratitis include poor hand hygiene, occasional overnight wear, and type of lens care solution. Prolonged overnight or extended contact lens use was infrequent in this population.