Twenty-four hour efficacy with the dorzolamide/timolol-fixed combination compared with the brimonidine/timolol-fixed combination in primary open-angle glaucoma

Aim

The aim of this study is to compare the 24-hour efficacy of dorzolamide/timolol-fixed combination (DTFC) and brimonidine/timolol-fixed combination (BTFC) in primary open-angle glaucoma (POAG).

Methods

One eye each of 77 POAG patients was included in this prospective, observer-masked, crossover comparison. Following a 2-month timolol run-in period, patients had three intraocular pressure (IOP) measurements at 1000, 1200 and 1400 h while on timolol treatment. Patients showing at least a 20% IOP reduction on timolol were randomised to 3 months of therapy with DTFC or BTFC, and then were crossed over to the opposite therapy.

Results

Sixty POAG patients completed the study. The mean 24-hour IOP was significantly reduced with both the fixed combinations compared with the timolol-treated diurnal IOP (P<0.001). When the two fixed combinations were compared directly, DTFC demonstrated a lower mean 24-hour IOP level as compared with BTFC (mean difference: −0.7 mm Hg, 95% confidence interval (CI): (−1.0, −0.3), P<0.001). At two individual time points, DTFC significantly reduced IOP more than BTFC: at 1800 h (−1.0 mm Hg, 95% CI (−1.6,−0.5), P=0.001) and at 0200 (−0.9 mm Hg, 95% CI: (−1.4,−0.5), P=0.001). No significant difference existed for the other time points.

Conclusion

Both the fixed combinations significantly reduce 24-hour IOP in POAG. DTFC provided significantly better 24-hour efficacy.     

Increased intraocular pressure on the first postoperative day following resident-performed cataract surgery

Purpose

The aim of this study was to investigate the incidence of intraocular pressure (IOP) elevation after resident-performed cataract surgery and to determine variables, which influence postoperative day 1 (POD1) IOP.

Methods

In all, 1111 consecutive cataract surgeries performed only by training residents between 1 July 2001 and 30 June 2006 were included. Elevated IOP was defined as ≥23 mm Hg. Surgeries were classified according to the presence of POD1-IOP elevation. Fisher''s exact test and Student t-test were used to compare both groups. Multivariate analyses using generalized estimating equations were performed to investigate predictor variables associated with POD1-IOP elevation.

Results

The average preoperative IOP was 16.0±3.2 mm Hg and the average POD1-IOP was 19.3±7.1 mm Hg, reflecting a significant increase in IOP (P<0.001, paired t-test). The incidence of POD1-IOP elevation ≥23 mm Hg was 22.0% (244/1111). Presence of glaucoma and ocular hypertension, higher preoperative IOP, and longer axial length were frequently encountered variables in the POD1-IOP elevation group (all P<0.05). Using a multivariate analysis, presence of glaucoma (P=0.004, OR=2.38; 95% confidence interval (95% CI)=1.31–4.30), presence of ocular hypertension (P=0.003, OR=6.09; 95% CI=1.81–20.47), higher preoperative IOP (P<0.001, OR=3.73; 95% CI=1.92–7.25), and longer axial length (P=0.01, OR=1.15; 95% CI=1.03–1.29) were significant predictive factors for POD1-IOP elevation.

Conclusions

IOP elevation on the first postoperative day following resident-performed cataract surgery occurred frequently (22.0%). Increased early postoperative IOP was associated with presence of glaucoma and ocular hypertension, higher preoperative IOP, and longer axial length.     

Prevalence of pinguecula and pterygium in a general population in Spain

Purpose

To determine the prevalence of pinguecula and pterygium and to investigate their associations in a general adult population in North-Western Spain.

Methods

An age-stratified random sample of 1155 subjects ≥40 years was selected in O Salnés (Spain). From 937 eligible subjects, 619 (66.1%) participated (mean age (SD): 63.4 (14.5) years, range: 40–96 years, 37.0% males). An interview to collect history of systemic diseases and lifestyle details and a comprehensive ophthalmic evaluation in which pinguecula and pterygium were recorded was carried out. The prevalence of pinguecula and pterygium and their relationship with lifestyle factors and ocular and systemic diseases was investigated.

Results

The prevalence of pinguecula was 47.9% (95% confidence interval (CI): 43.9–51.9). This prevalence increased significantly with aging (P=0.002) and was higher in men (56.4% 95% CI: 50.0–62.7) than in women (42.7% 95% CI: 37.8–47.8) (P=0.001). The prevalence of pterygium was 5.9% (95% CI: 4.3–7.9). This prevalence also increased significantly with aging (P=0.005) and was 4.8% (95% CI: 2.6–8.4) in men and 6.5% (95% CI: 4.5–9.3) in women (P=0.346). After controlling for age and sex, pinguecula was associated with alcohol intake (adjusted odds ratio (OR_a): 3.08; 95% CI: 1.60–5.95), pterygium with fluorescein staining (OR_a: 2.64; 95% CI: 1.08–6.46) and both disorders with outer activity (OR_a: 2.07; 95% CI: 1.36–3.15 and 2.28; 95% CI: 1.04–4.98, respectively).

Conclusions

Pinguecula is far more common than pterygium. Alcohol consumption is strongly associated with pinguecula. Fluorescein staining is highly prevalent in subjects with pterygium. Both disorders increase with age and are associated with outer activity.     

The prevalence of ocular complications in leprosy patients seen in the United Kingdom over a period of 21 years

Objective

The objective of this study was to determine the prevalence of ocular complications and blindness among leprosy patients presenting in the United Kingdom.

Methods

Observational prospective study.

Results

A total of 126 consecutive leprosy patients attending their ophthalmic visit were examined, out of which 18 patients were blind in one eye (14.3%) and five patients were blind in both the eyes (4.0%). Visual acuity of ⩾6/18 was present in 96 patients (76.2%). A total of 65 patients (51.6%) had an ocular complication and 28 patients (22.2%) had a sight-threatening leprosy complication (lagophthalmos, severe corneal, or iris disease). The most common ocular complications were impaired lid closure (24 patients, 19%), impaired corneal sensation (20 patients, 15.9%), cataract (20 patients, 15.9%), mild corneal opacity (17 patients, 13.5%), and iris atrophy (17 patients, 13.5%). Impaired corneal sensation was associated with vision <6/18 (P<0.001, OR 13.5, 95% CI 5.14–35.44) and vision <3/60 (P=0.01 OR 6.42, 95% CI 2.15–19.15). Impaired lid closure was significantly associated with increasing age (P=0.029, OR 1.039, 95% CI 1.0–1.08) and vision <3/60 (P=0.03, OR 6.06, 95% CI 1.81–20.24).

Conclusion

There is a significant rate of ocular complications and blindness seen in leprosy patients in the United Kingdom, and over one in five had a potentially sight-threatening ocular complication. Health professionals and all leprosy patients, including those cured of the disease, need to be aware that new eye symptoms and signs require prompt ophthalmology review to prevent avoidable blindness, due to the life-long risk of sight-threatening ocular complications.     

Association between corneal biomechanical properties and myopia in Chinese subjects

Purpose

To examine the relationship between corneal biomechanical properties and the degree of myopia.

Methods

Chinese subjects (n=172, age: 11−65 years) were divided into diagnostic groups with non-myopia (spherical equivalence (SE)>−0.50 D), low (−3.00≤SE≤−0.50 D), moderate (−6.00≤SE<−3.00 D), and high myopia (SE<−6.00 D). Only the right eye of each subject was analyzed. Central corneal thickness (CCT) was measured by optical coherence tomography. An ocular response analyzer was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), intraocular pressure (IOP), and corneal compensated IOP (IOPcc). Refraction was measured by both automated and subjective refractometry and expressed as SE.

Results

CH was significantly lower in high myopia compared with both low and non-myopia (P≤0.002). CCT was 1.5 times more correlated to CH variation compared with refraction. Similarly, CRF was four times more dependent on CCT than refraction. CH (P<0.001) or CRF (P=0.005) was positively correlated to refraction. Both IOP and IOPcc were negatively correlated to refraction (P<0.001), respectively.

Conclusions

CH decreases only in high myopia. Refraction is positively correlated to both CH and CRF but negatively correlated to both IOP and IOPcc. These results indicate that the mechanical strength in anterior segment of the eye is compromised in high myopia. In addition, high myopia may increase the risk of glaucoma.     

Oxidative stress-elevated high gamma glutamyl transferase levels, and aging, intake of tropical food plants, migration and visual disability in Central Africans

AIM: To investigate the independent pathogenic role of high serum gamma-glutamyl transferase (GGT) levels, sociodemographic data, dietary and environmental risk factors for visual disability (VD). METHODS: This was a case-control study, run in 200 black Congolese patients managed in Saint Joseph Hospital Ophthalmology Division from Kinshasa town. Logistic regression model was used to identify determinants of VD (n=58) among sex, age, cigarette smoking, alcohol abuse, rural-urban migration, education levels, aging ≥60 years, intake of red Beans, Safou fruit and Taro leaves, lipid profile, residence, socioeconomic status, and GGT. RESULTS: After adjusting for confounding factors, we identified migration (OR=3.7 95% CI: 1.2-11.3; P=0.023), low education level (OR=3.1 95% CI 1.1-8.5; P=0.026), no intake of Safou fruit (OR=34.2 95% CI 11.5-102; P<0.0001), age ≥ 60 years (OR=2.5 95% CI 1.01-6.5; P=0.049), and serum GGT ≥10 U/L (OR=3.6 95% CI 1.3-9.6; P=0.012) as the significant and independent determinants of VD. CONCLUSION: VD appears as a major public health problem in Central Africa to be prevented or delayed by control of migration, lifestyle changes, antioxidant supplements, appropriate diet, nutrition education, and blocking of oxidative stress.     

Biometric and refractive changes after orbital decompression in Korean patients with thyroid-associated orbitopathy

Purpose

To determine the biometric and refractive changes after orbital decompression in Korean patients with thyroid-associated orbitopathy (TAO).

Methods

Retrospective, observational study (between October 2012 and September 2014) was performed. Patients with TAO undergoing orbital decompression for stable proptosis received ophthalmic examinations, including Hertel exophthalmometry, A-scan biometry, autorefraction measures, corneal topography, and wavefront aberration measures, before orbital decompression and again 2 months after surgery.

Results

Included in the study were 43 eyes from 23 patients. The mean exophthalmometric value decreased by 4.1 mm 2 months after orbital decompression (P<0.001). On average, axial length (AL) increased significantly by 0.08 mm (P<0.001); specifically, 37 (86%) of the 43 eyes had increased AL. Whereas anterior chamber depth and lens thickness showed no significant changes (P=0.086 and P=0.905, respectively), the mean spherical refraction and spherical equivalent (SE) decreased by 0.35 and 0.48 D, respectively (P=0.008 and P<0.001, respectively). However, cylindrical refraction and axis showed no significant changes (P=0.057 and P=0.218, respectively). The changes in AL and SE were significantly correlated (R=−0.411, P=0.009). Notably, there were no changes in corneal topography or wavefront aberration after orbital decompression.

Conclusions

TAO patients who underwent orbital decompression showed myopic refractive change via increase in AL. Possible refractive changes should be considered in cases of TAO complaining of decreased visual acuity after orbital decompression.     

Comparison of Scheimpflug imaging and spectral domain anterior segment optical coherence tomography for detection of narrow anterior chamber angles

Purpose

To compare the performance of anterior chamber volume (ACV) and anterior chamber depth (ACD) obtained using Scheimpflug imaging with angle opening distance (AOD500) and trabecular-iris space area (TISA500) obtained using spectral domain anterior segment optical coherence tomography (SD-ASOCT) in detecting narrow angles classified using gonioscopy.

Methods

In this prospective, cross-sectional observational study, 265 eyes of 265 consecutive patients underwent sequential Scheimpflug imaging, SD-ASOCT imaging, and gonioscopy. Correlations between gonioscopy grading, ACV, ACD, AOD500, and TISA500 were evaluated. Area under receiver operating characteristic curve (AUC), sensitivity, specificity, and likelihood ratios (LRs) were calculated to assess the performance of ACV, ACD, AOD500, and TISA500 in detecting narrow angles (defined as Shaffer grade ≤1 in all quadrants). SD-ASOCT images were obtained at the nasal and temporal quadrants only.

Results

Twenty-eight eyes (10.6%) were classified as narrow angles on gonioscopy. ACV correlated with gonioscopy grading (P<0.001) for temporal (r=0.204), superior (r=0.251), nasal (r=0.213), and inferior (r=0.236) quadrants. ACV correlated with TISA500 for nasal (r=0.135, P=0.029) and temporal (P=0.160, P=0.009) quadrants and also with AOD500 for nasal (r=0.498, P<0.001) and temporal (r=0.517, P<0.001) quadrants. For detection of narrow angles, ACV (AUC=0.935; 95% confidence interval (CI) =0.898–0.961) performed similar to ACD (AUC=0.88, P=0.06) and significantly better than AOD500 nasal (AUC=0.761, P=0.001), AOD500 temporal (AUC=0.808, P<0.001), TISA500 nasal (AUC=0.756, P<0.001), and TISA500 temporal (AUC=0.738, P<0.001). Using a cutoff of 113 mm³, ACV had 90% sensitivity and 88% specificity for detecting narrow angles. Positive and negative LRs for ACV were 8.63 (95% CI=7.4–10.0) and 0.11 (95% CI=0.03–0.4), respectively.

Conclusions

ACV measurements using Scheimpflug imaging outperformed AOD500 and TISA500 using SD-ASOCT for detecting narrow angles.     

Pilot randomised controlled trial of face-down positioning following macular hole surgery

Objective

This was a pilot randomised controlled trial (RCT) to investigate the effect of post-operative face-down positioning on the outcome of macular hole surgery and to inform the design of a larger definitive study.

Methods

In all, 30 phakic eyes of 30 subjects with idiopathic full-thickness macular holes underwent vitrectomy with dye-assisted peeling of the ILM and 14% perfluoropropane gas. Subjects were randomly allocated to posture face down for 10 days (posturing group) or to avoid a face-up position only (non-posturing group). The primary outcome was anatomical hole closure.

Results

Macular holes closed in 14 of 15 eyes (93.3% 95% confidence interval (CI) 68–100%) in the posturing group and in 9 of 15 (60% 95% CI 32–84%) in the non-posturing group. In a subgroup analysis of outcome according to macular hole size, all holes smaller than 400 μm closed regardless of posturing (100%). In contrast, holes larger than 400 μm closed in 10 of 11 eyes (91% 95% CI 58–99%) in the posturing group and in only 4 of 10 eyes (40% 95% CI 12–74%) in the non-posturing group (Fisher''s exact test P=0.02).

Conclusion

Post-operative face-down positioning may improve the likelihood of macular hole closure, particularly for holes larger than 400 μm. These results support the case for a RCT.     

Multifocal electroretinogram in non-pathological myopic subjects: correlation with optical coherence tomography

AIM: To investigate the changes of retinal function in non-pathological myopic subjects using multifocal electroretinography (mfERG) and to correlate the data with the central macular thickness obtained using optical coherence tomography (OCT). METHODS: One hundred and thirteen subjects (113 eyes) with age range from 18 to 35y were enrolled in the study. The subjects were divided into four groups according to spherical equivalent (SE) and axial length (AL): emmetropia group (EG, n=31; SE: +0.75 to -0.50 D; AL: 22 to 24 mm), low and medium myopia group (LMMG, n=26; SE: ＞-0.50 to -6.00 D; AL: ＞24 to 26 mm), high myopia group (HMG, n=34; SE: ＞-6.00 to -10.00 D; AL: ＞26 to 28 mm) and super high myopia group (SHMG, n=22; SE: ＞-10.00 D; AL:＞28 mm). The P1 amplitude density, P1 amplitude, and P1 implicit time of the first-order kernel mfERG responses were obtained and grouped into five rings. The central subfield macular thickness (CST) was obtained using macular cube 512×218 scan of Cirrus HD-OCT. RESULTS: With the increasing of eccentricity, the first positive peak (P1) amplitude density (P=0.0000, 0.0001, 0.0021 in ring 1-3 respectively) and P1 amplitude (all P=0.0000 in ring 1-5) of each group decreased. With the increasing of myopia, P1 implicit time gradually extended (all P=0.0000 in ring 1-3). The average CST in four diagnostic groups was 241.56±12.72 μm, 244.56±12.19 μm, 254.33±11.61 μm, 261.75±11.83 μm respectively. With the increasing of myopia, CST increased (P<0.001). There was negative relationship between CST and P1 amplitude, P1 amplitude density (r=-0.402, P<0.001; r=-0.261, P=0.003). There was positive relationship between CST and P1 implicit time (r=0.34, P<0.001). CONCLUSION: With the increasing of myopia, P1 amplitude density and P1 amplitude of the first-order reaction gradually reduced. This showed potential decline in retinal function in myopia. To some extent it may reflect the functional disorder or depression of the visual cells. The exact mechanism needs further study.     

Reproducibility and agreement in evaluating retinal nerve fibre layer thickness between Stratus and Spectralis OCT

Purpose

To evaluate intra-device reproducibility of retinal nerve fibre layer (RNFL) measurements obtained using Stratus and Spectralis optical coherence tomography, and to analyze inter-device correlation and agreement for these measurements.

Design

Prospective observational study.

Methods

A total of 30 normal individuals participated in the study. One eye of each participant was scanned three times during one session by the same operator using Spectralis and Stratus. Intra-class correlation coefficients (ICCs), correlation coefficients (R), and Bland–Altman plots (BAPs) were used to assess reproducibility, correlation, and agreement between the two devices, respectively.

Results

A significant difference in mean RNFL thickness was seen between Stratus and Spectralis (106.2±6.9 μm vs100.0±7.3 μm, P=0.0001). ICCs of RNFL thickness measurements ranged from 0.69 (clock hour 2; 95% confidence interval (95% CI): 0.54, 0.85) to 0.91 (inferior quadrant; 95% CI: 0.86, 0.96) for Stratus and were higher for Spectralis, ranging from 0.87 (temporal-superior sector; 95% CI: 0.79, 0.94) to 0.96 (global and nasal-inferior sector; 95% CI: 0.94, 0.99). Rs of RNFL thickness measurements between the two instruments ranged from 0.61 (temporal quadrant) to 0.87 (superior quadrant). BAPs demonstrated a systematic difference in RNFL values between the two devices, with Spectralis producing thinner RNFL values than Stratus.

Conclusions

Spectralis demonstrated higher ICCs and thinner RNFL measurements than Stratus. Although the inter-device correlation was good, differences in RNFL measurements obtained by the two devices indicate that these measurements would not be interchangeable in clinical evaluations.     

Reconsidering the connection between vitamin D levels and age-related macular degeneration

Purpose

Recent evidence has suggested a correlation between reduced vitamin D levels and delayed angiogenesis and reduced inflammatory response, which are known to have a major role in the development and progression of age-related macular degeneration (AMD).

Design

Cross-sectional study.

Participants

Members of the Maccabi Healthcare Services (MHS, one of the four largest Israeli Health Maintenance Organization) aged ≥60 years, whose vitamin D levels were taken as part of routine examinations between 2000 and 2008.

Methods

All data for this study were obtained from MHS databases that include medical information on 1.8 million subscribers.

Main outcome measures

Serum 25-OH vitamin D levels.

Results

The total study population comprised of 1045 members diagnosed as having AMD, and 8124 as non-AMD, for whom there was information on vitamin D levels. The mean±SD level of 25-OH vitamin D was 24.1±9.41 ng/ml (range 0.8–120) for the AMD patients and 24.13±9.50 ng/ml (range 0.0–120) for the controls (P=ns). One-third (33.6%) of the AMD patients and 32.86% of the controls had a 25-OH vitamin D level <16 ng/ml, and the proportions of tests in which the 25-OH vitamin D level was >74 ng/ml were 0.19 and 0.14%, respectively (P=ns)

Conclusions

No association was detected between vitamin D levels and the presence of AMD in this cross-sectional study. These results raise some doubt about an association between reduced vitamin D levels and the prevalence of AMD.     

Photopsias are related in part to perceived stress and positive mood in retinitis pigmentosa

Purpose

We measured the relationship between the occurrence of photopsias (spontaneous phosphenes), and retinitis pigmentosa (RP) subjects'' level of vision, light exposure, and psychosocial factors to attempt to confirm RP patients'' previous reports of these associations.

Methods

A total of 36 RP subjects self-administered PC-based binocular visual acuity, contrast sensitivity, and visual field tests at home twice a week, for 16 sessions in 2–3 months. After each session, subjects reported photopsias during the vision tests and completed questionnaires: Epworth Sleepiness Scale, Stanford Sleepiness Scale, Perceived Stress Scale, and Positive and Negative Affect Schedules.

Results

Across all subjects, photopsias occurred during 47% of sessions. Five (14%) subjects never noted photopsias, while five others noted photopsias at every session. Two-thirds of subjects experienced photopsias frequently (>20% of sessions). On average, the odds of noticing photopsias increased by 57% for every 1-point increase in mean perceived stress (OR=1.57; 95% CI: 1.04, 2.4; P=0.03) or reduced by 38% for every 1-point increase in positive mood (OR=0.62; 95% CI: 0.39, 0.98; P=0.04), after adjusting for age, gender, and vision. Similarly, the odds of experiencing photopsias during a session increased by 16% for every 3-point increase in perceived stress and decreased by 17% for every 3-point increase in positive mood, after adjusting for age and gender (OR=1.16; 95% CI: 1.01, 1.33; P=0.048)(OR=0.83; 95% CI: 0.73, 0.94; P=0.004), respectively. Frequency of photopsias was not statistically significantly related to other factors measured.

Conclusions

Increased photopsias appear to be related to times when subjects report increased perceived stress and/or decreased positive mood, rather than RP patients'' age, level of vision, reported light exposure, or sleepiness.     

The association between respiratory tract Ureaplasma urealyticum colonization and severe retinopathy of prematurity in preterm infants ≤1250 g

Aim

To evaluate the association between respiratory tract Ureaplasma urealyticum (Uu) colonization and development of retinopathy of prematurity (ROP) requiring treatment.

Methods

The infants with birthweight (BW) ≤1250 g born in a third-level neonatal intensive care unit between March 2009 and May 2010 were prospectively identified. Nasopharyngeal swabs for Uu colonization were taken in postnatal first 3 days. Culture-positive patients were reevaluated on the twelfth day by nasopharyngeal swabs for Uu. The primary outcome was to define whether there was an association between respiratory tract Uu colonization and severe ROP requiring treatment. Independent sample''s t-test or Mann–Whitney U-test was used to compare continuous variables and Chi-square test or Fisher''s exact test for categorical variables. Multivariate (backward) logistic regression analysis was performed to simultaneously measure the influence of the independent variables with ROP as the dependent variable.

Results

A total of 25 (12.1%) infants developed severe ROP requiring treatment among 206 infants who underwent ROP screening. Mean BW and gestational age of total cohort were 1013±159 g and 27.9±1.6 weeks, respectively. Multivariate analysis demonstrated that BW (OR: 0.64 (95% Cl 0.47–0.88); P=0.006), duration of mechanical ventilation (OR: 1.17 (95% Cl 1.06–1.28); P=0.001), premature rupture of membrane >18 h (OR: 3.83 (95% Cl 1.2–12.2); P=0.02), and Uu positivity in both cultures (OR: 5.02 (95% Cl 1.8–13.9); P=0.002) were independent risk factors for the development of severe ROP requiring treatment.

Conclusions

Respiratory tract colonization with Uu was independently associated with severe ROP requiring treatment.     

The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery: report 2, relationships of axial length with ocular copathology,preoperative visual acuity,and posterior capsule rupture

Purpose

To describe the relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture rates in patients undergoing cataract surgery.

Design

The Royal College of Ophthalmologists'' National Ophthalmology Database (NOD) study.

Methods

Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Data parameters included: demographics, biometry, ocular copathology, visual acuity measurements, and surgical complications including posterior capsule rupture, or vitreous loss or both (PCR).

Results

Consultant surgeons performed a higher proportion of operations on eyes whose axial length were at the extremes. Glaucoma and age related macular degeneration were more common in eyes with shorter axial lengths, whilst previous vitrectomy was associated with longer axial lengths. Eyes with brunescent or white cataracts or amblyopia were more common at both axial length extremes. Preoperative visual acuities were similar for eyes with axial length measurements up to approximately 28 mm and worse for eyes with longer axial length measurements. PCR rates showed little change with axial length (overall mean 1.95%, 95% CI: 1.89 to 2.01%), except for a borderline increase in eyes with axial length <20.0 mm where rates were 3.6% (95% CI: 2.0 to 6.3%). The likelihood of PCR in eyes with axial length <20.0 mm was 1.88 times higher than those of ≥20.0 mm (P=0.0373).

Conclusion

Rates of ocular comorbidities vary by axial length. PCR rates in eyes with very short or long axial lengths were lower than expected.     

Visual outcome in Japanese patients with Acanthamoeba keratitis

Purpose

To identify prognostic factors affecting visual outcome in Acanthamoeba keratitis (AK) treated with topical chlorhexidine gluconate (CHG).

Methods

A total of 35 eyes in 34 patients with AK were treated with 0.02% topical CHG. Patients were divided into two groups according to the final visual outcome: Group 1, final visual acuity (VA) of 20/25 or greater (22 eyes); Group 2, less than 20/25 (13 eyes). We compared these groups and evaluated the effectiveness of topical CHG compared with outcomes in previous reports.

Results

Ring infiltrate was observed more often in Group 2 (4.5% vs 61.5%, OR 33.6, 95% confidence interval (CI) 3.4–333.9, P<0.01). The duration between onset and diagnosis of AK was significantly longer (24.9 days vs 48.4 days, OR 1.03, 95% CI 1.00–1.06, P=0.04) and VA at initial examination (log MAR) significantly lower (0.47 vs 1.59, OR 25.5, 95% CI 3.4–186.7, P<0.01) in Group 2 (visual outcome <20/25). Multivariate analysis revealed that only VA at initial examination was independently associated with worse visual outcome (adjusted OR 24.5, 95% CI 1.9–312.6, P=0.01). Seventeen (85.0%) of the 20 eyes diagnosed within 1 month and 24 (82.8%) of 29 eyes diagnosed within 2 months achieved a VA of 20/40 or greater.

Conclusion

VA at initial examination was the most predictive factors for final visual outcome in AK. Topical CHG was comparably effective to other treatments, including polyhexamethyl biguanide and propamidine isethionate.     

Interferon-gamma release assay as a diagnostic test for tuberculosis-associated uveitis

Background

To study the use of interferon-gamma release assay (IFN-γ) (IGRAs) as a diagnostic test for tuberculosis (TB)-associated uveitis (TAU).

Design

Prospective cohort study.

Participants

Consecutive new patients (n=162) with clinical ocular signs suggestive of TAU, seen >1 year period at a single tertiary center.

Methods

All subjects underwent investigations to rule out underlying disease, including T-SPOT.TB and tuberculin skin test (TST). Twenty-one subjects with underlying disease and three with interdeterminate T-SPOT.TB results were excluded. Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation. Anti-TB therapy (ATT) was prescribed if required. Patients'' treatment response and recurrence were monitored for six months after completion of ATT, if given; or 1 year if no ATT was given.

Main outcome measure

Diagnosis of TAU.

Results

Mean age of study cohort (n=138) was 46.8±15.3 years. Majority were Chinese (n=80, 58.0%) and female (n=75, 54.3%). TST was more sensitive than T-SPOT.TB (72.0% vs36.0%); but T-SPOT.TB was more specific (75.0% vs51.1%) for diagnosing TAU. Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86–2.42) or TST (1.47; 95% CI, 1.12–1.94)-positive result are more likely to have TAU. The accuracy of diagnosing TAU increases when both tests are used in combination (area under the receiver operator curve=0.665; 95% CI, 0.533–0.795). Patients with both tests positive are 2.16 (95% CI, 1.23–3.80) times more likely to have TAU. Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).

Conclusions

We recommend using a combination of clinical signs, IGRA, and TST to diagnose TAU.     

Heritability of the spatial distribution and peak density of macular pigment: a classical twin study

Purpose

To elucidate the heritability of peak density and spatial width of macular pigment (MP) using a Classical Twin Study.

Methods

Fundus autofluorescence images were obtained at 488 nm from 86 subjects or 43 twin pairs (21 monozygotic (MZ) and 22 dizygotic (DZ)) (27 male, 59 female) aged from 55 to 76 years (mean 62.2±5.3 years). The relative topographic distribution of MP was measured using a grey scale of intensity (0–255 units) in a 7° eccentricity around the fovea. Relative peak MP density (rPMPD) and relative spatial distribution of MP (rSDMP) were used as the main outcome measure in the statistical analysis.

Results

A significantly higher correlation was found within MZ pairs as compared with that within DZ pairs for rPMPD, (r=0.99, 95% confidence interval (95% CI) 0.93 to 1.00) and 0.22, 95% CI −0.34 to 0.71), respectively, suggesting strong heritability of this trait. When rSDMP was compared, there was no significant difference between the correlations within MZ pairs (r=0.48, 95% CI −0.02 to 0.83) and DZ pairs (r=0.63, 95% CI 0.32 to 0.83), thus rSDMP is unlikely to have a considerable heritable component. In addition, there was no difference between any MP parameter when normal maculae were compared with early age-related macular degeneration (AMD) (rPMPD 0.36 vs 0.34, t=1.18 P=0.243, rSDMP 1.75 vs 1.75, t=0.028 P=0.977).

Conclusions

rPMPD is a strongly heritable trait whereas rSDMP has minimal genetic influence and a greater influence by environmental factors. The presence of macular changes associated with early AMD did not appear to influence any of these pigment parameters.     

Prevalence and risk factors for primary open-angle glaucoma in a rural northeast China population: a population-based survey in Bin County, Harbin

Purpose

To estimate the prevalence and associated risk factors of primary open-angle glaucoma (POAG) in a rural population in northeast China.

Methods

A population-based survey was conducted within Bin County, Harbin of northeast China. Glaucoma was diagnosed using International Society of Geographical and Epidemiological Ophthalmology criteria. All the subjects underwent a complete ophthalmic examination.

Results

A total of 4956 (86.0%) of 5762 subjects aged 40 years or older were examined. The mean intraocular pressure (IOP) of right eyes was 14.0 (95% confidence interval (CI), 13.9 to 14.1) mm Hg. The prevalence of POAG was 0.71% (35/4956, 95% CI, 0.47 to 0.93). In these POAG subjects, 17 (48.6%) had elevated IOP >21 mm Hg in either eye, 3 (8.8%) participants had been treated by laser trabeculoplasty or trabeculectomy and were known to have POAG. Vision impairment to varying degrees was present in 20 subjects (58.8%) with 1 subject blind in both eyes and 8 subjects blind in one eye. On multivariate analysis, age, family history of glaucoma, systemic hypertension, and IOP were regarded as significant independent risk factors.

Conclusions

POAG is a disease of serious consequence and of low diagnosis and treatment rates in rural northeast China. Age, family history of glaucoma, systemic hypertension, and IOP remain as significant independent risk factors for POAG.     

Differences in uveal melanomas between men and women from the British Isles

Purpose

The purpose of this study is to compare uveal melanomas (UMs) in men and women.

Methods

The Liverpool Ocular Oncology Centre (LOOC) database was reviewed. Patients treated for UM at the LOOC between 1993 and 2010 were selected. Differences between sexes were identified using the χ ²-test for categorical variables and the Mann–Whitney test for continuous variables.

Results

The 3380 patients comprised 1685 women and 1695 men. The tumours were considered clinically to have arisen in choroid in 89.5%, ciliary body in 5.3%, and iris in 5.2%. Tumours in women were less likely to originate in choroid (87.2 vs91.7% P<0.001) and showed more circumferential spread in ciliary body (P<0.001) and iris (P=0.003). Tumours in men were more likely to extend to within 3 mm of optic disc or fovea (46.3 vs39.0%, P<0.001), showing more extensive optic-disc involvement (P<0.001). The median largest basal tumour diameter was 12.2 mm in men and 11.9 mm in women (P=0.001). The tumour thickness had a median of 4.4 mm and 3.8 mm in men and women, respectively (P=0.015). The 180 ciliary body tumours occurred in 112 women and 68 men. In these, the prevalence of extraocular spread was higher in women (19.6 vs8.8% P=0.052). The 175 iris melanomas were more common in women than men (103 vs72, respectively).

Conclusions

In men, UMs tend to be larger and more posterior than in women.