Influence of diabetes on macular thickness measured using optical coherence tomography: the Singapore Indian Eye Study.

PURPOSE: To determine the influence of diabetes, diabetic retinopathy (DR), and other factors on macular thickness, measured using optical coherence tomography (OCT), in a population-based sample. METHODS: Data from the population-based Singapore Indian Eye Study were analyzed. We measured macular thickness using Stratus OCT Fast Macular Thickness scan protocol in 228 participants with diabetes mellitus (including 167 without DR, 44 with mild DR, 17 with moderate or severe DR) and 72 non-diabetic controls without macular oedema or other macular lesions. Analysis was done on right eyes. RESULTS: The mean age of participants was 60.1 ± 10.1 years, with 53.8% men. Macular thickness measurements did not differ significantly between diabetic participants with no or mild DR and non-diabetic participants. Diabetic participants with moderate or severe DR had greater foveal and temporal outer macula thickness compared with those with no or mild DR (P=0.003). In a multivariate linear regression model, older age (P=0.009), male gender (P=0.005), and lower spherical equivalent (P=0.001) were other factors associated with greater foveal thickness in all participants after controlling for body mass index, glycosylated haemoglobin, total cholesterol, and mean systolic blood pressure. CONCLUSION: This population-based study showed that diabetic participants with moderate or severe DR had thicker foveal measurements, even in the absence of diabetic macula oedema, than non-diabetic controls. Other factors that influenced macular thickness measurements were age, gender, and spherical equivalent. These data may aid the interpretation of OCT findings in persons with diabetes and DR.

Changes in retinal nerve fibre layer, optic nerve head morphology, and visual field after acute primary angle closure.

AIMS/PURPOSE: To determine and correlate the long-term changes in retinal nerve fibre layer (RNFL) thickness, optic nerve head (ONH) morphology, and visual fields after a single episode of acute primary angle closure (APAC). METHODS: This was a cross-sectional comparative study of patients at National University Hospital (Singapore) from 2000 to 2006 after an episode of unilateral APAC. The peripapillary and macular RNFL were measured using Stratus optical coherence tomography (OCT) and ONH configuration was assessed using Heidelberg Retina Tomography (HRT)-III. Humphrey perimetry was also performed, and the presence of disc pallor was noted. APAC eyes were compared with fellow eyes as matched controls. RESULTS: Twenty-five patients were assessed at a median of 33 months (range, 11-85 months) after APAC. OCT showed that there was a reduction in the peripapillary and outer macular RNFL thickness in APAC eyes compared with controls. Humphrey perimetry revealed significantly reduced mean deviation (P=0.006) and increased pattern standard deviation (P=0.045) in APAC eyes compared with controls. HRT-III showed no difference in mean rim area, rim volume, or cup-disc ratio between APAC eyes and controls. Disc pallor was present in nine APAC eyes (36%) but was absent in fellow eyes (P=0.002), and was associated with peripapillary RNFL thinning, visual field loss, and an increased interval between the onset of symptoms and normalization of intraocular pressure (P=0.023). CONCLUSION: APAC results in peripapillary and outer macular RNFL loss, visual field defects, and optic disc pallor, even in cases in which the ONH configuration remains unchanged.

Risk factors for endogenous Klebsiella endophthalmitis in patients with Klebsiella bacteraemia: a case-control study.

AIM: To identify risk factors for Klebsiella endophthalmitis in patients with Klebsiella sepsis. METHODS: This is a retrospective case-control study. The study population consisted of all patients with positive blood cultures for Klebsiella, admitted to Changi General Hospital (Singapore) from August 2004 to July 2005. The cases were patients who developed Klebsiella endophthalmitis, and the controls were those who did not. The potential risk factors analysed included age, sex, race and total white cell count at presentation, maximum temperature response, co-morbid pathologies, presence of severe infection, site of primary infection, antibiotic sensitivity of the bacterial strain, and systemic antibiotics treatment regimen. RESULTS: 133 consecutive patients with Klebsiella bacteraemia confirmed by blood culture were included. Five (3.8%) developed endophthalmitis. Klebsiella endophthalmitis was significantly associated with liver abscess as the primary site of infection (p<0.001) and disseminated intravascular coagulation (p = 0.010) on both univariate and multivariate analysis. Diabetes mellitus and other co-morbid pathologies, race and maximum temperature response were not risk factors for the occurrence of endophthalmitis. CONCLUSIONS: Liver abscess and disseminated intravascular coagulation are risk factors for endogenous endophthalmitis in patients with Klebsiella sepsis.