Flavio E. Hirai

Assessing Efficacy of Combined Riboflavin and UV-A Light (365 nm) Treatment of Acanthamoeba Trophozoites

PURPOSE To assess the Acanthamoeba trophozoite viability in vitro and treatment of Acanthamoeba keratitis in a hamster model using ultraviolet light A (UV-A) and riboflavin (B2). METHODS A sample of Acanthamoeba sp. cultured was transferred to a 96-well plate and exposed to B2 and the UV-A light (365 nm wavelength) at a power density of 3 mW/cm(2), 8 mm spot diameter, for 30 minutes. The exposure was done in triplicate. Control groups were prepared in triplicate as well: blank control, UV-A only, riboflavin only, and dead control. Cell viability assessment was done using the trypan blue dye exclusion method. Acanthamoeba keratitis was induced in Chinese hamsters; who were randomly assigned to one of the animal groups: UV-A + B2, propamidine isethionate (Brolene; Sanofi-Aventis, Ellerslie, Auckland, Australia), UV-A + B2 + propamidine isethionate (Brolene), only UV-A, only B2, and blank. Throughout the 14 days after treatment the animals were examined clinically. Histology and clinical scores of all groups were compared. RESULTS The in vitro study showed no difference between the treatment group UV-A + B2 and the control groups. In the hamster keratitis model a significant improvement of clinical score was observed for the groups propamidine isethionate (Brolene) and UV-A + B2 + propamidine isethionate (Brolene) (P = 0.0067). Also a significant worsening of clinical score was observed in the other groups: UV-A + B2 group (P = 0.0084), only UV-A (P = 0.0078), B2 only (P = 0.0084), and blank (P = 0.0082). No difference was observed between propamidine isethionate (Brolene) and UV-A + B2 + propamidine isethionate (Brolene). CONCLUSIONS The adjunctive use of UV-A and B2 therapy did not demonstrate antitrophozoite activity; in vivo UV-A and B2 did not demonstrate efficacy in this model.

Micropulse diode laser treatment for chronic central serous chorioretinopathy: a randomized pilot trial.

BACKGROUND AND OBJECTIVE To evaluate 810-nm subthreshold diode micropulse (SDM) laser in patients with chronic central serous chorioretinopathy (CSC). PATIENTS AND METHODS Prospective, randomized, double-blind, sham-controlled pilot trial. Patients were randomized to SDM laser treatment (group 1) or sham procedure (group 2). Primary outcome measure was change in best corrected visual acuity (BCVA); secondary outcome was central macular thickness after 3 months. Laser treatment was performed along the detached area. At the 3-month visit, all patients were evaluated for re-treatment if they met re-treatment criteria. RESULTS Fifteen patients were included in this study: five patients in the sham group and 10 in the treatment group. At 3 months, BCVA was significantly enhanced in the treatment group (P = .006) compared with the sham group (P = .498). All patients from the sham group needed treatment after 3 months. An improvement in central macular thickness and leakage on fluorescein angiography was noted in all treated patients (in both groups). CONCLUSION In this limited-size, short-term exploratory study, SDM laser was effective in treating chronic CSC. There was no evidence of retinal damage induced by treatment.

Relationship of Glycemic Control, Exogenous Insulin, and C-Peptide Levels to Ischemic Heart Disease Mortality Over a 16-Year Period in People With Older-Onset Diabetes The Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR)

OBJECTIVE—The purpose of this study was to examine the relationship of glycemic control and exogenous and endogenous insulin levels with all-cause and cause-specific mortality (ischemic heart disease and stroke) in an older-onset diabetic population. RESEARCH DESIGN AND METHODS—The Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) is an ongoing, prospective, population-based cohort study of individuals with diabetes first examined in 1980–1982. A stratified sample of all individuals with diabetes diagnosed at 30 years of age or older was labeled “older-onset” (n = 1,370). Those participating in the 1984–1986 examination phase (n = 1,007) were included in the analysis. Endogenous insulin was determined by measurements of plasma C-peptide (in nanomoles per liter), and exogenous insulin was calculated in units per kilogram per day. Glycemic control was determined by levels of glycosylated hemoglobin (HbA1). RESULTS—After 16 years of follow-up, 824 individuals died (all-cause mortality); 358 deaths involved ischemic heart disease and 137 involved stroke. C-peptide and HbA1 were significantly associated with all-cause and ischemic heart disease mortality in our study. The hazard ratio (95% CI) values for all-cause mortality were 1.12 (1.07–1.17) per 1% increase in HbA1, 1.20 (0.85–1.69) per 1 unit · kg−1 · day−1 increase in exogenous insulin, and 1.15 (1.04–1.29) per 1 nmol/l increase in C-peptide and for ischemic heart disease mortality were 1.14 (1.06–1.22), 1.50 (0.92–2.46), and 1.19 (1.02–1.39) for HbA1, exogenous insulin, and C-peptide, respectively, after adjusting for relevant confounders. C-peptide was associated with stroke mortality only among men (1.65 [1.07–2.53]). CONCLUSIONS—Our results show that individuals with higher endogenous insulin levels are at higher risk of all-cause, ischemic heart disease, and stroke mortality.

Prevalence of refractive errors in a Brazilian population: the Botucatu eye study.

Purpose: To determine the prevalence and demographic associations of refractive error in Botucatu, Brazil.Methods: A population-based, cross-sectional prevalence study was conducted, which involved random, household cluster sampling of an urban Brazilian population in Botucatu. There were 3000 individuals aged 1 to 91 years (mean 38.3) who were eligible to participate in the study. Refractive error measurements were obtained by objective refraction.Results: Objective refractive error examinations were performed on 2454 residents within this sample (81.8% of eligible participants). The mean age was 38 years (standard deviation (SD) 20.8 years, Range 1 to 91) and females comprised 57.5% of the study population. Myopia (spherical equivalent (SE) < − 0.5 dropters (D)) was most prevalent among those aged 30–39 years (29.7%; 95% confidence interval (CI) 24.8–35.1) and least prevalent among children under 10 years (3.8%; 95% confidence interval (CI) 1.6–7.3). Conversely hypermetropia (SE > 0.5D) was most prevalent among participants under 10 years (86.9%; 95% CI 81.6–91.1) and least prevalent in the fourth decade (32.5%; 95% CI 28.2–37.0). Participants aged 70 years or older bore the largest burden of astigmatism (cylinder at least −0.5D) and anisometropia (difference in SE of > 0.5D) with a prevalence of 71.7% (95% CI 64.8–78.0) 55.0% (95% CI 47.6–62.2) respectively. Myopia and hypermetropia were significantly associated with age in a bimodal manner (P < 0.001), whereas anisometropia and astigmatism increased in line with age (P < 0.001). Multivariate modeling confirmed age-related risk factors for refractive error and revealed several gender, occupation and ethnic-related risk factors. Conclusions: These results represent previously unreported data on refractive error within this Brazilian population. They signal a need to continue to screen for refractive error within this population and to ensure that people have adequate access to optical correction.

Prevalence and causes of visual impairment in a Brazilian population: The Botucatu Eye Study

BackgroundThis paper reports population-based data on the prevalence and causes of visual impairment among children and adults in Botucatu, Brazil.MethodsA population-based cross-sectional study was conducted involving a random start point and then systematic sampling of an urban Brazilian population in the city of Botucatu. There were approximately 3 300 individuals aged 1 to 91 years who were eligible to participate in the study. Of this sample, 2485 (75.3%) underwent ophthalmic examination. The ophthalmic examination included uncorrected (presenting) and best corrected distance visual acuity using standardized protocols. The primary cause of decreased visual acuity was identified for all patients with visual impairment.ResultsPresenting low vision and presenting blindness were found in 5.2% (95% CI: 4.3–6.1) and 2.2% (95% CI: 1.6–2.8) of the population, respectively. Unilateral presenting low vision and unilateral presenting blindness were found in 8.3% (95% CI: 7.2–9.5) and 3.7% (95% CI: 2.9–4.4) of the population respectively. Best corrected low vision was found in 1.3% of the population (95% CI: 0.9–1.7) and best corrected blindness was discovered in 0.4% of people (95% CI: 0.2–0.7). The main cause of presenting low vision was refractive error (72.3%) and cataract was the most prevalent cause of blindness (50%).ConclusionThe main causes of low vision and blindness in this Brazilian city were uncorrected refractive errors, cataract, and retinal diseases. Programs to further reduce the burden of visual impairment need to be targeted toward the correction of refractive error and surgery for cataracts.

Severe Hypoglycemia and Smoking in a Long-Term Type 1 Diabetic Population: Wisconsin Epidemiologic Study of Diabetic Retinopathy

OBJECTIVE—The purpose of this study was to evaluate the relationship of severe hypoglycemia and smoking in a population-based cohort of individuals with long-term type 1 diabetes. RESEARCH DESIGN AND METHODS—This was a cross-sectional analysis of the population-based cohort of the Wisconsin Epidemiologic Study of Diabetic Retinopathy. The analyses in this report were limited to 537 type 1 diabetic individuals with complete data who participated in the last examination phase (2000–2001). Severe hypoglycemia was defined as having one or more episodes of loss of consciousness or overnight hospitalization attributable to hypoglycemia in a 1-year period before the examination. RESULTS—The prevalence of severe hypoglycemia in this population was 14.3%. In univariate analysis, current smokers had a greater chance of having severe hypoglycemia compared with never smokers (odds ratio 2.40 [95% CI 1.30–4.40]). When we controlled for relevant confounders such as age, sex, A1C, waist-to-hip ratio, orthostatic hypotension, alcohol consumption, intensive insulin treatment, past history of severe hypoglycemia, and late complications of diabetes (nephropathy, neuropathy, and retinopathy), the association remained statistically significant, with current smoking presenting ∼2.6 times greater odds of developing severe hypoglycemia. CONCLUSIONS—Current smokers with type 1 diabetes have higher odds of severe hypoglycemia episodes.

Postural blood pressure changes and associated factors in long-term Type 1 diabetes: Wisconsin Epidemiologic Study of Diabetic Retinopathy

PURPOSE To describe the frequency of orthostatic hypotension and hypertension and associations with risk factors in a cohort of persons with long-term Type 1 diabetes (n=440) participating in the Wisconsin Epidemiologic Study of Diabetic Retinopathy. METHODS Evaluations included detailed medical history, electrocardiography (ECG), and laboratory tests. Blood pressure (BP) was measured in supine and standing positions. Standing decrease in systolic (SBP) or diastolic (DBP) BP of at least 20 or 10 mmHg, respectively, was defined as orthostatic hypotension; increase of SBP from <140 to >or=140 mmHg or DBP from <90 to >or=90 mmHg was defined as orthostatic hypertension. RESULTS Prevalence of orthostatic hypotension and orthostatic hypertension was 16.1% and 15.2%, respectively. Some ECG measurements of cardiac autonomic dysfunction were significantly associated with orthostatic hypotension. Association between SBP and orthostatic hypotension and orthostatic hypertension were significant [odds ratio, 1.02 (95% confidence interval, or CI, 1.01-1.05) and 1.02 (95% CI, 1.01-1.04), per 1 mmHg, respectively] after adjusting for confounders. Interaction between SBP and age was observed. SBP was significantly associated with orthostatic hypotension and orthostatic hypertension in people <or=40 years old [1.35 (1.02-1.78) and 1.12 (1.05-1.18), respectively]. CONCLUSIONS Results showed that measurements derived from the ECG can help describe an individual at increased risk of having postural BP changes. Moreover, SBP was associated with postural BP changes among individuals who were <40 years of age with long-term Type 1 diabetes.

Eye blink in newborn and preschool-age children

Purpose:  To investigate the dynamics of ocular eyelid movements in newborn infants and preschool‐age children.

Prevalence and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus in ocular infections

PURPOSE To study the prevalence of methicillin-resistant Staphylococcus aureus among S. aureus ocular infections in a tertiary health center in Brazil and compare antibiotic susceptibility patterns between MRSA and methicillin-susceptible S. aureus isolates. METHODS Electronic records from the ocular microbiology laboratory of the Universidade Federal de São Paulo were retrospectively reviewed. During a 10-year period (between January 2000 and December 2009) all conjunctivitis, keratitis, and endophthalmitis cases with a positive culture for S. aureus were identified. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method. RESULTS Five hundred sixty-six S. aureus isolates were identified; of those, 56 (9.9%) were resistant to methicillin. Throughout the 10-year period, Staphylococcus aureus showed a significant increasing trend from 7.55% to 16.18% among overall S. aurues infections (p=0.001) and from 3.7% to 13.16% in conjunctivitis (p=0.001). Conversely, we did not observe the same trend among those with keratitis (p=0.38). Staphylococcus aureus isolates showed higher resistance rates to tobramycin, gentamicin, ciprofloxacin, gatifloxacin, and moxifloxacin when compared with S. aureus isolates (p< 0.001). All cases were susceptible to vancomycin. CONCLUSION We observed an increasing trend in the overall prevalence of Staphylococcus aureus ocular infections and statistically significant higher resistance rates to commonly used antibiotics compared to Staphylococcus aureus. Our data supports the need for constant bacterial surveillance and should be taken into consideration before initiating empiric treatment of ocular infections.

Boston type 1 keratoprosthesis outcomes in ocular burns.

Purpose:  To report the outcomes of Boston type I keratoprosthesis (BKPro) in the management of ocular burn injuries.