Letícia Procianoy

Incidence and risk factors for retinopathy of prematurity in very low and in extremely low birth weight infants in a unit-based approach in southern Brazil

AimsTo analyse the incidence and risk factors for retinopathy of prematurity (ROP) and survival rates among extremely low birth weight (ELBW) and very low birth weight (VLBW) preterm infants.MethodsA prospective cohort study of 352 infants admitted at a teaching hospital, Hospital de Clinicas de Porto Alegre, Brazil, between October 2002 and December 2006, was screened for ROP. The ELBW group comprised infants whose birth weight (BW) was ⩽1000 g and the VLBW group comprised those infants whose BW were >1000 g and ⩽1500 g. Perinatal risk factors for ROP were assessed using univariate and multivariate analysis.ResultsOf the 352 neonates screened, 88 were ELBW babies. Survival rates among ELBW and VLBW were 47.8 and 88.7%, respectively. ROP affected 48.9% of ELBW infants and 18.2% of VLBW babies. Threshold disease occurred in 21 patients, 15 of whom were born weighing <1000 g. Only 2.3% of the neonates born with more than 1000 g developed treatable disease. Univariate analysis showed that gestational age (GA), BW, use of indomethacin and erythropoietin, blood transfusions, and intraventricular haemorrhage were associated with ROP. After logistic regression, the most important adjusted risk factors were BW (OR: 1.002;95% CI: 1.001–1.003; P=0.003), GA (OR: 1.254;95% CI: 1.082–1.455; P=0.003), and use of erythropoietin (OR: 2.486;95% CI: 1.182–5.231; P=0.016).ConclusionThis study showed reduced survival rates, high incidence of ROP, and a greater need of treatment among ELBW infants as compared to VLBW babies admitted in this institution.

The accuracy of binocular fixation preference for the diagnosis of strabismic amblyopia

PURPOSE To determine the accuracy of different scales of the binocular fixation preference test and 10(Delta) fixation test in diagnosing amblyopia in patients with strabismus. METHODS A prospective and masked diagnostic study was undertaken. We compared 3 binocular fixation preference test scales with interocular Early Treatment Diabetic Retinopathy Study (ETDRS) acuity differences. The 10(Delta) fixation test was used for patients with strabismus <10(Delta). Sensitivity, specificity, and likelihood ratios for amblyopia with an interocular difference of >or=2 lines were determined. Intra- and interexaminer agreements were measured. RESULTS The study included 221 literate strabismic patients. The accuracy of the binocular fixation preference test was similar for all scales, with no advantage in combining them (Cronbachs alpha = 0.99). The sensitivity and specificity of binocular fixation preference among patients with strabismus >or=10(Delta) were 72.8% (95% CI, 59.7%-83.6%) and 77.6% (95% CI, 66.6%-86.3%), respectively; among patients with deviations <10(Delta), these were 89.6% (95% CI, 72.6%-97.8%) and 64.2% (95% CI, 44.0%-81.3%), respectively. The 10(Delta) fixation test did not alter this accuracy. Likelihood ratios were stronger for extreme grades of the binocular fixation preference test; however, in intermediate grades, they only changed by approximately 15% of the pretest probability of amblyopia. Intra- and interexaminer agreements were 76% (95% CI, 51%-100%) and 73% (95% CI, 48%-97%), respectively. CONCLUSIONS The binocular fixation preference test is more useful for diagnosing amblyopia when the results indicate either a very strong preference or no fixation preference. The intermediate grades of the test were less accurate in our study, accounting for most of the false positives and negatives results.

Uso de levodopa em pacientes com ambliopia

Ambliopia O definida como uma diminuicao da acuidadevisual unilateral (o mais frequente) ou bilateral, decorrente dedeprivacao visual e ou de interacao binocular anormal. Naotem causa orgânica detectAEvel ao exame fisico do olho,ocorrendo no periodo de imaturidade do sistema visual. Ereversivel quando tratada em tempo e de modo apropriado.Diagnostica-se ambliopia quando a diferenca de visao entreos olhos O de duas ou mais linhas ou quando a visao O 20/30 oupior na escala de Snellen.Estrabismo e anisometropia sao as causas mais frequentesde ambliopia, ocorrendo em 2 a 5% da populacao

Resultados do tratamento da ambliopia com levodopa combinada à oclusão

PURPOSE: To evaluate visual acuity improvement with levodopa/benzerazide associated with partial occlusion and followed by total occlusion therapy in patients with amblyopia considered irreversible. METHODS: A 9-week experimental open study was performed involving 37 patients, between 7 and 40 years old, with strabismic and/or anisometropic amblyopia. All patients were treated with levodopa (0.70 mg/kg/day) and 25% benzerazide associated with 4-hour/day occlusion of the dominant eye for 5 weeks. In the last 4 weeks, only the total occlusion (24 h) of the dominant eye was performed. Visual acuity was measured by the Early Treatment Diabetic Retinopathy (ETDR) table with the logarithmic minimum angle of resolution (logMAR) scale before the beginning of the treatment and after 1, 3, 5 and 9 weeks of treatment. Adhesions to occlusion therapy and to drug intake were checked through a written questionnaire and capsule counting. Adverse effects were evaluated by clinical examination and questionnaire. RESULTS: After 9 weeks of treatment visual acuity improved from 0.58 ± 0.16 to 0.23 ± 0.16 logMAR (4 lines of improvement in the ETDR table). CONCLUSION: Levodopa dose of 0.70 mg/kg/day is well tolerated and, when associated with occlusion therapy, significantly improves visual acuity in patients with amblyopia considered irreversible.

Graded anterior transposition of the inferior oblique muscle for V-pattern strabismus

To the Editor: The purpose of the study by Akar and colleagues was to evaluate the efficacy of bilateral graded anterior transposition of the inferior oblique muscle for the correction of V-pattern strabismus associated with inferior oblique overaction. They are to be congratulated for collecting such a large series of patients. However, the authors did not take into account some important points. In their Methods section, the presence of V patterns was quantified by measuring the deviation at approximately 25 upgaze and approximately 35 downgaze. The amount of anterior transposition was determined by both the severity of the inferior oblique overaction and the extent of the V pattern. A satisfactory result was defined as V-pattern incomitance\10. There is evidence that measuring the horizontal deviations in extreme upand downgaze can increase the magnitude of the deviation patterns. Decisions and results based on approximate head positions in alphabet-pattern strabismus may be a bias in this study. Another point to take into account is the strength of the superior oblique muscle. It should be described before and after the surgery for each case. It is plausible that patients with a normal superior oblique might have a different outcome than patients with superior oblique underaction. We suggest the need for a prospective study, controlling the head position for strabismus measurements and the strength of the superior oblique muscles before and after surgery.We also believe it is important to compare surgical results with decisions based on extreme head position measurements to the ones based on the classical measurements at 25 .

Comparação do teste modificado de fixação preferencial com o convencional em pacientes com estrabismo

PURPOSE: To compare the accuracy of the fixation preference test performed with the patient touching and looking at the fixation target, to the conventional method test done with the patient only looking at it. METHODS: A pilot transversal and prospective study was done with 40 strabismic patients with deviations greater than 10 prism diopters, from 7 to 30 years old. RESULTS: The modified test had a sensitivity of 93% (IC 95%=68.53 - 98.73%) and specificity of 77% (IC 95%=57.95 - 88.97%); while the conventional test had a sensitivity of 93% (IC 95%=68.53 - 98.73%) and a specificity of 46% (IC 95%=28.76 - 64.54%). CONCLUSIONS: Our results suggest that the modification of the fixation preference test by asking the patient to touch the fixation target might reduce the number of false positive results of the test.