Multifocal Electroretinography in Assessment of Macular Function after Internal Limiting Membrane Peeling in Macular Hole Surgery.

PURPOSE: Internal limiting membrane (ILM) peeling is important for macular hole (MH) surgery but may have secondary effects visible on spectral domain optical coherence tomography (OCT) and multifocal electroretinography (mfERG). We relate integrity of inner and outer macular layers with functional results with mfERG. METHODS: Nonrandomized prospective study of 33 consecutive eyes of 33 patients with macular hole who underwent vitrectomy with ILM peeling. Best-corrected visual acuity was assessed, and integrity of external layers was measured using OCT. Each component of mfERG, N1 and P1 amplitude and latency, was also measured. RESULTS: All eyes showed macular hole closure. Visual acuity improved from 20/400 to 20/40 in the Snellen visual acuity chart (P < 0.001), and OCT external lines were intact in 19 eyes and disrupted in 14 eyes. Postoperatively, N1 and P1 amplitudes in ring 1 increased compared to preoperative values (P < 0.001 for both). Latency remained delayed for both N1 and P1 wave. In the group of 19 eyes with integrity of outer retinal layers, N1 amplitude in ring 1 was superior to the group of 14 patients with disrupted outer retinal layers (P=0.042). CONCLUSIONS: In macular hole surgery, structure analysis in OCT is one of the important outcomes for the retinal surgeon. Functional results are parallel with anatomic results, but visual gain is limited. The limited recovery in mfERG suggests an alteration of retinal physiology that could explain limited vision recover.

Correção de medida ultrassonográfica de carcaça em coelhos usando modelo linear misto com covariáveis / Correction ultrasonographic measurement of carcass in rabbits using mixed linear Model with covariates

Objetivou-se avaliar a correção da medida ultrassonográfica da área do músculo Longissimus dorsi, em coelhos da raça Nova Zelândia, pela análise de covariância usando modelos mistos. Foram realizadas análises em delineamento em blocos completos ao acaso, com cinco tratamentos (operadores) e seis blocos (animais), considerando na análise: a inexistência de covariáveis; a covariável comprimento de olho de lombo; a covariável profundidade de olho de lombo; e as duas covariáveis juntas. Como os animais são uma amostra aleatória, o efeito de bloco foi considerado como aleatório. Consideraram-se as covariáveis como medidas com efeito fixo sem erro, independentemente do tratamento e do comportamento linear. As estatísticas de critério de decisão CV%, R ² e R ¯ ² evidenciaram relação direta entre si e podem ser consideradas para avaliar a precisão experimental em ensaios com avaliação de carcaças. Os valores das estatísticas AIC, BIC e AICC apresentam coerência com a interpretação dos critérios de decisão e indicam que o modelo com duas covariáveis proporciona resultados acurados. A inclusão das covariáveis complementa o controle de local com melhoria na precisão do experimento. A utilização das medidas ultrassonográficas de profundidade e comprimento corrige a média da área do músculo Longissimus dorsi avaliado por diferentes operadores.(AU)

The objective of this study was to evaluate the correction ultrasonographic measurement of area the Longissimus dorsi muscle in New Zealand rabbits by covariance analysis using mixed linear models. The analyzes were performed in randomized block design with 5 treatments (operators) and 6 blocks (animals), considering in the analysis: absence of covariates; rib eye length as covariate; rib eye depth as covariate; the two covariates together. As the animals are a random sample, the block effect was considered to be random. The covariates were considered as measures of fixed effect without error, independent of treatment and linear comportment. The decision criterion statistics CV%, R², and R ¯ ²showed a direct relationship between them and can be taken into consideration to evaluate the experimental accuracy in tests with carcass evaluation. The AIC, BIC, and AICC statistics are consistent with the interpretation of the decision criteria and indicate that the two covariates in model provides accurate results. The inclusion of covariates complements the local control to improve the accuracy of the experiment. The use of ultrasound measurements of depth and length corrects the mean area of the Longissimus dorsi muscle evaluated by different operators.(AU)