Corneal viscoelasticity differences between diabetic and nondiabetic glaucomatous patients.

PURPOSE: To investigate corneal viscoelasticity in primary open-angle glaucoma patients with and without diabetes mellitus, and to correlate corneal hysteresis (CH) with central corneal thickness (CCT). METHODS: In this cross-sectional study, 44 primary open-angle glaucoma patients [19 with diabetes (34 eyes) and 25 without diabetes (40 eyes)] underwent a complete ophthalmic examination. Data collected by masked investigators included CH and CCT using the Ocular Response Analyzer. The mean of 3 measurements was considered for each test. We analyzed the difference between the mean CH in both groups using a general linear model. Partial correlation coefficient between CH and CCT was also calculated. RESULTS: Mean+/-SD age in diabetic and nondiabetic groups was 67.1+/-8.7 and 65.9+/-15.1, respectively (P=0.77). There was no significant difference regarding mean CCT between diabetic (531.7+/-31.3 mum) and nondiabetic (546.6+/-37.3 mum) groups (P=0.21). Patients with diabetes presented significantly higher CH values than patients without diabetes (9.1+/-1.9 mm Hg vs. 7.8+/-1.7 mm Hg, P=0.04). There was a significant and positive correlation between CH and CCT for all patients (r=0.407, P<0.001). CONCLUSIONS: Primary open-angle glaucoma patients with diabetes have significantly higher CH values than those without diabetes. CH and CCT results were positively correlated. These findings merit further investigation to assess the role of different CH values on glaucoma evaluation and susceptibility.

Learning effect of standard automated perimetry in healthy individuals.

PURPOSE: To evaluate the learning effect in standard automated perimetry using SITA strategy, central 24-2 program, possible associated factors and spatial distribution in individuals with no perimetry experience. METHODS: A total of 55 healthy subjects were submitted to Humphrey perimetry in two different sessions in one day. Reliability and global indices, and threshold sensitivity at each point were compared between the two examinations. The influence of potential factors (age, gender, and educational level) and the spatial distribution were evaluated regarding alterations between these two examinations. RESULTS: The duration of the test was longer in the first session (median, 5.7 min; interquartile range [IQR], 1.7 min) than in the second (median, 5.3; IQR, 1.1 min) (p=0.002). The median (IQR) of false negative errors was 2% (6%) in the first examination and 0% (6%) in the second (p=0.04). The mean (standard deviation) in the mean deviation (MD) global index was -2.31 (1.86) dB in the first examination and -1.73 (1.69) dB in the second (p=0.07). No association was observed between the change in MD and age (p=0.29), gender (p=0.69) and educational level (p=0.27). The changes in threshold sensitivity were greater at the peripheral points than at the central points (p<0.001). CONCLUSION: The threshold sensitivity increased in the second examination compared to the first. No factors were associated with this change. The changes in threshold sensitivity were more evident at the peripheral points.

Learning effect of standard automated perimetry in healthy individuals / Efeito aprendizado da perimetria automática padrão em indivíduos saudáveis

PURPOSE: To evaluate the learning effect in standard automated perimetry using SITA strategy, central 24-2 program, possible associated factors and spatial distribution in individuals with no perimetry experience. METHODS: A total of 55 healthy subjects were submitted to Humphrey perimetry in two different sessions in one day. Reliability and global indices, and threshold sensitivity at each point were compared between the two examinations. The influence of potential factors (age, gender, and educational level) and the spatial distribution were evaluated regarding alterations between these two examinations. RESULTS: The duration of the test was longer in the first session (median, 5.7 min; interquartile range [IQR], 1.7 min) than in the second (median, 5.3; IQR, 1.1 min) (p=0.002). The median (IQR) of false negative errors was 2 percent (6 percent) in the first examination and 0 percent (6 percent) in the second (p=0.04). The mean (standard deviation) in the mean deviation (MD) global index was -2.31 (1.86) dB in the first examination and -1.73 (1.69) dB in the second (p=0.07). No association was observed between the change in MD and age (p=0.29), gender (p=0.69) and educational level (p=0.27). The changes in threshold sensitivity were greater at the peripheral points than at the central points (p<0.001). CONCLUSION: The threshold sensitivity increased in the second examination compared to the first. No factors were associated with this change. The changes in threshold sensitivity were more evident at the peripheral points.

OBJETIVO: Avaliar o efeito aprendizado da perimetria automatizada padrão com a estratégia SITA, programa central 24-2, possíveis fatores associados e distribuição espacial em indivíduos inexperientes em perimetria. MÉTODOS: Um total de 55 indivíduos saudáveis foi submetido a exame de perimetria com aparelho Humphrey em duas sessões no mesmo dia. Foram comparados os índices de confiabilidade, globais e limiares de sensibilidade de cada ponto entre os exames. Foram analisados potenciais fatores relacionados (idade, sexo e nível educacional), bem como a distribuição espacial em relação à alteração entre os exames. RESULTADOS: A duração do exame foi maior na primeira sessão (mediana, 5,7 min; amplitude interquartil [AIQ], 1,7 min) do que na segunda (mediana, 5,3; AIQ, 1,1 min) (p=0,002). A mediana (AIQ) da taxa de falsos negativos foi 2 por cento (6 por cento) no primeiro exame e 0 por cento (4 por cento) no segundo exame (p=0,04). A média (desvio padrão) do índice global desvio médio (MD) foi -2,31 (1,86) dB no primeiro exame e -1,73 (1,69) dB no segundo exame (p=0,007). Não houve associação entre a mudança do MD em relação à idade (p=0,29), sexo (p=0,69) e nível de escolaridade (p=0,27). Houve maior alteração na sensibilidade dos pontos periféricos em relação aos pontos centrais (p<0,001). CONCLUSÃO: Houve melhora dos limiares de sensibilidade entre o primeiro e segundo exames. Não foram detectados fatores associados a estas mudanças. Nos pontos mais periféricos do exame, tais mudanças foram mais acentuadas.