Objective To investigate the distribution of refractive errors and their association with ocular biometric data, family history and environment variables in medical university students of first to six semesters of UNIVAG - MT. Methods A general ophthalmological exam was performed including, corneal topography, and ocular optical biometry. Lens power has calculated by Bennett and Rozema’s formula. A questionnaire regarding family history of myopia and lifestyle visual activities was applied. Only university students with normal ophthalmological exams were included. Statistical significance was considered at the level of p<0.05. Results One hundred twenty-eight students were selected, whereas other 13 were excluded. The mean age was 21.28 ± 2.18 years. Forty-four (34.4%) participants were males. Regarding refractive errors, 18 (14.1%) were hyperopic, 41 (32%) were emmetropic, 61 (47.7%) were myopic, and 8 (6.3%) were high myopic. The mean and standard deviations of spherical equivalents, axial lengths, keratometries (K1 and K2), and lens powers were -1.27 ± 2.21 D, 24.17 ± 1.07 mm, 42.90 ± 1.25 D, 43.94 ± 1.37 D, and 22.62 ± 1.73 D, respectively. In relation to the family history of myopia, one parent was myopic in 28 (50%) of subjects, and both parents were myopic in 7 (12.5%) subjects. The average of hours per week spent outdoors were 5.82 +/- 7.38 hs. and spent 6.85 +/- 6.26 hs. at sports activities at night. Conclusion Myopia was the most frequent refractive error among the medical university students subject of this study, and was approximately three times higher than those reported for other samples of Brazilian population. There was a positive correlation between refraction errors and axial length.

Propôs-se desenvolver uma fórmula baseada na ceratometria corneana e diâmetro anteroposterior do globo ocular para estimar a refração esférica objetiva, ou poder esférico estimado. Métodos: Estudo retrospectivo, transversal e observacional, selecionou prontuários de 150 pacientes míopes, consecutivos, atendidos no Oftalmocenter Santa Rosa -Cuiabá -MT, entre o período de 2017 a 2019. Coletou-se dados da idade, sexo, acuidade visual, refração com cicloplegia, e resultados da ceratometria e diâmetro anteroposterior. Utilizou-se a regressão linear múltipla para determinar os possíveis modelos. Resultados: Dos 150 prontuários, 100 olhos direitos continham todos os critérios de inclusão. A idade média foi de 17 ± 6,2 anos, sendo 49 do sexo masculino. A média e o DP da miopia, astigmatismo, K 1 , K 2 e diâmetro anteroposterior foram de -4