Abstract: Objective To study the fundus diseases that primary and middle school students may be susceptible to suffer, and to understand the prevalence rate and constituent ratio of these diseases. Methods A total of 9 504 students were examined from November 2015 to February 2017 to find out their ocular fundus conditions. They were from all the primary and secondary schools directly subordinate to Dagang Oilfield headquarters. Among the 9 504 participants 4 998 were male and 4 506 were female, with the age span of 5 to 23 and the average age of (13.40±3.41). Our medical examination included uncorrected visual acuity examination and fundus oculi photography. The distribution of fundus diseases was analyzed, including gender, vision acuity and age composition of patients with major diseases. Results Among the 9 504 students, 4 314 had emmetropic eyes, and 5 190 had refractive errors. A total of 9 126 out of the 9 504 examined students had normal ocular fundus (96.02%), while those with abnormal ocular fundus accounted for 378 (3.98%). The main types of abnormal ocular fundus included the tessellation fundus 354 (3.72%), followed by the large depression of optic disk 16 (0.17%). Among all the 354 cases with tessellation fundus, 179 were male and 175 were female. There were 257 students whose visual acuity ≤0.3 / 0.3, and the prevalence was higher in 17-19 years old students (5.86%). Conclusion It has been revealed in this epidemiological survey that the main abnormal ocular fundus of primary and middle school students in Dagang is tessellation fundus. Most of the tessellation fundus are caused by middle and high myopia, and very few are found in emmetropic students. It has also been found that the incidence of tessellation fundus increases significantly with the increase of age. The large depression of optic disk ranks the second in the abnormal ocular fundus, which is mostly physiological.

Key words: fundus oculi, eye diseases, epidemiologic studies, TIANJIN, Dagang oilfield, primary and secondary school