Incidence And Risk Factors Of Near Vision Impairment (NVI) In Patients With Asthenopia

Objective: The purpose of this project is to investigate the occurrence of NVI in patients with visual fatigue.To explore the possible influencing factors that cause NVI.to explore methods that can help improve near vision.Methods: From May 2017 to May 2018,51 patients with 102 eyesight who were diagnosed as visual fatigue at the outpatient clinic of Anhui Provincial Hospital Affiliated to Anhui Medical University were selected.According to whether or not near vision is impaired in daily life,it is divided into daily-NVI group(24 cases and 48 eyes)and non-NVI group(27 cases and 54 eyes).Record the detailed information of gender,age,visual fatigue course,working condition,wearing glasses in daily life,daily use time of electronic devices such as mobile phones,computers,TV,outdoor sports time,sleep time,etc.Then perform routine eye examinations such as the anterior segment,fundus,intraocular pressure,and tear film rupture time.Standard subjective optometry and binocular eye movement parameters such as accommodative amplitude,accommodative sensitivity,negative/positive relative adjustment(NRA/PRA),near and far horizontal divergence and divergence amplitude.Finally,the survey of "Myopia Function Evaluation Scale Survey" was conducted.Results: In this study,27 patients(53%)with NVI in naked eye and 24 patients(47%)with impaired near vision in daily life,and all patients had a significant improvement in visual acuity after correct optometry,and there was no one who has best corrected near visual acuity impairment.The average age of patients with daily near vision impairment(52.67 ± 7.46)was significantly higher than that of patients without near vision impairment(40.26 ± 12.19).The proportion of patients aged ?45 years in the daily-NVI group was significantly higher than that in the non NVI group(P <0.01).There were significant differences between the two groups in subjective optometry,accommodative amplitude,accommodative sensitivity,near and far horizontal divergence(BI(6m,40cm),BO(40cm))and near and far horizontal divergence amplitude.Conclusion: Most patients with visual fatigue are associated with NVI,and most of them are over 45 years old.As the age increases,the eyeballs have a tendency of hyperopia,which is a possible cause of multiple near vision impairment in the elderly.Correcting the hyperopia condition with accurate optometry can effectively improve near vision.The decrease in accommodation caused by aging is not enough to cause changes in NVI,and the imbalance between accommodation demand and accommodation may be the main influencing factor leading to the decrease in near vision.People with near vision impairment need a stronger vergence when looking at near objects.Frequent mobilization of eyeballs can enhance the capabilities of vergence,so patients with NVI can properly do some training of assembly functions,to supplement the imbalance in the ability of accommodation.