Ophthalmology in China ›› 2013, Vol. 22 ›› Issue (2): 117-120.

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Comparison between light house visual acuity chart and Freiburg electronic visual acuity chart

 YANG  Yao-Hua1,   Zhen-Yi2, WU  Hai-Tao1,   Li-Peng3-　   

  1. 1. The Aviation Medical Assessment and Training Center in Hangzhou, Hangzhou 300007, China; 2. National Engineering Research Center for Ophthalmic Equipments, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China;  3. Shenzhen MOPTIM Imaging Technique Co., Ltd
  • Received:2012-11-23 Online:2013-03-25 Published:2013-03-26
  • Contact: ZHEN Yi, Email：dr_zhenyi@yahoo.com.cn

Cited

6

Abstract: Objective To investigate the clinical application value of Freiburg electronic visual acuity chart by comparing the consistency and repeatability between light house visual acuity chart (LHVAC) and Freiburg electronic visual acuity chart(Freiburg). Design Evaluation of diagnostic technology. Participants Eighty-six staff members（45 men and 41 women）from the Air Force of Hangzhou Aviation Medicine Training Center were involved, with an average age of 26.3±2.1 years. Method All subjects were examined randomly and successively using LHVAC and Freiburg. All examinations were done in the same room. The brightness of the room was less than 3 lux and the work distance was 3 m. For each subject, the difference in visual acuity measurements obtained with the two visual acuity charts were evaluated by paired t-test and R value of the correlation coefficient were calculated. Main Outcome Measures LogMAR visual acuity obtained using the two charts. Results When used first, the logMAR visual acuity of LHVAC was 0.19±0.23. Accordingly, the result of Freiburg was 0.20±0.15. The difference between the two results was -0.011±0.141, the results showed that these two charts had no statistically significant difference between them（t=-0.741, P=0.461）and had significant correlation (r=0.808, P=0.000). When used in second, the logMAR visual acuity of LHVAC chart was 0.32±0.25. Accordingly, the result of Freiburg  was 0.20±0.15. The difference between the two results was -0.118±0.151, the results showed that these two charts had a statistically significant difference between them（t=7.191, P=0.000, however the results were significantly correlated (r=0.810, P=0.000). Using LHVAC, the difference between the two examinations was significant (F=11.872，P=0.001) and the correlation coefficient was 0.938 (P=0.000). Using Freiburg examination, the difference between the two examinations was not significant (F=0.019，P=0.890) and the correlation coefficient was 0.986 (P=0.000). Conclusion The influence of examination order on Freiburg was less than with LHVAC and the repeatability of Freiburg was better than LHVAC. (Ophthalmol CHN, 2013, 22: 117-120)

Key words: visual acuity chart, light house visual acuity chart, electronic visual acuity chart