[Effect of time limited form deprivation on the development of myopia in guinea pigs].
OBJECTIVE
To investigate the effect of time limited form deprivation on the development of form-deprived-myopia (FDM) in guinea pigs.


METHODS
Four-week-old guinea pigs (n = 20) were randomly divided into four groups. Group I was used as normal control without any treatment. In group II-IV, unilateral form deprivation was produced with eye patch for 4 weeks. In group II, eye occlusion was fitted continuously. In group III and IV, occlusion was removed each day for 1 or 4 hours. Refractive development was monitored by retinoscopy and A-scan ultrasonography before and after experiment.


RESULTS
After 4 weeks, varied degree of axial myopia was developed in the groups II and III with eye occlusion. Continuous form deprivation produced -5.49 D of relative myopia and the fellow eyes produced +0.76 D of relative hyperopia. One hour of unrestricted vision was sufficient to reduce the degree of FDM by about 50%. The eyes allowed 4 hours of unrestricted vision did not result in myopia.


CONCLUSIONS
Long periods of form deprivation can be counterbalanced by quite short periods of unrestricted vision.
Department of Ophthalmology, Qilu Hospital of Shandong University, Ji'nan 250012, China. zycheng@tom.com
Zhen-Ying
ZY
Cheng
Jing-Hai
JH
Li
Rong
R
Li
Jian-Qiao
JQ
Li
D000818:Animals; D005123:Eye / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006168:Guinea Pigs; D008297:Male; D009216:Myopia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D011897:Random Allocation; D042262:Retinoscopy; D012683:Sensory Deprivation / Q000502:physiology*; D013997:Time Factors; D014463:Ultrasonography; D014785:Vision, Ocular / Q000502:physiology