Objective To investigate changes in refraction and vitreous length during formdeprivation and visual re-exposure in guinea pig eyes.Methods It wag an experimental study.Ninety-six guinea pigs with age of three weeks were randomly divided into form-deprivation and normal control groups (n=48 in each group).The form-deprivation group was further divided into 4 subgroups(n=12 in each subgroup)which underwent monocular form-deprivation for 1,2,4,and 6 weeks,respectively.At the end of each time point,the form-deprived eyes in all animals were visually re-exposed and followed for 3 (n=6)and 7 days(n=6).The control group was also divided into four subgroups (n=12 in each subgroup)to match the time-points of the form-deprivation group.During form-deprivation and recovery,vitreous length and refraction in each group was measured and compared.Results There was significant difference in vitreous length (F=6.108,28.222,19.195) and refraction(F=12.504,15.003,6.829)when compared deprived eyes with contralateral eyes 2,4,or 6 weeks after form-deprivation(P<0.05).Difierence in refraction between deprived eyes and contralateral eyes was-2.36 D,-3.64 D and-3.68 D at 2,4,6week, respectively. Difference in vitreous length was 0.08 mm, 0.19 mm and 0.22 mm. During visual re-exposure, form-deprived eyes changed into hyperepia as compared with contralateral eyes. At day 3 point,there was no significant difference in refraction and vitreous length between form deprived eyes and contralateral eyes in 1 week and 2 weeks groups ( F = 0. 032,0. 280 ; P > 0. 05 ). After 7 days recovery,vitreous length and refraction in deprived eyes almost backed to level of contralateral eyes in 1 and 2 weeks groups. At day 3 point, there was significant difference of refraction and vitreous length between form-deprived eyes and contralateral eyes in 4 weeks group and 6 weeks group. After 7 days recovery, there was significant difference in vitreous length for 4 weeks group and there was significant difference in both refraction and vitreous length for 6 weeks group (F = 4. 108, 6.317; P < 0.05 ). Conclusion Form-deprivation causes myopic chanes in deprived eyes, during visual re-exposure the refraction recovers and the extent depends on the length of form-deprivation. The recovery rate is faster during the first 3 days and then slower after 3 days. The mechanism of form-deprivation myopia in guinea pig eyes is similar to that of myopia in juvenile human beings.%目的 研究青少年豚鼠不同形觉剥夺时期,眼球屈光不正度数和玻璃体腔长度恢复的情况.方法 实验研究.将96只3周龄豚鼠随机分为两组,即剥夺组和正常组各48只.剥夺组再随机分为4个组,每组12只,分别予头套法形觉剥夺1、2、4、6周,单眼剥夺后每组6只予去头套恢复3 d.另6只恢复7 d;正常组亦分为4个组,分别与剥夺组形成对照.在剥夺前后及恢复期后测量豚鼠屈光不正度数和玻璃体腔长度的变化,并比较实验眼、自身对照眼和正常对照眼之间的差异.采用单因素方差分析来比较实验眼、自身对照眼及正常对照眼的眼轴长度、屈光不正度数及玻璃体腔长度之间的差异,进一步两两比较采用LSD检验分析.结果 实验眼形觉剥夺2、4、6周时屈光不正度数(F=12.504,15.003,6.829)及玻璃体腔长度(F=6.108,28.222,19.195)与自身对照眼的差异有统计学意义(P<0.05),两眼屈光不正度数之间的差值分别为-2.36、-3.64、-3.68 D,两眼玻璃体腔长度的差值分别为0.08、0.19、0.22 mm.在去除头套后,实验眼(形觉剥夺恢复后)较对照眼向远视方向发展.剥夺2周的实验眼在恢复3 d时,两组实验眼和对照眼屈光不正度数和玻璃体腔长度之间已无统计学意义(F=0.032,0.280;P>0.05),恢复7 d时,实验眼屈光不正度数及玻璃体腔长度可恢复到对照眼水平.剥夺4周和6周的实验眼在恢复3 d时,两组实验眼和对照眼屈光不正度数和玻璃体腔长度之间差异有统计学意义(F=7.658,8.415,5.150,6.061;P<0.01);而剥夺4周的实验眼在恢复7 d时两眼屈光不正度数无统计学意义,玻璃体腔长度差异有统计学意义(F=4.020,P<0.05),剥夺6周的实验眼在恢复7 d时两眼屈光不正度数和玻璃体腔长度差异仍有统计学意义(F=4.108,6.317;P<0.05).结论 豚鼠形觉剥夺可使实验眼形成明显的近视,实验眼在去除剥夺3 d内恢复速度较快,3至7 d时速度减慢.近视的恢复以及恢复程度取决于剥夺时间的长短,剥夺时间越长,近视越难恢复.
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