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The object of this study was to clarify the ocular structural changes of tree shrews during development and the influence of growth on experimental myopia. Eighty-four eyes of 42 tree shrews (43–1604 days old) were included. The body weight was measured. The axial length was measured using A-mode ultrasonography, and the mean value of both eyes was calculated. Monocular form deprivation (FD) was induced in 13 8-week-old tree shrews. The axial length and refractive error were measured before and at 15, 30,45, 60, 90, and 120 days after FD was induced. The body weights increased rapidly from birth until 100 days, the point at which tree shrews reach maturity. The ocular structures changed rapidly during this period, except for the anterior chamber depth. In the animals with FD, myopia increased rapidly by 45 days following FD at approximately 100 days after birth. However, after this time, myopia increased slowly. Almost the same results were found for the vitreous cavity and the axial length. Our study demonstrated that ocular structural growth changes markedly to the point at which tree shrews reach maturity, and FD myopia may be influenced by ocular growth.

The purpose of this study was to evaluate the correlation between corneal and lens autofluorescence and the various degrees of myopia. Forty-five eyes of 45 myopic patients (mean age ± SD, 23.8 ± 2.4 years; range, 18 to 27 years) were included. Subjects wearing contact lenses were excluded. After inducing mydriasis, we mea¬sured corneal and lens autofluorescence levels, refractive error, and axial length. A significant correlation was found between refractive error and length of the vitreous cavity. Neither anterior chamber depth nor lens thickness correlated with refrac¬tive error. Refractive error was significantly correlated with corneal and lens autofluorescence levels (r = 0.415, P 0.0005). Corneal and lens autofluorescence levels increased as the axial length increased in myopic eyes. This increase may be related to the breakdown of the blood-ocular barrier that we previ¬ously reported.

The purpose of this work was to study the influence of gender in tree shrew eyes with growth and experimental myopia. Ocular components were measured using A–mode ultrasonography in 63 eyes of 63 tree shrews (38 females and 25 males, ages 43–1542 days). Twenty 8–week–old tree shrews (11 males and 9 females) were monocularly fitted with a translucent goggle 3 weeks after eye opening. Optical refractions were also measured using a refractometer. Measurements were performed before and 15 days after form deprivation (FD) was induced. In normally developing male and female tree shrews, the same growth pattern of the ocular components was observed. In experimental myopia, compared with the paired normal eyes, FD eyes were myopic, and the vitreous cavity and axial length were longer in both genders. When myopic changes in FD eyes were compared with control eyes, no statistically significant differences were found based on gender. In tree shrews, gender has no effect on developing eyes and experimental myopia in a comparison of FD eyes and paired controls.