Clinical and morphological investigation of Vitreocontrast suspension effect on tissues of the rabbit eye

Purpose. The purpose of this study: clinical and morphological substantiation of the safety of Vitreocontrast suspension during its anterior chamber and intravitreal injection.

Material and methods. The research was performed in 16 (32 eyes) rabbits chinchilla weiting 2-2.5 kg. An amount of 0.1 ml Vitreocontrast was injected into anterior chamber and intravitreally in the right eye, whereas in the left eye the balanced salt solution was applied for control in rabbit’s eyes.

Clinical examination, electroretinography and histology with light microscopy were perfomed after 1, 7, 14, 30 days.

Results. After Vitreocontrast injection into anterior chamber the suspension was precipitated as a 2 mm level. The anterior segment structures of the eye was intact. At clinical examination all eyes were negative for cataract, hemorrhage, retinal detachment and intraocular opacities. After intravitreal injection, the Vitreokontrast appeared as a white mass floating in the vitreous chanal near retina. Suspension mass became smaller during followup, and disappeared completely after 2 weeks in anterior chamber and after 4 weeks in vitreous cavity. There was no any structural tissues changes (conjunctiva, sclera, choroid, retina).

None of the rabbits included in the study developed significant complications following intravitreal injection.

The Vitreokontrast caused no major changes in ERG during the follow-up period in both group. On the 1st day there was a mild reduction of the ERG b-wave amplitude as a reaction on the operation trauma.


Conclusions Light microscopy examination showed no structural changes in the cornea, sclera, iris, choroids and retina.

There was no thinning or visible changes of retinal layers, no changes in cell number and no signs of severe retinal necrosis or cystic degeneration.

The injection of Vitreocontrast suspension into anterior chamber and vitreous cavity is non toxic to the retina and others structures of rabbit eyes.

Key words: chromovitrectomy, intravitreal injection, electroretinography, rabbit eye.