Postnatal Developmental Changes of Vitreous and Lens Volumes in Sprague-Dawley Rats

Abstract

Purpose: To study the postnatal changes in the vitreous and lens volumes in Sprague-Dawley rats. Methods: Six eyes from Sprague-Dawley rats at each age (postnatal days 1, 6, 12, 21, 30 and 120) were obtained and cryosectioned without fixation. The areas of vitreous, lens and intraocular cavity in the sections were measured separately and their volumes calculated. The percentages of vitreous and lens volumes in the intraocular cavity of each eye were also calculated. Results: The rat vitreous volumes (means ± SE) were 5.2 ± 0.5 µl on day 1, 13.4 ± 0.6 µl on day 6, 22.2 ± 1.0 µl on day 12, 27.8 ± 0.6 µl on day 21, 33.3 ± 1.3 µl on day 30 and 52.4 ± 1.9 µl on day 120. The lens volumes were 3.5 ± 0.2 µl, 7.7 ± 0.4 µl, 10.6 ± 0.4 µl, 15.1 ± 0.5 µl, 19.6 ± 0.8 µl and 43.0 ± 1.3 µl, respectively, in each time group. The vitreous and lens measurements revealed different growth rates and trends. Conclusion: Our systematic data quantify the postnatal development of the lens and the vitreous, and also provide a reference for the ocular volumes of rats at specific postnatal ages.

Retinal ganglion cell neuroprotection induced by activation of alpha7 nicotinic acetylcholine receptors

“…In previous studies using intravitreal injections of PNU-282987, 5 µl of 100 µM PNU-282987 provided complete neuroprotection against loss of RGCs (Iwamoto et al, 2014). When injected into the vitreal chamber, 100 µM PNU-282987 would dissolve in 50 µl of vitreous humor (Sha and Kwong, 2006), to make a final concentration of 10 µM. Although only a small amount of PNU-282987 would reach the retina with one eye drop application, it is likely that repeated application of 500 µM and 2 mM PNU-282987 eye drops result in a final concentration near 10 µM PNU-282987 in the retina after 1 month to provide neuroprotection.…”

Local signaling from a retinal prosthetic in a rodent retinitis pigmentosa modelin vivo

“…The synaptic blocker cocktail consisted of two glutamate receptor antagonists (DAP-5 (50 μM) and CNQX (10 μM), Sigma-Aldrich) and three inhibitory receptor antagonists (picrotoxin 10 μM, TPMPA 50 μM, strychnine 10 μM; Sigma-Aldrich) dissolved in lactated Ringer’s solution. These concentrations represent the final concentrations in the vitreous and were calculated using the estimated vitreal volume for the rat eye (52.5 μl; Sha and Kwong 2006). A complete block of synaptic signaling was characterized by a complete or nearly complete decline in spontaneous activity within 5 minutes of synaptic blocker injection.…”

Investigation of nanoparticles using magnetic resonance imaging after intravitreal injection

“…These magnetic nanoparticles were chosen based on non‐toxicity found in our previous study 14 . The chosen injected volume (3 µL into a 52‐µL rat vitreous) 15 of particles is similar to what could be used in a human eye (50–300 µL into a 4‐mL human vitreous) as is done clinically. Animals were kept for 1 h, 1 day or 5 weeks before MRI scanning.…”