Abstract
Purpose :
To investigate conditions that cause temporal lens opacity, we tested chemical and physical factors, such as anaesthesia dose, ocular surface dryness, and infrared (IR) light exposure in anaesthetised C57BL/6N mice.
Methods :
Mice were anaesthetised with a low (80%; tiletamine/zolazepam 32 mg/kg and xylazine 8 mg/kg, intraperitoneal injection) or high (120%; 48 mg/kg and 12 mg/kg) dose of anaesthetic and examined every 5 min from 10 to 30 min after anaesthesia was induced. Lens opacity levels were assessed and graded (grade 1; clear lens to grade 6; very severe opacity) using the standard classification system. Eight groups of mice (at least three mice per group) were used to investigate the effect of three factors on the formation of lens opacity, including anaesthetic dose, ocular surface dryness, and IR light exposure. Finally, we explored the reversibility of lens opacity.
Results :
Regardless of the anaesthetic dose, lens opacity grade was 1-2 in moisturised eyes with application of 0.5% carboxymethylcellulose, and 5-6 in dry ocular surface conditions. Lens opacity in mice with high-dose anaesthetic in the dry ocular surface condition was not different from that of mice with low-dose anaesthetic. Lens opacity grade 1-2 was noted in eyes in the wet ocular surface condition, regardless of IR light exposure. During IR light exposure in eyes in the dry ocular surface condition, lens opacity (grade 6) in mice with high-dose anaesthetic was not different from that (grade 6) in mice with low-dose anaesthetic. One hundred percent (5/5) of eyes with lens opacity of grade 5-6 induced by ocular surface dryness began to regain transparency at 1 h; all lens opacity was completely reversed to grade 1 by 6 h.
Conclusions :
We demonstrated that ocular surface dryness might be a relevant factor for the formation and progression of lens opacity in anesthetized C57BL/6N mice. Anaesthesia dose and IR light exposure did not strongly influence lens opacity formation. Furthermore, eyes with corneal dryness-induced lens opacity recovered to normal status without additional intervention.
This is a 2020 ARVO Annual Meeting abstract.