Impact of topical anaesthetic eye drops on corneal thickness and intraocular pressure measurements in broiler chickens: implications for ophthalmological evaluation

1. Ophthalmological examinations in poultry are essential for monitoring overall health and welfare. These are commonly assessed using intraocular pressure (IOP) and corneal thickness (CT). This study examined the effects of 0.5% proparacaine HCl topical anaesthetics on IOP and CT across various corneal regions in broiler chickens.2. Ninety male broilers were housed under controlled conditions and underwent ophthalmic examinations, including CT and IOP. Baseline measurements were recorded for both eyes, after which 0.5% proparacaine HCl drops were instilled in the right eyes, while the left eyes received physiological saline solution (PSS) drops as controls.3. Significant differences were observed between proparacaine HCI and PSS groups in nasal, temporal, inferior, superior and central CT measurements post-treatment, with proparacaine HCI leading to decreased CT values across various corneal areas compared to PSS. Correlations between IOP and CT measurements varied, which suggested potential disruptions in ocular dynamics following topical intervention.4. The findings emphasised the necessity of accounting for the influence of topical anaesthetics on ocular assessments to ensure accurate diagnosis and treatment.