Title : Impact of caffeine intake on ocular physiology
Abstract:
Caffeine is a substance that people use in a variety of forms and in varying amounts in their daily life all around the world. Accommodation is the ability of Eye’s to adjust its focus on objects at varying distances, plays a vital role in visual acuity and overall eye function. This process involves the contraction or relaxation of the ciliary muscles, altering the shape of the eye's crystalline lens as it adapts to objects at various distances. Pupillary response and accommodation are important physiological processes of the eye that affect vision. Pupil dilation is regulated by the autonomic nervous system, its a dynamic response to changes in ambient light, influencing the amount of light entering the eye and subsequently affecting visual perception. The regulation of IOP is primarily governed by the equilibrium between the production and drainage of aqueous humor.
MATERIAL AND METHODS: This cross-sectional study aimed to investigate the health-related characteristics of 88 healthy young individuals (44 with Coffee consumption and 44 without consumption of Coffee) from SDUAHER, Kolar. Ethical considerations include obtaining informed consent, and the study has received approval from an ethics committee.
INCLUSION CRITERIA: Healthy participants of both Gender specifically aged 19 to 30 years, Refractive correction of spherical equivalent ≤ ±0.50D, and achieving a best spectacle-corrected visual acuity of 6/6 or better IOP less than 21mmHg
EXCLUSION CRITERIA: History of ocular surgery, Systemic/Ocular diseases, Accommodative anomalies and Pupillary defects, Regular smokers
Subjects are experimentally grouped as Group A are participants with Coffee intake & group B without coffee intake.
- For participants in Group A, 50ml of coffee (1.2g of caffeine in 50ml milk) and Group B are participants without coffee. A thorough ocular examination was be conducted, including patient history, visual acuity testing, slit lamp examination, and fundus examination.
- Following a standardized 20-minute interval and 40-minute post-coffee consumption,
- Monocular amplitude of accommodation utilized the Royal Air Force (RAF) Ruler, with subjects wearing spectacles at a 15 mm vertex distance and focusing on a movable target at 40 cm.
- Pupil size, measured in a dimly lit room using a ruler, involved recording the horizontal diameter in cm, which was then converted to millimeters.
- iii. Intraocular pressure (IOP) was assessed with a Non Contact Tonometer.
RESULTS: In Group A out of 44, Both Male and Female participants are equally distributed as 22 with a mean age of 23.70 ± 1.19. Whereas, in Group B out of 44, 23 were Female and 21 were male participants with a mean age of 23.52 ± 1.12.
Our study revealed a significant increase in both the amplitude of accommodation and pupil diameter following consumption of a caffeine-containing beverage.
CONCLUSION: Our findings suggest that caffeine may temporarily enhance accommodation and pupil size without substantially impacting IOP.
