Pupil size in refractive surgery candidates.

Area of Science:

• Ophthalmology
• Optometry
• Biomedical Optics

Background:

• Accurate pupil size measurement is crucial for refractive surgery planning and understanding ocular physiology.
• Variations in pupil size due to lighting conditions (scotopic, mesopic, photopic) can impact visual outcomes.
• Existing methods for pupil measurement may have limitations in accuracy or controlled conditions.

Purpose of the Study:

• To compare pupil size measurements using the Procyon pupillometer under scotopic and mesopic conditions.
• To assess pupil size measurements using the Humphrey videokeratographer under photopic conditions.
• To analyze the influence of age, gender, and refractive error on pupil size.

Main Methods:

• Pupil sizes of 96 refractive surgery candidates (192 eyes) were measured using the Procyon pupillometer PS2000 SA and Humphrey Atlas 992 corneal topographer.
• Pupil sizes were recorded under scotopic (0.04 lux), mesopic-low (0.4 lux), and mesopic-high (4 lux) illumination.
• Anisocoria and pupillary unrest were analyzed across different age groups, genders, and refractive error levels.

Main Results:

• Median pupil diameters were 6.54 mm (scotopic), 5.62 mm (mesopic-low), and 4.09 mm (mesopic-high) with the Procyon pupillometer.
• The Humphrey topographer measured a median pupil size of 3.65 mm.
• Pupil size significantly decreased with age after the fifth decade (P<.05), with no significant relationship found with gender or refractive error. Pupillary unrest was highest under mesopic-high conditions.

Conclusions:

• Both the Procyon pupillometer and Humphrey videokeratographer demonstrate an inverse correlation between pupil size and age.
• The Procyon pupillometer offers an objective and reliable method for measuring pupil size under controlled lighting.
• Age is a significant determinant of pupil size, while gender and refractive error show no significant correlation.