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Chromatic pupillometry is an emerging modality in the assessment of retinal and optic nerve disorders. Herein, we evaluate the effect of low and moderate refractive errors on pupillary responses to blue- and red-light stimuli in a healthy older population. This study included 139 participants (≥50 years) grouped by refractive error: moderate myopes (>−6.0D and ≤−3.0D, n = 24), low myopes (>−3.0D and 0.5D and R = −0.26, P R = 0.37, P R = 0.43, P P = 0.45), while constriction amplitudes to red light were greater in hyperopes compared to emmetropes (P = 0.04) at moderate to bright light intensities (12.25–14.0 Log photons/cm²/s). Our results demonstrate that low and moderate myopia do not alter pupillary responses to ramping-up blue- and red-light stimuli in healthy older individuals. Conversely, pupillary responses to red light should be interpreted cautiously in hyperopic eyes.

A method for rapid and objective assessment of ocular lens density and transmittance is needed for research and clinical practice. The aim of this study was to determine whether the Purkinje image-based technique can be used for objective and accurate quantification of spectral density and transmittance of ocular media (the mainly crystalline lens) in visible light. Twenty-six individuals (10 young, 9 middle-aged and 7 older individuals) participated in this study. Spectral lens density was evaluated by detecting the intensity of the IVth Purkinje image for different wavelengths. Subsequently, optical density index (ODI), the area under the curve in the lens density spectrum, was calculated and ODIs were compared with clinical lens opacification scales assessed subjectively using a slit lamp. Spectral lens transmittance was estimated from the lens density spectrum. Lens densities were higher in the short wavelength region of the visible spectrum across all age groups. ODI was highly correlated with the clinical opacification scale, while lens transmittance decreased with aging. Our results showed that spectral transmittance of the human crystalline lens can be easily estimated from optical density spectra evaluated objectively and rapidly using the Purkinje image-based technique. Our results provide clinicians and scientists with an accurate, rapid and objective technique for quantification of lens transmittance.

Chromatic pupillometry is an emerging method for evaluating ocular health that relies upon the differential stimulation of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). Although it has been investigated in conditions affecting the outer or inner retina, there is a paucity of studies in conditions where the anterior chamber of the eye is affected. Primary angle closure suspects (PACS) are defined as eyes with narrow anterior chamber angles and intact retina. PACS patients are at risk of developing primary angle closure glaucoma and are prophylactically treated by performing laser peripheral iridotomy (LPI). Here we evaluated pupillary responses to monchromatic lights in 18 PACS before and after LPI, and compared the results with those of 36 age-matched controls who had gonioscopically open angles. Dose response curves for pupillary constriction were similar between PACS patients and controls (p = 0.98 for blue and 0.90 for red light) and within subjects pre- and post-LPI (p = 0.58 for blue and 0.20 for red light). Baseline-adjusted pupillary constriction responses to blue and red lights were similar in controls and PACS, and not altered after LPI. Our findings suggest that narrow irido-corneal angles and LPI do not influence pupillary responses in PACS.