Abstract
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.
Highlights
A method for rapid and objective assessment of ocular lens density and transmittance is needed for research and clinical practice
After confirming the accuracy of the Purkinje image-based technique, we investigated whether a lens transmittance spectrum can be estimated from the lens density spectrum using the ocular media model proposed by van de Kraats and van N orren[26]
In the results for optical density index (ODI), which is the area under the curve of the optical density spectrum in the range from 460 to 600 nm, one-way analysis of variance (ANOVA) showed a significant main effect of age (F (2, 23) = 22.55, P < 0.001, η2 = 0.66)
Summary
A method for rapid and objective assessment of ocular lens density and transmittance is needed for research and clinical practice. Aging is associated with an increase in spectral optical density and a concomitant decrease in transmittance of the human crystalline lens, especially in the short wavelength blue visible region of the light spectrum[1,2,3]. Najjar et al verified that lens density measured using sHFP correlates with clinical evaluation and yields a better predictor of increase in lens density with aging than other physical and psychophysical m ethods[27]. Psychophysical methods such as sHFP are difficult to implement for individuals with visual impairments or children as these procedures are lengthy and rely on the subject’s feedback, visual perception and fixation aptitudes. These techniques were time-consuming and inconvenient because the pupil needs to be dilated with pharmacological agents
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
