Abstract
Purpose: :
To investigate preferences of blue-light blocking filters in patients with ocular diseases for preventing photophobia or improving subjective contrast.
Methods: :
One hundred and twenty patients who were aware of photophobia and 15 healthy volunteers after pupil dilation were investigated. The enrolled patients were with senile cataract, corneal opacity, retinitis pigmentosa (RP), age-related macular degeneration (AMD), diabetic retinopathy, glaucoma, intracranial disorders and lid spasms (n=15 in each group). Exclusion criteria included eyes with yellow inter-ocular lens implanted, degenerative myopia, moderate and advanced cataract except in the group of senile cataract. Filters of 20 different colors (TOKAI) were tested. Patients were asked to answer the following queries; 1) the filter which completely suppresses the photophobia, 2) the best filter to increase the subjective contrast outside under the sun. As for the questionnaire 1, we selected the filter with the smallest luminous transmittance (LT) and compared its LT values among diseases. The statistical analysis was done on the basis of the LT and the transmission of short wave length (400-500nm) (T-short).
Results: :
No statistical difference in LT was detected among diseases for suppressing the photophobia. The healthy volunteer group preferred a filter with significantly lower LT (27%) than the group of cataract, AMD, glaucoma or lid spasms (P<.05) for increasing subjective contrast. Filters with 50% or less T-short were preferred in most patients except for patients with cataract, AMD and glaucoma for suppressing photophobia or increasing subjective contrast.
Conclusions: :
Filters with lower LT is preferred by subjects with increased amount of incident light to prevent photophobia. Filters with 50% or less T-short suppress photophobia and increase subjective contrast in most patients with ocular diseases.
Keywords: quality of life • brightness and lightness • low vision