Abstract
Purpose:
To introduce a new classification system for vitreous floaters and to study their prevalence and correlation with ocular biometry.
Methods:
This prospective cross-sectional study conducted at the Antwerp University Hospital involves 191 subjects aged between 17.7 and 78.6 years. For each eye the type and grade of floaters were determined by looking into a light box and pointing at a table with the shapes of the most common types of floaters, which is repeated using a modified blue light entoscope (vitreoscope). Subjects were also asked to answer a short survey to determine how their floaters affect their daily lives. Finally subjects underwent measurements of autorefraction, ocular biometry (Zeiss IOL Master), keratometry (Oculus Pentacam), logMAR visual acuity, intraocular pressure (Reichert ORA), contrast sensitivity (Sine Wave Contrast Test) and aberrometry (Tracey iTtrace). Data were analyzed using multivariate and partial correlation analyses.
Results:
Based on their floater scores and answers to the questionnaire subjects could be divided into three groups: 164 subjects with floaters (85.86%), 23 symptomatic subjects with floaters (12.04 %), and 4 subjects with significant floaters but few complaints (2.09%). Only 2 subjects (0.99%) did not have any floaters at all. Weak but significant partial correlations were found between floater score and age (Pearson r = 0.326), axial length (r = 0.144) and the spherical refraction (r = -0.15). No differences were found in the quantity and type of floaters present in symptomatic or non-symptomatic subjects, suggesting that other parameters might play a role (e.g. location of the floater along the optical axis).
Conclusions:
The proposed classification method permits objective grading of the type and amount of vitreous floaters, which may be a useful tool to select the most suitable treatment for each case. The presence of vitreous floaters does not automatically lead to floater related complaints. The floater score was found to increase slowly with age and axial length.
Keywords: 763 vitreous •
494 degenerations/dystrophies •
459 clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology