Increased Axial Length Corresponds to Decreased Retinal Light Dose: A Parsimonious Explanation for Decreasing AMD Risk in Myopia.

Purpose: A recent systematic review indicated that higher sunlight exposure increased risk of AMD. The Beaver Dam study and the Pathologies Oculaires Liées à L'âge study both noted that wearing hats and/or sunglasses significantly decrease some AMD lesions, suggesting that reduced retinal light dose (RLD) may be related to reduced AMD risk. Given that myopes also have reduced AMD risk, we hypothesize its link to decreased RLD.

Comparing optic nerve-head-size measurements by the heidelberg retina tomograph with fundus photography performed with a novel focusing technique.

Purpose: To compare disc areas as measured with the Heidelberg Retina Tomograph (HRT) to those obtained with a fundus camera.

Design: A nonrandomized comparative trial.

Participants: Forty-six patients (88 eyes) who were participating in a glaucoma-screening study.

A new fundus camera technique to help calculate eye-camera magnification: a rapid means to measure disc size.

Objective: To find a simple means for calculating eye-camera magnification to permit estimation of true retinal object size from a retinal photograph.

Methods: The position of the focusing knob on 3 different retinal cameras (TRC-50F and TRC-50X; Topcon America Corp, Paramus, NJ; and the CR6-45NM Non-mydriatic Retinal Camera; Canon Inc, Tokyo, Japan) was measured during optic nerve photography and correlated with the refractive error, or spectacle refraction, of the subject (N = 11 for each camera).

Results: A strong correlation was found between focusing knob position and spectacle refraction for each of the 3 cameras tested (r = 0.