title: Technical Note: A comparison of a novel direct ophthalmoscope, the Optyse, to conventional direct ophthalmoscopes.
abstract: Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use.
authors.affiliation: The Neville Chappell Research Clinic, The Institute of Optometry, 56-62 Newington Causeway, London SE1 6DS, UK. dharle@ioo.org.uk
authors.forename: Deacon E
authors.initials: DE
authors.lastname: Harle
authors.forename: Keri
authors.initials: K
authors.lastname: Davies
authors.forename: Rakhee
authors.initials: R
authors.lastname: Shah
authors.forename: Syma
authors.initials: S
authors.lastname: Hussain
authors.forename: Susan
authors.initials: S
authors.lastname: Cowling
authors.forename: Tejinder K
authors.initials: TK
authors.lastname: Panesar
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bourton
authors.forename: Bruce J W
authors.initials: BJ
authors.lastname: Evans
mesh_terms: D004867:Equipment Design; D005654:Fundus Oculi; D019721:Ophthalmoscopes