Secondary Logo

Journal Logo

Institutional members access full text with Ovid®

The Optical Functional Advantages of an Intraocular Low-Vision Telescope


Optometry and Vision Science: April 2002 - Volume 79 - Issue 4 - p 225-233

An implantable miniaturized telescope (IMT) for low vision has recently been developed. Surgically inserted into only one eye of patients with bilateral central visual loss, the IMT provides a nominal magnification of 3.0× and a field-of-view of 6.6° (9.2° for the 2.2× magnification version). Theoretical concerns have been raised regarding the ability of patients to function with a large interocular magnification difference, the impact of the monocular restriction of the field-of-view, and the impact of this design on depth perception. This article addresses these concerns regarding the design of the IMT in comparison with spectacle-mounted telescopes and combined intraocular lens/spectacle (or combined contact lens/spectacle) telescopic systems. The effective field-of-view (as determined by the combination of both the field-of-view and the field-of-fixation), the effects of head motion and the vestibular reflex, and the disruption of stereo depth perception with a monocular device are considered here. Physiological optics considerations of these issues show that the IMT may have important advantages over other designs of magnification devices for patients with age-related macular degeneration.

The Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts

Received October 3, 2001;

revision received December 14, 2001.

Eli Peli

The Schepens Eye Research Institute

20 Staniford St.

Boston, Massachusetts 02114


© 2002 American Academy of Optometry