Elsevier

Ophthalmology

Volume 112, Issue 9, September 2005, Pages 1579-1585
Ophthalmology

Original article
Preferred Retinal Locus Development in Patients with Macular Disease

Portions of this work presented at: Association for Research in Vision and Ophthalmology Annual Meeting, April, 2004; Fort Lauderdale, Florida.
https://doi.org/10.1016/j.ophtha.2005.03.027Get rights and content

Objective

To observe the development of the preferred retinal locus (PRL) in a group of patients with central scotomas caused by recent onset macular disease (MD).

Design

Prospective observational case series.

Participants

Twenty-five individuals with bilateral central scotomas caused by MD. All patients had experienced visual loss in their better eye in the 2 weeks before recruitment.

Methods

Patients were assessed at baseline and at 4 further visits for up to 12 months. At each visit, the retinal area used for fixation was assessed using a scanning laser ophthalmoscope, the infrared Gazetracker was used to determine the number of discrete retinal areas used for fixation in 5 positions of gaze, and reading speed was measured using MN-Read–style sentences.

Results

All 25 patients developed a PRL within 6 months. Sixteen patients (64%) made an adaptation whereby they were unaware of using an eccentric retinal area for fixation. Multiple fixation loci were exhibited by 11 patients at the end of the study. Nineteen patients used a consistent number of PRLs under all positions of gaze. Reading speed was not associated with PRL location or the presence of multiple PRLs.

Conclusions

All of the patients in this study developed a repeatable preferred retinal locus within 6 months of visual loss in their second affected eye. Reading performance was better in patients who were not aware of using eccentric viewing strategies and who used a repeatable number of PRLs under all positions of gaze. These findings are relevant for counseling patients with MD and for the design of rehabilitation programs for patients with central vision loss.

Section snippets

Patient Selection

Patients were recruited from the Medical Retina, Accident & Emergency and Low Vision clinics at Moorfields Eye Hospital, London. Eligible patients reported vision loss in their second affected eye in the 2 weeks before recruitment, which was confirmed by examination of visual acuity (VA) and comparison with previous notes made in the patient record. Patients had a primary diagnosis of AMD, Stargardt’s disease, or Best’s disease and had no ocular comorbidity other than visually insignificant

Patients and Length of Follow-up

Fifteen patients with exudative AMD, 5 with geographic AMD, 4 with Stargardt’s disease, and 1 with Best’s disease were recruited into the study. Eighteen of the 25 patients completed 12 months of follow-up and 7 were removed earlier: 6 after 6 months and 1 after 3 months. In 6 of these patients, the reason for exclusion was an enlargement of the scotoma, whereas 1 patient experienced a severe deterioration in her general health.

Location of the Principal Preferred Retinal Locus

The location of the principal PRL at the baseline assessment for

Discussion

This study used a novel longitudinal strategy to describe the development of the PRL for a group of MD patients with recent vision loss in their better eye. In all of the patients, a repeatable retinal area for fixation developed within 6 months, with half of the patients using their final PRL location at the first assessment (that is, within 1 month of scotoma development). Although it is possible that some of these patients will make further adaptations in the years after their scotoma

Acknowledgment

The authors thank Glen Harding for calibrating the power of the scanning laser ophthalmoscope.

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  • Cited by (0)

    Manuscript no. 2004-174.

    Supported by the Guide Dogs for the Blind Association, Reading, United Kingdom (Ophthalmic Research Grant no.: 2000-29a [MDC]), and the European Commission, Brussels, Belgium (grant no.: QLRT-2002-00214 [GSR]).

    The authors have no financial interest in any of the techniques or equipment described in the article.

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