Using Peripheral Vision with Macular Disease and Low Vision Rehabilitation

 

 







Patient with an Inferior Preferred Retinal Locus
 

Patients with macular disease and central field loss with apparently identical pathology can exhibit very different levels of visual impairments.  These patients often adopt an eccentric preferred retinal locus (PRL).  The term “preferred retinal locus” describes a retinal area that acts as a pseudofovea by providing better vision than the diseased fovea/macula. 

While a PRL appears to naturally develop in patients experiencing a central scotoma without formal training, the ability to use this non-foveal area varies widely.

Eccentric viewing (EV) describes fixation in which the eye moves off center as to place the image of an object outside the fovea.   There is a science and art to eccentric view training (EVT).  Preferred retinal locus and eccentric viewing are important components for successful low vision rehabilitation.

Scanning laser ophthalmoscope macular perimetry can be used to find the PRL relative to the fovea.  The Fletcher Central Field Test using a red laser pen appears to be an effective test when an SLO is not available.

During the course of the disease, the location of the patient’s PRL may change.  The PRL appears to be task specific and more than one PRL can be used by a patient.  Research continues to gather data on this topic.

Unanswered Questions:

1.      What factors determine the patient’s section of the PRL location?

2.      Why do some patients seem to develop a functional PRL and others do not?

3.      Can a PRL be taught?

4.      Does the PRL match the patient’s best acuity area?

5.      How does the placement of the PRL impact reading ability?

6.      Can an eccentric PRL favorable for effective reading be established through a trained retinal locus (TRL)?

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