Just finished a week of tutorials at the new eye clinic in Manchester. During this we discussed when to use an Amsler grid. As low-tech as this is, it is still easy for patients to understand for self monitoring and is a useful indicator of central distortion. The list of indications for its use we came up with was as follows;
- if the macula looks anything other than acceptable on ophthalmoscopy
- if there is any report at all of central vision changes
- if there is any unexplainable reduction in acuity.
Less significant might be the need to assess the central red field if a patient is using a maculopathic inducing drug like tamoxifen. Another symptom that sometimes indicates macular problems is where there is a reduced photostress recovery time. I have had patients concerned that, having had a photo taken at a wedding, they have noticed the purple after-image for a long time afterwards - cue the Amsler.
Reduced acuity at the end of the refraction usually warrants use of the pinhole. If there is any residual refractive element (or in some cases where there is light scatter from a cataract) the pinhole may show some improvement in acuity and warrant further refractive assessment. Early maculopathy may result in a reduced pinhole acuity however and therefore again be worth getting the Amsler out for.
Are there any other times for using the Amsler? Or does anyone out there have any experience of the PHP, an automated attempt to assess central distortion?
Which rather long-windedly brings me round to the subject of pinhole spectacles. I have been told that Optician has now carried a Google ad on its website for pinhole glasses. Not the most responsible of recommendations though probably enough to allow anyone to pass the current driving test! I genuinely worry that it is only a matter of time before there are adverts for small bags of sand to be placed on the closed lids to remove the need for myopia spectacles. In fact, tell patients to screw up their eyelids and do away with any form of glasses!!! Our feet are riddled with bullets.