The College of Optometrists

What the difference between confrontation and perimetry??

and is it ok 2 use a 10mm red target (i kno in some books it says 15mm)

Also are patients to wear near Rx for the test(as the blurred image could affect the results)if so wat about varis and bif wearers? and due 2 the reduced aperture of the trial lens would make it difficult.

Whoz gona win Celeb big brother??

confrontation is a comparison between yours and px's visual field done in a flat plane halfway between you and the patient. (you need long arms to make sure the target comes from a non seeing area especially horizontally.

arc perimetry is done in an arc at a radius of 30cm from patients eye, you dont do a direct comparison with your own vf just judge areas where its is constricted

you can read more details about this in your text books

15mm red is quivalent to 5mm white (based on bjerrum targets) try to get as close to 15mm diameter as you can (or 5mm white of you cant find one)

This test is only for gross vf testing so blur wont have huge affect. unless v large RX do test without specs so no probs with lens artefacts. Trial frame reduced aperture lenses will definitely cause restricted field. dont use these.

I wanted Germiane to win Celeb BB, now shes gone Bez has got my support

just to add - I think the hair falling near the eyes is a bigger problem than the spex. Just to add an advert for the poor miss-aligned confrontation test - I work in a busy practice and lastyear, I detected 3 people with field defects on confrontation (I do it on everyone) that passed a central field plot (frequency doubling) - two had serious problems. One had a congruent field defect from possible stroke. One had a tumur that produced a small quadrantanopia and one had a long standing field defect from unknown cause who is now a subject at the exams for trainee ophthalmologists.

Where can I buy a red target and wand?

you can either make one out of paper mache and paint it red ! or i know that city university sell them... can remember how much for..probably two pounds i think ! xxx

a little red bead stuck on a knitting needle. Or even just a red pen.

and I have a little toy duck on a wand for kids - it flies arround for them to point at when they see it - very very handy!

red hatpin available from haberdashery stall in market, sewing notions to the uninitiated, mounted on piece of dowel painted black. different size hatpins are obtainable, but you may need to paint them

i still use confrontation, and find genuine defects, and have been in practice for 25 yrs, it does work!

and just a final point I do it on every kid I can.

Useful test and a requirement for the present PQE Routine exam. As such it should be "routine" and examiners tend to be able to tell if you have only done this test a couple of times before, so do it on all your patients before the exams. If you haven't yet got a target you are running out of time to practice this!

You can fail for poor confrontation in routine, especialy if you don't understand it's limitations and how it works.