The College of Optometrists

ok, i had a 32 yr old px today and it was a strange(ish) eye test.

she was last examined 2yrs ago, and her rx waS:

R) plano/-0.50 x 20

L) -0.75

her VA was 6/5 R&L.

unaided cover test result showed an isophoria, the left eye was 2 dioptres exophoric.

with her rx in place cover test showed the right eye to be 2 dioptres esophoric and the left eye to be 2 dioptres exophoric.

after ret and subjective i found her to be :

R) plano/-0.75 x 20 va 6/5

L) +1.50 va 6/5

and cover test with the new rx was 2 dioptres exophoric.

now the patient did come in complaining of headaches, so i assumed this may have something to do with the cover test results so have prescribed her the new rx and warned of adaptation. (everything else in the eye test was normal!)

anyone have any thoughts on this or is this pre reg year sending me loopy????

thanks xxxx

Very Strange!

But What I know is that in most anisometropic cases (especially where one eye is hypermetropic and the other one isn't) there will be a microtropia (small angle squint).

Now, Cover Test gives only one result and not two different for each eye.(they have to be identical no matter which eye you cover and test...Exophoria and esophoria will not coexist unless this patient has serious cranial nerve damage). I wonder whether your CT technique is up to scratch.

As you cover the right eye, the left eye accommodates by 1.50 driving convergence in the right eye, hence sop, when you cover the left eye, the right eye will not accommodate, and in fact is slightly myopic, so an exophoric movement is not that strange. so, by thinking about the different levels of accommodation when you cover each eye, it will help you to understand the results.

i disagree with biskiran, phorias need not be the same in each eye.

management: is the phoria compensated with rx? ie any FD, if it is fine, just prescribe the rx, if not, prescribe aligning prism aswell.

I agree with above but why has L gained so much plus? This is the bit where you have to make sure no pathology. It would be unusual to find one eye overminused this much without non tol, also what about history of lazy/weaker eye?

I would be looking very closely at macular area with volk.

ps did objective=subjective rx?

hey thanks it makes a bit more sense (ish), yeh, objective and subjective results were the same, so i did see that much plus movement in the left eye,the other issues that i was raising is that this may possibly be an accommodative spasm?? or latent hyperope?, i think i should cylo her and see what i find!