Isotretinoin is a medication used to treat severe acne, and has some well known effects on the eye.
These include, with fairly high certainty, dry eye, Meibomian gland dysfunction, and a higher risk of styes/chalazia.
Other effects on the eye are less consistent with different results in different studies, or only small case reports describing a possible association.
These include poorer dark adaptation, possible effects on the retinal nerve fiber layer, one case report of central retinal vein occlusion etc
There is an association between isotretinoin and benign intracranial hypertension, which can cause swelling of the optic disc.
More specifically, isotretinoin has not been reported (to my knowledge) to increase the risk of retinal tears, which are the precursor to rhegmatogenous retinal detachments. Some small studies suggest they are associated with thinning of the retinal nerve fiber layer, but this in itself does not 'weaken' the retina or predispose it to tearing.
There are small case reports of isotretinoin use being associated with collections of serous subretinal fluid or central serous chorioretinopathy, but again this is not the same as the rhegmatogenous retinal detachment most people talk about.
Any effects isotretinoin has on the eye are probably not changed in any way by the degree of myopia present.
