glare/blurriness in one eye, days at a time

I have several conditions that might be relevant to the health of my eye:

* Type 2 diabetes, with pretty good control (last A1c was 6.2)
* High myopia (around -9 in each eye)
* Epithelial basement membrane dystrophy (recurrent corneal erosions a decade ago, resulting in a bit of corneal scarring but no ongoing problems -- I still use Muro ointment nightly, and Genteal drops during the day as I've been told I have some dryness)
* Posterior subcapsular cataracts, apparently growing slowly since they're not causing major problems five years after diagnosis.  I do have some glare in my right eye, which has the more centrally located cataract, but it does not cause undue difficulty.

My problem is that, with increasing frequency, I'm having episodes where my right eye suddenly gets much worse.  I'll wake up one day to find the haze and glare are much more bothersome than usual, to the point where I can't read a street sign if it's backlit by a bright sky.  It's hard to read my computer screen for the haziness.  It's like there's oil smeared on my glasses.  My vision seems somewhat blurred, though would say the haziness is much more marked than the blurriness.  Increasing my eye drops doesn't make any difference.  All of this lasts for about four days, then slowly goes away over the course of an evening.  

This has happened five times in the last eight months, and now episodes are coming about a month apart.  I have regular dilated eye exams, and I had one during an episode in June; the doctor said my vision seemed okay since I could read the 20/25 line on the chart, and suggested that it was either a blood sugar fluctuation or dry eye.  That's the point at which I started the Genteal.  The blood sugar explanation seemed unlikely to me since I don't recall the episodes being preceded by unusually high readings, and it seems odd to me that blood-sugar-related fluctuation would always and only (a) affect one eye and (b) last for four days.  

Last week, while my vision was normal, I was examined by a cornea and lens specialist.  She also thought that the changes could be blood sugar related, though my blood sugar numbers have been good.  She also suggested that perhaps I was simply noticing the cataract more under certain lighting conditions (which does not seem to fit with discrete incidents lasting 3-4 days).  I asked if she thought it would be useful for me to return while I was having problems, so she could examine me again, but all she said was that they could refract me for new glasses at that point if I wanted.  That does not sound particularly useful or relevant, since my glasses are fine.

I am at a loss.  I've been warned with my history of nearsightedness to come in immediately if I have sudden changes in vision, but what I'm reporting doesn't seem to concern anybody.  From what I've read about blood-sugar-related vision fluctuations, they sound like they tend to affect both eyes, and to be more frequent and variable than what I'm seeing.  What would my next step be?  What sorts of eye problems can cause symptoms for a few days in just one eye and then improve -- swelling somewhere?  Should I be checked by a retinal specialist next time, though no doctor has found any retinal issues yet?  Looking for possibilities online, I've seen speculative stuff ranging from optic nerve problems to multiple sclerosis. I'm not about to jump to any conclusions, but I have no idea where the logical place to start narrowing it down is -- and I have a doctor who seems inclined to shrug it off.  But I'm the one who finds myself closing my right eye when I want to read a sign in the grocery store, and that doesn't seem like the kind of thing one safely ignores.  Any ideas?  

[John C Hagan III, MD, FACS, FAAO]

The episodic nature of your complaints is not typical of cataracts, not usally ant mem dystrophy.

I suggest you see a neuroophthalologist rather than retina Eye MD.  Find one near you at www.aao.org or ask your eye MD to refer you.

JCH MD