eye doc questions.

questions i get asked every day. straight answers.

[eyedocquestions]

Why do I have to get my eyes dilated when I see the eye doctor?

By looking into your dilated eye we can see your lens, retina, retina blood vessels, and optic nerve. There are many conditions of the eye, as well as general medical conditions we can discover with a dilated exam.

Diabetes damage in the eye: People who have diabetes are at risk for eye disease that can cause vision loss or blindness.

Tumors: Brain tumors can often cause changes in the eye or vision problems.

High blood pressure: Damage to the eye’s blood vessels from hypertension could indicate a higher risk of stroke, especially for women.

Macular degeneration: This is the most common cause of blindness in older people, and catching it early can slow its progress.

Detached retina: A serious condition, it occurs when the retina separates from the back wall of the eye. To avoid vision loss, this must be repaired immediately.

Cataracts: The slow clouding of the eye’s lens makes it difficult to see, especially at night.

The most commonly used dilating drops last 4-5 hours.  During that time you might find bright lights bothersome, and it may affect your near vision.

[eyedocquestions]

Vision changes in pregnancy...

[eyedocquestions]

What's wrong with using Visine?

Many patients are surprised to hear their optometrist or ophthalmologist recommend against using Visine, or other similar eye drops such as Clear Eyes.  Why not?  They work don't they?

Yes, these drops take away the redness, which is why people use them, but they doesn't fix what's causing the redness.  Invariably the redness comes back, and you find yourself on the red-eye carousel with drops --> relief --> redness --> drops --> etc.  Some believe the "rebound" is worse than the initial redness.

The active ingredient in Visine is "tetrahydrozoline hydrochloride", which constricts blood vessels.  When applied to the eye, it causes the tiny blood vessels in the conjunctiva to constrict.  When the effect of the drug wears off, the blood vessels dilate again, giving the red appearance again.

But wouldn't it be better to target what is causing the blood vessel dilation in the first place?  But there are SO many reasons why your eyes may be red... including dryness, blepharitis, contact lens irritation, allergies, iritis, infection... if there is a question about the source of your eye irritation, it's best to see an eye specialist.  But there's no harm in trying some good, quality over-the-counter artificial tears, such as Genteal or Refresh, with some old-fashioned warm compresses to treat any existing blepharitis.

Visine and other vasoconstrictors are best used in moderation, a good rule of thumb is for no more than 3 days straight.

[eyedocquestions]

Should I get LASIK or PRK?

The most important thing to know is that the END results are the SAME. There are plenty of studies comparing visual results, and the two techniques are equivalent.

The following factors may influence your decision.  I subjectively put these in order of importance.

Recovery time (LASIK wins)

LASIK is faster.  LASIK is less painful.

PRK hurts, especially the first 3 days.

Remember the main difference in technique is flap (LASIK) versus no flap (PRK).  Think of the LASIK flap like moleskin covering a blister.  In PRK, there is no flap to cover the raw surface of the cornea that was just elegantly and precisely reshaped by the laser.

In LASIK your vision clears up very quickly, within a few days.  In PRK you've got to wait for your cornea surface to regrow, this can take a week.  Your vision will be blurry until this is complete.

Complications (slight edge: PRK)

Both can cause dry eyes, halos, glare, and light sensitivity.

LASIK-specific complications include: flap dislocation, infections and inflammation under the flap, abnormal cell growth at the flap interface, and a condition we ophthalmologists call ectasia.  Ectasia is when the cornea warps and thins out, simliar to a condition called keratoconus.  Thankfully, this is a very rare complication and are now very good at predicting which eyes are more likely to develop ectasia.  In these cases we recommend against LASIK in favor of other options.

PRK complications include: haze, infection, and inflammation.

Any of these complications can compromise vision.

Technique (slight edge: PRK)

LASIK video; PRK video

In LASIK, a flap needs to be created.  This accomplished either with a very precise blade or with a laser.  Either way, the eye needs to be firmly held immobile while the flap is made.  This is accomplished with a suction device the presses down on your eye... hard.  It's the most uncomfortable part of the procedure.  Luckily it's only for a few seconds, depending on the flap cutting technique.  This is an extra step that makes the entire process longer for LASIK than for PRK.

The criteria is a little more strict to be a candidate for LASIK.  Your eye doctor will put you through a battery of preliminary tests to decide which procedure you are a candidate for.

If you get LASIK you have to be comfortable with the idea of having a corneal flap.  There used to be more concerns that even long after the surgery, the flap could get traumatically dislodged.  In actuality, there are very few reported cases of this happening, and with the newer techniques this potential complication is extremely unlikely.  It's been deemed so safe, that LASIK has been approved by the U.S. Navy, even for SEALs and pilots.

My opinion is that if you're a candidate for LASIK, then go for it...  provided you have a good ophthalmologist with plenty of experience, and who does rigorous testing to make sure you are a good candidate.

Related eye doc questions:

what other options do I have besides LASIK and PRK?

what is the technology behind LASIK and PRK?

how much is LASIK and PRK?

can i get "retreated" after LASIK or PRK?

what's the deal with radial keratotomy?

[eyedocquestions]

how can i have 'dry eyes' when i'm tearing all the time?

                 Cause and effect.  When your eyes dry out from tear evaporation and air exposure, this triggers a reflex tearing response from the "tear maker" of the eye, the lacrimal gland.  This gland lives under your upper lid, and will give a robust but short-lived flow of tears, enough to overflow and drip down your cheeks.

Here's the crux of the problem:  the baseline tear production from this gland is barely a trickle.  So between reflex tearing episodes, the eyes dry out again, again triggering another vigorous response.

Patients, usually elderly patients with concurrent blepharitis (what's this again?) have trouble with the concept that if we treat their dry eyes, the tearing will improve.  The dry eye / tearing paradox.

[eyedocquestions]

eye sketch (via odosketch)

it's fun to draw on odosketch, check it out!

[eyedocquestions]

what's the difference between optometrists and ophthalmologists?

Grossly simplified:

optometrist = glasses, contacts

ophthalmologist = eye surgeon

Similarities:  Both perform full eye exams, prescribe glasses and contacts (although the optoms are typically better at this), both diagnose and treat a wide variety of eye conditions.

Differences:  ophthalmologists attend 4 years of medical school (therefore M.D.s or D.O.s), a 1 year internship, and a 3 year residency in ophthamology.  They see clinic but also perform surgeries on the eye, in the eye, and around the eye.  Typical eye surgery procedures include LASIK, PRK, Cataracts, blepharoplasties, injections, and laser procedures to the eyes.

[eyedocquestions]

how do you spell ophthalmology?

         If all ophthalmologists could agree on a simpler name, and one that distinguishes ourselves from optometrists, I think we would.

If you can remember to put 4 clashing consonants in a row, P-H-T-H, you can pretty much figure out the rest!  And it sounds like F-TH, as in "Hey get off-the grass"

Related:

What's the difference between an ophthalmologist and optometrist?

[eyedocquestions]

why is my vision blurry? the dry eye edition.

If you vision is intermittently blurry throughout the day, it's very likely to be related to dry eyes.  A healthy tear film covering the surface of your eye is essential to having clear vision!

Other clues your blurry vision is dryness related:

vision changes with each blink

dry, burning, or foreign body sensation

episodes of excessive tearing (how can tearing be related to dry eyes?)

Often coexisting with dry eye syndrome is the infamous blepharitis.

Try some *quality* artificial tears, see if this helps.  Good choices would be Genteal, or Refresh.  Use the artificial tears before or during certain activities, such as reading, using the computer, or watching TV.  We tend not to blink very much during these tasks, and the few tears we do make evaporate quickly.

Avoid ClearEyes and other similar drops designed to eliminate dry eyes.  (why don't eye docs like ClearEye?)

Mix in some healthy lid hygiene (what is lid hygiene?) and your eyes will thank you for it!

Slightly more advanced reading:

For such a simple diagnosis, "Dry Eye Syndrome" (DES) is actually quite complex.  Many factors are at play, such as tear production, inflammatory mediators in your tear film, tear evaporation, tear drainage, medication effects, etc...

A good eye doc will take a systematic approach to treatment.  We usually start simple with artificial tears, then on to non-preserved artificial tears.  I also like to offer eye ointments, especially before bedtime... it really helps to keep the corneas moist overnight, and particularly useful for those whos eyes really dry first thing in the morning (why does it hurt so much to open my eyes in the morning?).  

More advanced treatment can be given in the form of medicated eyedrops, including short courses of anti-inflammatory medicines, topical steroid drops, or an expensive eyedrop called Restasis. Eye docs can also place tiny silicone plugs into your tear drainage system to keep your tears around longer.