More on PRK

Thank you to all ODs and friend who support me with their feedback, yes
it just didn't sink in well with me to get the PRK with this
prescription. Military OD at Hawaii who would perform the surgery denied
to do so. I got the email. I am not that upset but I have some concerns,
I'd appreciate some feedback.

He said* "Sorry, but we have decided not to do refractions this low.
Our cut off is a -1.50 spherical equivalent. The results on anything
below this usually are not worthwhile and sometimes the risk is greater
than the benefit."
*
This is what I was thinking after I read your responses. Though, what
does "spherical equivalent" mean? My concern is my right eye which is
-0.75 + 0.25 x40 now, the flight pyhsical consists of "transposing"
these numbers and standards must meet in both plus-cylinder and
minus-cylinder formats, after that calculation, my right eye seems to be
-1.00 -0.25 x130(?) according to military technical bulletin. This
leaves me only half a diopter room before I would be disqualified for
flight duty. If my eye moves another half diopter and transposed numbers
equal a -1.50, can I be still eligible for PRK? Maybe that is what
spherical equivalent?

I will write more later... Thanks a lot... By the way, Bill, my right
eye was 20/30-1 and pin hole 20/20-2 and left was with moisturizing
drops 20/20. This exam was at 1430 hours so my eyes were not so fresh as
some call it. I wonder if the acuity results would be different if it
was done 0900 in the morning.

Dear John,

I wonder if you could check something
for me.

I have been told that you must read
4 out of 5 characters to pass the line.

Dr Judy says that reading 1/2 the
characters pass the line.

(I like Judy's standard.)

Question: Is there any standard?

Best,

Otis

*ATB - DISTANT VISUAL ACUITY TESTING
(DD Form 2808, Block 61. 'DISTANT VISION') [As of: 1 May 2002]*

- IMPORTANT NOTE ABOUT 20/20 DISTANT VISUAL ACUITY
STANDARD FOR FDMEs! Per AR 40-501, paragraph 4-12, a (1),
"...no more than 1 error per 5 presentations of 20/20 letters, in
any combination, on either the Armed Forces Vision Tester
(AFVT) or any projected Snellen chart set for 20 feet."
- Issue: AFVT line has 10 letters but is split into two sets of five letters
positioned next to each other on the same line. You may still test the
entire line, if desired, but the patient is still only required to get
*4 out
of 5* letters that are on a 20/20 line to be considered a 'pass' for an
FDME. Therefore, entries of 20/20 or 20/20-1 are both passing entries.
Most projected Snellen charts have 6 letters (some have 4, 5, 7, or 8
letters) per line. The regulation allows for presentation of 5 letters "in
any combination" so you may meet the requirement. If in que stion,
refer to the Eye Clinic for verification.

Mike Tyner wrote:

>
>Very logical.
>
>Spherical equivalent is the mean dioptric power, the average of the two
>major meridians.
>
>For -0.75+0.25x040, the SE is -0.62. When you convert, honor the signs.
>
>Your myopia would have to double before it threatens your qualification. And
>the later myopia begins, the milder it tends to be.
>
>-MT
>

Mike, Can you help me find where I am standing according to Army regs?
Let me quote the standard procedures for the Army exam...

UPDATED ENTRY STANDARDS FOR CLASS 1/1A FLIGHT DUTY MEDICAL EXAMINATIONS.
(as of 28 March 2002):


Hyperopia greater than +3.00 diopters of sphere (in any meridian by
transposition in either eye)
Myopia greater than -1.50 diopters of sphere (in any meridian by
transposition in either eye)
Astigmatism greater than +/- 1.00 diopter of cylinder in either eye
Must meet above standards in both plus-cylinder and minus-cylinder
formats, so transpose to ensure patient meets standards
(spherical equivalent method does not apply).

For example, the cycloplegic refraction of:
-1.00 - 0.75 x 180 (in minus-cylinder format)
might appear qualified at first glance. However, after transposition
into plus-cylinder format of:
-1.75 + 0.75 x 090 (in plus-cylinder format)
it is apparent that this refraction is disqualifying because the sphere
amount exceeds -1.50.

Transposition Review:
1. Algebraically sum the sphere and cylinder powers
2. Change the sign of the cylinder power
3. Change the axis by 90 degrees.

Important Note for Eye Care Providers
A cycloplegic refraction is NOT necessarily equal to the refraction you
would give for spectacle lenses. If a patient is "on the
border" of being qualified or disqualified, it is best for the Army and
for the patient to use the "least amount of prescription
needed to see within standards" approach.
For example, if a patient has a cycloplegic refraction that is +/- 0.25
diopters outside of standard but can still read to the
20/20-1 standard with the refraction amount that is WITHIN standards,
enter the lesser amount.
Do NOT, however, try to "push" the 20/20-1 on borderline cases. These
patients receive an entirely new cycloplegic exam
once they come to Fort Rucker to enter flight school. If they are
outside of the standard, they will be required to request an
exception-to-policy which will likely be disapproved. Use your
professional judgement but do not allow someone to come to
flight school knowing he/she has a good chance of failing their detailed
cycloplegic exam upon arrival.

So what is mine after this transposition? As far as I understood, they
are not doing the spherical eq. for flight duty exams.

Thanks...

Mike Tyner wrote:

>If your script was written -075+025x030, that transposes to -050-025x120.
>
>Either way, you're in.
>
>-MT
>
Thank you, this is good to know...

What is the K's 43.75 @087 44.5@095 also on my paperwork?

Mike Tyner wrote:

>Keratometry is a measurement of the shape of your cornea. It's used mostly
>for fitting rigid contacts, but it's included as a formality sometimes.
>
Oh I see, do these numbers seem like anything out of the ordinary or
pretty normal? I couldn't find anything on these in the Army regs, so
they must not be of any criteria. Thanks again Mike.