Ophthalmology: Standards and Random Flashcards

1
Q

Service Group 1

A

Aviators qualified for unlimited or unrestricted flight duties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Service Group 2

A

Aviators restricted from shipboard aircrew duties (include V/ STOL) except helicopter

i.e., fixed wing carrier landings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Service Group 3

A

Aviators restricted to operating aircraft equipped with dual controls and accompanied on all flights by a pilot or copilot of Medical Service Group 1 or 2, qualified in the model of aircraft operated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Light passes through the 1 , 2 , 3 , 4 , and 5 before hitting the retina

A
  1. Tear film
  2. Cornea
  3. Anterior Chamber
  4. Lens
  5. Vitreous humor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Total refractive power of the eye

A

Approx 60 D

Note: roughly 44 D come from cornea and 16 D come from lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Standard eye length

A

24 mm

standard focal length = 16.7 mm (see below)

  • Remember: lens power = 1/f*
  • f = 1 / lens power (1/60D*) = 0.01666 m*
  • *Standard refractive power*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How thick is the cornea compared to the lens?

A

Cornea = 0.55mm

Lens = 4.5 - 5.5mm

BUT, the cornea still contributes more to refractive power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why does the Navy use minus cyl

A

…because Optometry “won”

Ophthalmologists will use (+) when documenting cyl (why some of the waiver guidelines fluctuate between -1 and +1)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

3 components of spectacle prescriptions

A

Sphere, Cyl, Axis*

*Axis from 001 - 180 (never negative or greater than 180)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Steepest meridian

A

aka the “most minus” meridian

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Transposition

A

Converting (+) cyl to (-) cyl Rx

    1. Add Sph and Cyl powers = new Sph value*
    1. Flip the sign of the cyl value*
    1. Change the axis by 90 deg*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Calculate Spherical Equivalence

A

Sph + 1/2 Cyl

Used on the refractive surgery AMS, and to “spot check” VA (-0.25 D of SE is approx 1 line of VA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Prism ____ to the deviation

A

points to the deviation

  • Note: light bends towards the BASE*
  • Ex. BI (Base In) = exo (aka prism pointing out)*
  • BO (Base Out) = eso*
  • BD (Base Down) = hyper*
  • BU (Base Up) = hypo*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DVA for SNA

A

Better than 20/40-0 and correctable to 20/20-0 on GoodLite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

DVA for all applicants except SNA

A

NO LIMIT for Uncorrected*

20/20-0 on Snellen OR 20/20-3 on AFVT or GoodLite

*Exception = Aircrew Applicant for rotary wing (must be better than 20<100, aka SG1 standards) and correct to 20/20-0 on Snellen or 20/20-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ref error for SNA vs SNFO

A

SNA: - 1.50 to + 3.00 (in any Meridian)

SNFO: < +/- 8.00 (all Meridians)

17
Q

Max Cylinder for SNA vs SNFO vs everyone else

A

SNA < 1.00 (or > -1.00)

SNFO < 3.00

Everyone else = no limit (to include rotary wing aircrew applicants)

18
Q

SNA and SNFO Anisometropia Limits

A

< 3.50 in any Meridian

No limit for any other applicant

19
Q

NVA for applicants

A

SNA must be better than 20/40 and correct to 20/20

Everyone else just needs to correct to 20/20*

Exception = rotary wing aircrew applicants (must be better than 20/100 and correct to 20/20)

20
Q

Other than SNAs, which other applicants have measured phoria limits?

A

UAV/UAS

Limits are:

< 6 eso/exo

< 1.5 hyper

21
Q

Color Vision Passing Score

PIP

CCVT (Waggoner)

CCT

A

PIP = 12/14

CCVT (Waggoner) = normal or mild

CCT (Rabin) = > 55 on all 3 cones in each eye

22
Q

Stereo is required for which applicants?

A
  1. SNA
  2. Rotary Wing Aircrew
  3. UAV/UAS
23
Q

Normal IOP

A

< 22 mmHg in each eye

Difference between eyes < 4 mmHg

If out of standards by NCT, retest with TAP

24
Q

Which stereo tests should be performed first (per NAMI)?

A

AFVT (A-D to pass)

and

Verhoeff (8/8 to pass)

If failed, Optometrist should test for Titmus or Randot (40 sec to pass) to ensure validity

25
Q

MWCLWF

A

Must Wear Corrective Lenses When Flying

26
Q

MWCLWF + CEP

A

Must Wear Corrective Lenses When Flying

+

Carry Extra Pair

27
Q

DDVA

A

Defective Distant Visual Acuity

28
Q

Pre-op refractive limits for applicants

A

Class I: +3.00 to -8.00 SE (spherical equivalents)

Class II-IV: +6.00 to -8.00 SE

3.00 D cylinder

3.50 D anisometropia

BOTH LASIK and PRK

29
Q

Pre-op refractive limits for designated personnel

A

Myopia: -11.50 SE with no more than 6D total cylinder

Hyperopia: +6.00 SE with no more than 6D total cylinder

ONLY FOR LASIK (no limits for PRK)

30
Q

For civilian applicants, the minimum time between surgery and flight physical eye exam is _____.

A

6 months

31
Q

Minimum time to flight following LASIK

A

Hyperopia < +4.00 SE = 4 weeks

Hyperopia > +4.00 SE = 8 weeks

Myopia = 2 weeks

32
Q

Minimum time to flight following PRK

A

Hyperopia = 6 months

Myopia < - 6.00 SE = 3 months

Myopia > - 6.00 SE = 6 months