Refractive Surgery Program

Question 1

Define the role of the FS in the refractive surgery program.

Answer 1

Pre-op: Application, pre-surgical criteria

Post-op: DNIF, RTFS and waiver

Question 2

How much of refraction power is from the cornea?

Answer 2

2/3

Question 3

Describe where the image is focused in myopia, hyperopia and astigmatism.

Answer 3

Question 4

What is done to the cornea during refractive surgery in myopia, hyperopia, and astigmatism?

Answer 4

• Myopia– central cornea flattened
• Hyperopia– peripheral cornea flattened
• Astigmatism– asymetric treatment

Question 5

List the types of refractive surgery and give examples. What is PRK and LASIK classified as? Why do you need to know these?

Answer 5

• ASA (advanced surfce ablation)– PRK, Epi-LASIK, LASEK
• ISA (Intra-stromal ablation)– LASIK

Must know these as these are the only procedures approved for aircrew.

Question 6

Discuss refractive effect on presbyopia, particularly in relation to mild/moderate myopia.

Answer 6

CRS will not correct presbyopia.

Question 7

List 3 complications of CRS and their management.

Answer 7

1. Corneal haze– steroid drops and re-scrape epithelium
2. Striae ad microstriae
3. Flap dislocation (LASIK)

Question 8

Discuss altiude effects with PRK and LASIK.

Answer 8

• PRK– none
• LASIK– change in visual acuity reported in climbers

Question 9

How long are steroid eye drops required post-CRS? Why does this matter aeromedically?

Answer 9

• PRK– 2-4 months
• LASIK– 1 week

Required to be DNIF while on steroid eye drops. However, must be minimum of 1 month, even though off steroid drops earlier with LASIK.

Question 10

List 9 pre-surgical requirements for CRS.

Answer 10

1. > 6 months retainability
2. > age 21
3. Rx stability (< 0.50 diopter change over 1 yr)
4. Normal corneal topography (no kerataconus)
5. Adequate corneal thickness
6. Discontinue contacts
   
   1. SCL– 1 month prior (14 days for non-aircrew)
   2. Hard– 90 days
7. Contraindicated ophtho & systemic comorbidities
8. Not on contraindicated meds
9. 6-months post-pardum and not breastfeeding

Question 11

List refraction limits for CRS in myopia, hyperopia and astigmatism

Answer 11

• Myopia: -8.00
• Hyperopia: +3.00
• Astigmatism: 3.00

Must ensure that conversion calculations done

Question 12

What must aircrew have prior to CRS regardless of where the surgery is done?

Answer 12

Permission to Proceed

Question 13

When can aircrew RTFS?

Answer 13

Following MAJCOM waiver

Question 14

List 6 required exam items required for RTFS waiver.

Answer 14

1. 20/20 on OVT
2. 20/50 on Precision Vision 5% chart
3. OVT-DP
4. Refraction
5. Rx stability
6. Normal exam (slit lamp, DFE, IOP)

Question 16

What is the median RTFS time for PRK and LASIK? Why does this matter in AFSOC?

Answer 16

50% RTFS

• PRK @ 4 mo
• LASIK @ 3 mo

AFSOC deployment cycles are 90 days, therefore only approving LASIK

Question 17

Why is there concern about CRS at altiude?

Answer 17

Cornea is avascular. Gets oxygen from atmosphere.

Question 18

What causes the perceived halo following CRS?

Answer 18

The area of ablation is the area of good refraction. Light that comes in at edge is perceived as a halo. Incidence has decreased with increasing area of ablation zone.