ASCRS San Diego May 2001

Suggested Nidek hyperopic settings: Profile 5, PMMA ro cornea 0.85 and sph/cyl 0.4. 34 Hz and +3 should take 45 to 48 secs calibration time for 9mm zone.

Atopic patients should have oral antihistamines pre and post-op lasik and/or steroid drops of oral steroids as they have a higher risk of DLK.

Hyperthermia for long-standing striae. Heat spatula to 65 C and massage at right angles to striae. Repeat 10-15 times. Do both sides of flap. Bandage cl. Up to 2/12 to settle done. Transepithelial PTK for persistent striae over the peaks. Or scrape of this "tenting" epithelium.

Rosacea patients have a higher risk of epitheliopathy with lasik- they have an abnormal tear composition. Treat pre-op with oral tetracycline and topical steroid.

Striae can be re-positioned at the slit lamp with a cotton wool bud up to 5 mins post op.

Lasik can cause PED, bleeding and acute visual loss. If there is drusen, beware!

34% have mild dry eye with Hansatome and 23% severe (Calgary - very dry). Plug often!. Wait 6/12 before re-Rx for hyperopia. Nidek has 0.5D regression from 1st to 6 month post op and 0.9 D over 12 months. Don't go more than 49-50D for hyperopia,, otherwise you are creating a sort of keratoconus. Similarly, 36D is minimum for myopia post op. (John Hill). Apical SPK can be a problem with H-LASIK.

Hyperopia - angle kappa increases as hyperopia increases. Best not to do greater than +3 and centre on the pupil

Topography: If the posterior float is >40 microns, suspect subclinical KCN and don't do lasik. Also, if superior to inferior "hot spot" difference is > 30 microns depth difference, suspect the same.

Residual depth less than 280 microns seems to be a risk factor for keratectasia. Peripheral cornea gets 20 microns thicker after flap cutting because of lamellar retraction.

Normal cornea is +0.5 prolate

SD of Jack Holladay is 0.38D for his results.

Winter ESCRS Meeting Cannes Feb 2001