Refractive Surgery COmplications Lecture 3

1. Refractive Surgery COmplicationsLecture 3 • Liana Al-Labadi, O.D.

2. Postoperative LASIK Complications 35

3. Postoperative PRK Complications 35

4. SIDE EFFECTS

5. SIDE EFFECTS

6. SIDE EFFECTS

7. SIDE EFFECTS

8. SIDE EFFECTS

9. SIDE EFFECTS

10. SIDE EFFECTS • Optical Aberrations: • Traditional objective refraction measures sphere, cylinder and axis (lower orders aberrations) • Ignores HOA such as coma, spherical aberration & quadrafoil • Effects of HOA on vision include: ghost images, haloes, shadows • Decrease optical quality • These effects are not compensated for with traditional spectacles & CLs • Optimal visual performance requires the simultaneous compensation of both lower and higher-order aberrations • Most likely eliminated with wave-front technology • DRY EYES: d/2: • conjunctival goblet cell damage / disruption of feedback loop from lacrimal gland to brainstem (neurotrophic theory) • cut corneal nerves ↓ sensitivity => ↓ CSF and optical quality

11. HOA- Different Views http://www.revoptom.com/content/d/ophthalmic_lenses___and___dispensary/c/15327/

12. SIDE EFFECTS • Dry Eyes: • Conjunctival goblet cell damage • Disruption of feedback loop from lacrimal gland to brainstem (Neurotrophic theory) • Cut K nerves ==> decreased K sensitivity --> decreased tear production = poor optical quality

13. SIDE EFFECTS • Night Vision Problems • Opt zone diam < pupil diam • Residual Rx / irregular astig => haloes and decr vision. • Often require night driving Rx starbursts Haloes

14. SIDE EFFECTS • Discomfort • First 24 hrs for LASIK • d/t speculum => orbital ache • Not as painful as PRK • Photophobia: • Related to optical quality and scattering, healing or haze • Conjunctival Heme • Application of suction ring

15. P.O. Clinical Implications for O.D. • 1. ↓ in BCVA • d/t irregular astigmatism & HOA which decreases optical quality • Optical quality is important for artists, architects, draftsmen who require good contrast sensitivity • Solution: • Eliminated with Wavefront guided ablations targeted beam - sent through eye - focused on retina. • Allows customized reshaping of cornea during refractive surgery procedure

16. P.O. Clinical Implications for O.D. • 2. ↓ NIGHT VISION • Residual Rx • Irregular astigm • Pupil diam > corrected optic zone diam • Solution: • Rx for driving • GP C/L • Miotic drops • Wavefront Rx

17. P.O. Clinical Implications for O.D. • 3. UNDERESTIMATION OF IOP • Appl tono => underestimates IOP • Flattened and thinned central cornea • Implication: Delay diagnosis of glaucoma • Solution:IOP’s > 17mmHG should be investigated further

18. P.O. Clinical Implications for O.D. • 4. DRY EYES • Conjunctival goblet cell damage • Disruption of feedback loop from lacrimal gland to brainstem • Implications: ↓ optical quality & discomfort • Solution: • Tear supplements • Punctal occlusion • Mild steroid/ Restasis

19. P.O. Clinical Implications for O.D. • 5. Corneal Ectasia • Bowing forward of post cornea thro weakened ant cornea • Implication: Astigmatism & keratoconus • Solution: • Monitor post-refractive surgery patients closely with K topography • Tx RE with GP C/L’s

20. P.O. Clinical Implications for O.D. • 6. DONOR CORNEAS • Post- refractive surgery corneas cannot be used for penetrating keratoplasty (corneal transplants) • Concern – negative impact on availability of donor corneas

21. Summary • Unbiased advise to make an informed decision • Requires practitioner education and familiarity with different aspects of refractive surgery • Interdisciplinary collaboration: pre-op, post-op management in conjunction with ophthalmologist • Research – long term effects remain unknown ??