A presentation by Samuel Khrapov on Laser Eye Surgery For Refractive Errors.

1. LASER EYE SURGERY
FOR REFRACTIVE
ERRORS
Samuel Khrapov
Avalon University School of
Medicine, Willemstad,
Curaçao

2. OBJECTIVE
The objective of this
research is to better
understand the surgical
procedures used to modify
the shape of the cornea and
its outcome on visual acuity
for refractive error

3. EYE
• Light sensitive
receptors are known as
rods and cones which
send electrical signals
to our brain through
the optic nerve[1]
• Rods= low light levels
• Cones= color vision
http://anatomyorgan.com/eye-diagram-for-kids/eye-diagram-for-kids-labeled-diagram-of-the-eye-and-
ear-diagram/

4. Hyperopia Myopia
http://www.intropsych.com/ch04-senses/04myopia.jpg
https://www.sciencelearn.org.nz/system/images/images/000/000/050/full/Converging-lens20150805-30610-9sjoqh.jpg?1447040428
https://www.sciencelearn.org.nz/system/images/images/000/000/051/full/Concave-lens20150805-30610-1o5y8hm.jpg?1447040428

5. https://i.ytimg.com/vi/Po7K0Va8BUs/maxresdefault.jpg

6. http://www.crizal.ca/userfiles/images/img-hyperopia.jpg

7. http://www.rebuildyourvision.com/wp-content/uploads/2013/04/Eye-Exercises-for-Astigmatism.jpg]

8. SNELLEN
CHART
https://www.maxiaids.com/Media/Thumbs/0001/00011
15-snellen-eye-chart.jpg

9. METHODS
•A systematic literature review
was completed after going
through EBSCO and PUBMED
•The data for over 600
procedures was observed
from FDA clinical trial
database of laser platforms,
laser companies, and
individual investigators [1,2,3]

10. PRE-
OPERATIVE
ASSESSMENT
• Patient History was noted for any
abnormalities such as glaucoma,
retinal detachment, ocular trauma,
and any other previous ocular
surgeries as they could greatly
affect the outcome of the
procedure[1,2,3]
• Careful refraction measurements
for refraction and corneal
curvature was taken to identify any
irregularities as well as
steepest/flattest corneal ridges[1,2,3]

11. PACHYMETRY
Central corneal thickness
http://c1-preview.prosites.com/34097/wy/images/Case%205%20refractive/Holladay%20Report%20OD.jpg

12. SURGICAL
PROCEDURE
•Microkeratome
https://i.ytimg.com/vi/lqajiJbULfI/maxresdefault.jpg

13. • Excimer laser- cold
ultraviolet light
• Myopia- the cornea is
flattened
• Hyperopia- the cornea
is made steeper
• Astigmatism- any
irregularities from the
cornea are removed
http://www.lasikeyesurgeryhawaii.com/wp-content/uploads/2013/04/Laser-Eye-Surgery.jpg

14. LASIK
SURGERY
RESULTS
94.5 90.7
73.9 73.1
2.1 0
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
Myopia Hyperopia
20/40 20/20 Decrease Visual Acuity

15. CONCLUSION
• As a result of LASIK surgery, millions
of individuals worldwide have reduced
their dependency on spectacles and
contact lenses.
• Improvements in laser design, eye-
tracking, and laser algorithms can all
be great improvements in the future
laser refractive surgeries.
• Using an excimer laser for corneal
tissue removal has been consistently
successful, while further research must
still be done on the role of wound
healing around the cornea flap.

16. REFERENCES
1. Chung B, Lee H, Choi B, Seo K, Kim E, Kim D et al.
Clinical Outcomes of an Optimized Prolate Ablation
Procedure for Correcting Residual Refractive Errors
Following Laser Surgery. Korean Journal of
Ophthalmology. 2017;31(1):16.
2. Sakimoto T, Rosenblatt M, Azar D. Laser eye
surgery for refractive errors. The Lancet.
2006;367(9520):1432-1447.
3. Seven I, Vahdati A, De Stefano V, Krueger R,
Dupps W. Comparison of Patient-Specific
Computational Modeling Predictions and Clinical
Outcomes of LASIK for Myopia. Investigative
Ophthalmology & Visual Science. 2016;57(14):6287.