Refractive surgery ans its use

1. CORRECTION OF MOST
COMMON REFRACTIVE
ERROR MYOPIA
Presented by: Purushotam Kumar Sahani

2. CONTENTS..
Myopia
Mechanism of production
Types of classification
Treatment

3. MYOPIA
-Short sightedness

4. Mechanism of production
Axial: 1mm, 3D
Curvatural: 1mm, 6D
Positional
Index
Accommodative

5. Types of classification
Clinical
classification
Degree of myopia Age of onset
Congenital Low (<3D) Youth-onset (<20yrs
of age)
Simple Medium (3-6D) Early adult onset
(20-40yrs of age)
Degenerative High (>6D) Late adult onset
(>40yrs of age)
Nocturnal
Pseudo
Induced

6. Treatment
1.Optical
-Spectacles (concave lens)
-Contact lens
-Orthokeratology (Upto -6D of myopia)
2.Surgical
-Epikeratophakia -Phakic IOL’S
-RK -LASIK
-PRK
-ICR

7. Epikeratophakia
-Done for Keratoconus, aphakia and high myopia
-Correct up to 20D of myopia
-Performed in aphackic patient

8. RK (Radial Keratotomy)
-Radial incision in peripheral part of cornea leaving the
central (4mm) zone
-After healing central zone is flattened
-Correct low to moderate myopia (-2 to -6D)

9. PRK (Photorefractive
keratectomy)
-Central stroma is photoablated using exicmer laser
(193nm UV flash) to flatten the central cornea
-Correction of -2 to -6D myopia
-Recovery period: The PRK procedure normally lasts
less than two minutes, but the healing period can take
from two days to over a week.

10. ICRS (Intra Corneal Ring
Segment Implantation)
-ICR implanted in to peripheral cornea 2/3rd
of stromal depth
-Flattening the central cornea
-Reversible
-Correct myopia upto -4.5D

11. Phakic IOL’S
Types:
-PCIOL
-Angle supported
-Iris claw lens

12. LASIK(Laser assisted in
situ keratomileusis)
-Advance form of laser
-Work on photoablation technique
-Excimer laser are used (193nm)
-It corrects -0.5 to -15D of myopia, 0.5 to 6D of hypermetropia
And 4D of astigmatism
-Recovery period: Many get their normal vision back within 24 to 48
hours.

13. Epi-LASIK
-Bladeless and painless laser vision correction
-Epithelium can be removed with an automated
polishing brush(soft brush), dilute alcohol solution or a
motorized instrument
-Procedure should be combined with wavefront
technology or slandered vision correction
-Recovery period: 1 week

14. LASEK(Laser-Assisted
Subepithelial Keratomileusis)
-combination of LASIK+PRK procedure
-Alcohol is used for 3o sec
-Corrects upto -10D of myopia
-Recovery period: 3-6 days

15. Pre-LASIK EXAMINATION
History Taking
Visual Acuity Testing
Refraction
Keratometry (measurement of corneal curvature)
Slit Lamp Examination
Pupillary measurements
Tear Film Analysis
Glaucoma Testing
Pachymetry (measurement of corneal thickness)
Detailed Retinal Evaluation with Dilatation.
Corneal Topography
FACT, LVCA (Low contrast Visual Acuity)
Aberrometry Test.(Schiner disc)
Pentacam Test

16. SELECTION OF PATIENTS
-Age above 18yrs
-Stable visual acuity
-Healthy eye
-Corneal scan has to be normal
-Not for pregenent women
-Not for more then age 40 yrs
-Limited refractive error selected

17. MECHANISM OF WORKING OF
REFRACTIVE SURGERY

18. PRESENTED BY:
Purushotam kumar sahani
Bsc optometry, 7th
sem
Vasan Institute Of Ophthalmology
and Research
Thanks,…….
Thank u all