1. Astigmatism “NO TOUCH” PROCEDURE
TransPRK (Transepithelial Photorefractive Keratectomy) For the Treatment of Low to Moderate Myopia with
Astigmatism “NO TOUCH” PROCEDURE
Presenting author Dr K V Satyamurthy, Dr Jaysheel V Nazare M.M.Joshi eye institte Hubli, India
Authors have no financial or proprietary interest in any material or methods

2. Introduction Transepithelial PRK
Most commonly indicated in eyes which cannot undergo
LASIK procedure due to inadequate corneal thickness
(estimated residual stromal thickness beneath the flap after the ablation would have
been less than 250 µm)
No corneal flap created
Both epithelium and stroma are ablated in single procedure,
decreasing overall treatment time and minimizing risk of
corneal dehydration.
PURPOSE OF STUDY
To evaluate efficacy of transepithelial Photorefractive
keratectomy (transPRK) for the treatment of low to
moderate myopia with astigmatism, using the Amaris
500 Hz laser platform.

3. METHODS Inclusion Criteria
Phakic patients with low to moderate myopia (-1.0 to -6.0 D of myopia with -1.0D to -4.0D astigmatism) Spherical
equivalent from -3.5 to -8D.
Healthy myopic patients 18 years or older.
Vision correctable to at least 20/20 bilaterally.
written informed consent form signed by patient.
Refractive status to be stable for at least 1 year.
Corneal pachymetry greater than 480µm. The estimated
residual Stromal thickness after ablation would have
been µm
Prior to preoperative evaluation, hard (PMMA) contact
lens discontinued for at least 3 weeks and soft lens
discontinued for at least 3 days.
Pupil diameter of equal or less than 7mm under scotopic
conditions.

4. Complete Ophthalmologic Examination
- Uncorrected (UDVA) and corrected (CDVA) distance visual
acuities
- Manifest and cycloplegic refractions
- slitlamp evaluation of the anterior segment and the fundus
- Applanation tonometry and tear-film assessment
Preoperative refractive workup included
- Combined Placido-Scheimpflug Imaging Based Topography
System (SIRIUS)
- Ultrasonic Pachymetry
Total of 29 subjects, were enrolled instudy.
Preoperatively,
- 0.25/0.5 mg of oral alprazolam.
- Topical drops of Proparacaine (0.5%) instilled in the eye to be treated
During procedure, epithelium and stroma were ablated in a
single step using transepithelial PRK nomogram of Amaris laser's
ORK-CAM software.

5. After ablation 0.02% Mitomycin-C solution applied 30
seconds.
- Cold BSS irrigation.
- High-O2 Content (59%) soft contact lens placed.
Ofloxacin (0.3%) and fluorometholone (0.1%) drops.
Post-operative Care and Follow-up
- Preservative-free artificial tears.
- Epithelial healing assessment on day 1and 3.
- CL removed once epithelium healed completely
- Fluorometholone drops tapered over 2-3 months.
At each follow-up visit (at1 week, at 1 month, and at 3 months) the UDVA, CDVA, and Corneal evaluation was done.
Haze grading using the Fantes et.al system
0 = no haze;
+0.5 = trace haze on oblique illumination;
+1.0 = corneal cloudiness not interfering with the
visibility of fine iris details;
+2.0 = mild effacement of fine iris details;
+3, +4 = details of the lens and iris not discernible.

6. RESULTS Parameters Values No of Patients 29 Age(yrs) Mean 24 Gender
- Male
- Female 13 16
Number of eyes
- Right
- Left 15 14

7. RESULTS Parameters Preop Post op 1month (p value) Post op 3month
Mean UDVA
(logMAR)
1.08
0.11(0.000)
- Mean Spherical
Equivalent

8. RESULTS Parameters Preop Postop 1month Postop 3month
Mean CCT (microns)
506
421(o.ooo)
424.9(0.000)
Mean SimK1 (D)
43.95
40.34(0.000)
40.43(0.000)
Mean SimK2 (D)
45.11
41.08(0.000)
41.16(0.0000
Mean Pupil (mm)
3.45
3.50(0.000)
3.67(0.007)

9. RESULTS Parameters Preop Postop 1month (p value) Postop 3month
Mean Thinnest pachy
503.5
418.7(0.000)
425(0.000)
Mean Thickness At Apex
529.8
590.7(0.000)
602.7(0.000)
Mean Cornea Volume
55.89
54.65(0.000)
54.76(0.000)
Mean LSA
1.02
2.26(0.000)
1.12(0.000)
Mean MPP
44.18
39.73(0.000)
39.52(0.000)
Parameters
Preop
Postop 1month
(p value)
Postop 3month
Mean SIF
0.10
0.15(0.000)
0.24(0.000)
Mean SIB
-0.03
-0.02(0.000)
-0.03(0.000)
Mean KVF
3.75
8.96(0.000)
9.17(0.000)
Mean KVB
12.79
16.75(0.000)
17.34(0.000)

10. RESULTS Parameters Preop Postop 1month (p value) Postop 3month
Mean BCVF
0.16
0.13(0.000)
0.24(0.000)
Mean BCVB
0.06
0.09 (0.000)
0.09(0.000)
Mean BCVT
0.1
0.11(0.000)
0.10(0.000)
Parameters
Mean Optical Zone(mm)
6.41
Mean Treatment Time (ablation)
42.58 s

11. RESULTS POST-OPERATIVE CORNEAL HAZE GRADES Total o 0.5 1 2 3-4 1 Month
24(82.75%)
5(17.24%) 29
3 Month
22(75.86 %)
7(24.13%)

12. CONCLUSION
Safety, predictability and efficacy of the Schwind Amaris advanced surface ablation nomogram(TransPRK) for the treatment of mild to moderate myopia with astigmatism in eyes with thinner corneas not suitable for LASIK procedure was found to be better than the existing alcohol assisted PRK technique.