By Dr Waleed Al-Tuwairqi, MD Dr Omnia Sherif, MD Ophthalmology Consultants, Elite Medical & Surgical Center Riyadh -KSA Rome, Italy 2013
بسم الرحمن الرحيم In the name of Allah, Most Gracious, Most Merciful 2
Saudi Desert Riyadh Mecca Elite 3
4
In recent years, the technique of corneal collagen cross-linking (CXL) Revolutionized the management of Keratoconus. 5
Needs epithelial removal Does not correct refractive error Needs long time for UV exposure (30 min.) If combined with PRK, can give refractive surprises 6
LASIK is well established as the most commonly performed refractive surgical procedure. One of the most feared complications of LASIK is post operative ectasia. Hyperopic LASIK is associated with higher rate of regression compared to myopic LASIK 7
The combination of CXL therapy with the LASIK procedure has potential of ameliorating regression. Since corneal biomechanical response has been implicated in the patho-physiology of regression following hyperopic LASIK, modifying the corneal biomechanical properties might be beneficial. 8
Regression is a considerable clinical problem warranting retreatment in a significant proportion of cases and restricting the effective range of treatment. The concurrent use of CXL with LASIK may also allow treatment of a broader range of cases at risk of ectasia from LASIK alone. 9
In this study, we evaluated the refractive outcomes, safety, and efficacy of simultaneous LASIK and CXL in hyperopic cases & in KC suspects 10
Vast majority of cases requesting refractive surgery have normal topography & tomography and they are cleared easily for LASIK. Small group of patients requesting refractive surgery have an established diagnosis of KC. Another small group do not have enough criteria to confirm the diagnosis of KC (KC Suspect). Management of this group is controversial. 11
Ankylosing Spondylitis HLA-B27 12
No KC KC suspect E. KC F-LASIK ICL LASIK X PRK + CXL ICL ± CXL 13
KC suspect PRK LASIK X ICL 14
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Identify any additional risks or complications induced by CXL. Exclude any obvious effect of CXL on refractive outcome in hyperopic LASIK. Evaluate the possibility that the treatment modifies the occurrence of regression. Evaluate the possibility that the treatment can prevent ectasia in KC suspects. 16
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32 63 18
KC suspects (40 eyes) Hypermetrope (23 eyes) 19
All underwent FS LASIK technique with immediate CXL with: riboflavin application under the flap for 1 minute and 30 seconds followed by UV light irradiation, power of 3.6 j/cm2 for 1 minute and 30 seconds. Follow up was done on: 2nd day postoperatively 1 month postoperatively. 20
1. Mild superior inferior asymmetry of 1.5 3D 2. Coma >0.3 3. Anterior elevation <10µ Posterior elevation <15 4. Against the rule astigmatism with family history of KC 5. One case had a superior corneal scarring due to pannus and the topography was inconclusive. 21
Mean Minimum Maximum 25.95 ± 5.5 y 19 y 38 y Males 11 Females 9 Patients 20 Patients 20 Eyes 40 22
Compound myopic astigmatism Mixed astigmatism Simple astigmatism 37 eyes 2 eyes 1 eye 40 eyes 23
Mean average K 44.28 ± 1.89 Mean steep K Mean flat K 45.24 89 43.4 93 24
Mean Refraction -2.7-1.8 89 Mean corneal astigmatism -1.95 ± 1.29 Mean coma 0.25 ± 0.16 Mean thinnest pachymetry 514.75 µ ± 31.19 µ (468µ - 585µ) Mean maximum ablation depth 57.6 µ ± 18.5 µ Mean central ablation depth 56.85 µ ± 18.7 µ 25
Mean 0.21 ± 0.17 Minimum 0.05 Maximum 0.70 Mean 1.04 ± 0.15 Minimum 0.05 Maximum 1.20 Count 40 Eyes Count 40 Eyes 26
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Mean UCVA (Log Mar) Pre-Operative 2nd Day 1 M. 0.21 ± 0.17 0.87 ± 0.19 0.95 ± 0.17 28
1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.21 0.87 0.95 Mean Pre-Op 2 nd day Post-Op 1M. Post-Op 29
Mean BCVA (Log Mar) Pre-Operative 1 M. 1.04 ± 0.15 0.98 ± 0.09 30
1.05 1.04 1.03 1.02 1.01 1.00 0.99 0.98 0.97 0.96 0.95 1.04 0.98 Mean Pre-Op 1M. Post-Op 31
Mean Refraction Pre-Operative Post-Operative -2.7-1.8 89 +0.16-0.5 64 32
0.50 0.00 0.16-0.50-1.00-1.50-2.00 Mean -2.50-3.00 Pre-Op -2.70 1M. Post-Op 33
1.00 0.50 0.50 0.00-0.50-1.00 Mean -1.50-2.00 Pre-Op -1.80 1M. Post-Op 34
1. High hypermetropia beyond the LASIK limits with shallow anterior chamber or if pt. not interested in ICL 2. Preoperative assessment that raised the possibility of suboptimal outcome (based on a clinical composite determination of corneal thickness, topography and magnitude of refraction). 3. Hypermetropia and high astigmatism 35
Mean Minimum Maximum 24.7 ± 5.5 y 19 y 45 y Males 2 Females 10 Patients 12 Patients 12 Eyes 23 36
Compound hyperopic astigmatism 11 eyes Mixed astigmatism Simple hyperopia 10 eyes 2 eyes 37
Mean average K 41.87 ± 1.61 Mean steep K Mean flat K 42.95 86 40.78 111 38
Mean Refraction +3.4-1.8 109 Mean corneal astigmatism -2.17 ± 1.1 Mean coma 0.25 ± 0.07 Mean thinnest pachymetry 559.13 µ ± 31.3 µ (503µ - 596µ) Mean maximum ablation depth 63.64 µ ± 22.67 µ Mean central ablation depth 7.23 µ ± 9.5 µ 39
Mean 0.52 ± 0.20 Minimum 0.20 Maximum 0.90 Mean 0.97 ± 0.18 Minimum 0.04 Maximum 1.20 Count 23 Eyes Count 23 Eyes 40
Mean UCVA (Log Mar) Pre-Operative 2nd Day 1 M. 0.52 ± 0.20 0.87 ± 0.14 0.9 ± 0.11 41
1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.52 0.87 0.90 Mean Pre-Op 2 nd day Post-Op 1M. Post-Op 42
Mean BCVA (Log Mar) Pre-Operative 1 M. 1.04 ± 0.15 0.98 ±0.08 43
1.05 1.04 1.03 1.02 1.01 1.00 0.99 0.98 0.97 0.96 0.95 1.04 0.98 Mean Pre-Op 1M. Post-Op 44
Mean Refraction Pre-Operative Post-Operative +3.4-1.8 109-0.07-0.66 85 45
4.00 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00-0.50 Pre-Op 3.40-0.07 1M. Post-Op Mean 46
0.00-0.20-0.40-0.60-0.80-1.00-1.20-1.40-1.60-1.80-2.00 Pre-Op -1.80-0.66 1M. Post-Op Mean 47
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We had 5 cases with SPK (3 in the KC group) (2 in the hyperopic group). One case of DLK in the hyperopic group resolved within 1 month. One case of persistent CXL effect in the KC group resolved within 2 months. None of these complications affected the visual recovery. None of our patients lost any line of BCVA 49
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The primary finding in our study is that the addition of simultaneous CXL therapy to LASIK in hyperopic patients or KC suspects does not affect the safety of the procedure. There was no clinical or topographic evidence of flap-related complications. There was some early stromal haze (CXL effect), but this did not seem to significantly affect visual recovery and resolved within a month. Only one case persisted for 2 months but still did not limit the visual recovery. 51
Our study indicates that UCVA quickly reaches the target levels in both groups, without inducing any significant side effects or compromising visual safety. Group 1 Group 2 52
We found no significant over- or under-correction attributable to the combination of CXL and LASIK. There was also no suggestion of increased variability. No alteration of the regular LASIK treatment nomogram could be addressed in either group. Our goal is to minimize the risk of ectasia in the KC suspect cases and reduce risk of regression in hyperopic cases, so longer follow up periods are required for our patients to evaluate the incidence of long term adverse effects if any. 53
Saudi Desert Riyadh Mecca Elite 54