Surgical options for treatment of residual refractive errors after primary excimer laser refractive surgery
Alaa El-Din Taha Rabah Ershi;
Abstract
Nowadays, Excimer laser refractive surgery is considered the most common ophthalmic surgery after cataract extraction and IOL implantation. Excimer laser belongs to UV side oflight with a frequency wave 193[!m. Excimer laser refractive surgery includes PRK,LASIK, and LASEK.
Complications of excimer laser refractive surgery:
As numbers of these procedures increase, several complications have appeared. One of these complications is residual refractive errors. Residual refractive errors include undercorrection, overcorrection, regression, irregular astigmatism, and keratectasia.
I) Undercorrection & overcorrection:
It occurs when insufficient or exaggerated effect is obtained. The incidence ofundercorrection ranges from 15.2% to 79.3% and overcorrection ranges from 9.66% to 20.0%
2) Regression:
Regression means that refractive result of the primary excimer
laser surgery is not stable with continuous loss over time. The risk for regression is associated with higher attempted correction, and greater ablation depth.
Management a) Prevention:
Preoperative accurate assessment of refractive status, UCVA, BCVA, and
corneal thickness measurement.
b) Treatment:
1- Enhancement. 2-0ther surgical modalities.
1- ENHANCEMENT
Conventional technique:
This is further classi ficd into simple technique, and mixed technique. Simple technique means using the. same original procedure; PRK after primary PRK, LASIK after primary LASIK, LASEK after primary LASEK. Mixed technique means using another procedure; PRK after LASIK, LASIK after PRK, LASEK after LASIK
Nowadays, Excimer laser refractive surgery is considered the most common ophthalmic surgery after cataract extraction and IOL implantation. Excimer laser belongs to UV side oflight with a frequency wave 193[!m. Excimer laser refractive surgery includes PRK,LASIK, and LASEK.
Complications of excimer laser refractive surgery:
As numbers of these procedures increase, several complications have appeared. One of these complications is residual refractive errors. Residual refractive errors include undercorrection, overcorrection, regression, irregular astigmatism, and keratectasia.
I) Undercorrection & overcorrection:
It occurs when insufficient or exaggerated effect is obtained. The incidence ofundercorrection ranges from 15.2% to 79.3% and overcorrection ranges from 9.66% to 20.0%
2) Regression:
Regression means that refractive result of the primary excimer
laser surgery is not stable with continuous loss over time. The risk for regression is associated with higher attempted correction, and greater ablation depth.
Management a) Prevention:
Preoperative accurate assessment of refractive status, UCVA, BCVA, and
corneal thickness measurement.
b) Treatment:
1- Enhancement. 2-0ther surgical modalities.
1- ENHANCEMENT
Conventional technique:
This is further classi ficd into simple technique, and mixed technique. Simple technique means using the. same original procedure; PRK after primary PRK, LASIK after primary LASIK, LASEK after primary LASEK. Mixed technique means using another procedure; PRK after LASIK, LASIK after PRK, LASEK after LASIK
Complications of excimer laser refractive surgery:
As numbers of these procedures increase, several complications have appeared. One of these complications is residual refractive errors. Residual refractive errors include undercorrection, overcorrection, regression, irregular astigmatism, and keratectasia.
I) Undercorrection & overcorrection:
It occurs when insufficient or exaggerated effect is obtained. The incidence ofundercorrection ranges from 15.2% to 79.3% and overcorrection ranges from 9.66% to 20.0%
2) Regression:
Regression means that refractive result of the primary excimer
laser surgery is not stable with continuous loss over time. The risk for regression is associated with higher attempted correction, and greater ablation depth.
Management a) Prevention:
Preoperative accurate assessment of refractive status, UCVA, BCVA, and
corneal thickness measurement.
b) Treatment:
1- Enhancement. 2-0ther surgical modalities.
1- ENHANCEMENT
Conventional technique:
This is further classi ficd into simple technique, and mixed technique. Simple technique means using the. same original procedure; PRK after primary PRK, LASIK after primary LASIK, LASEK after primary LASEK. Mixed technique means using another procedure; PRK after LASIK, LASIK after PRK, LASEK after LASIK
Nowadays, Excimer laser refractive surgery is considered the most common ophthalmic surgery after cataract extraction and IOL implantation. Excimer laser belongs to UV side oflight with a frequency wave 193[!m. Excimer laser refractive surgery includes PRK,LASIK, and LASEK.
Complications of excimer laser refractive surgery:
As numbers of these procedures increase, several complications have appeared. One of these complications is residual refractive errors. Residual refractive errors include undercorrection, overcorrection, regression, irregular astigmatism, and keratectasia.
I) Undercorrection & overcorrection:
It occurs when insufficient or exaggerated effect is obtained. The incidence ofundercorrection ranges from 15.2% to 79.3% and overcorrection ranges from 9.66% to 20.0%
2) Regression:
Regression means that refractive result of the primary excimer
laser surgery is not stable with continuous loss over time. The risk for regression is associated with higher attempted correction, and greater ablation depth.
Management a) Prevention:
Preoperative accurate assessment of refractive status, UCVA, BCVA, and
corneal thickness measurement.
b) Treatment:
1- Enhancement. 2-0ther surgical modalities.
1- ENHANCEMENT
Conventional technique:
This is further classi ficd into simple technique, and mixed technique. Simple technique means using the. same original procedure; PRK after primary PRK, LASIK after primary LASIK, LASEK after primary LASEK. Mixed technique means using another procedure; PRK after LASIK, LASIK after PRK, LASEK after LASIK
Other data
| Title | Surgical options for treatment of residual refractive errors after primary excimer laser refractive surgery | Other Titles | الخيارات الجراحية لعلاج عيوب الانكسار المتبقية يعد عمليات اصلاحها بالليزر | Authors | Alaa El-Din Taha Rabah Ershi | Issue Date | 2006 |
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