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Filed Under
Cataract
Refractive
post-refractive surgery
refractive outcomes
intraoperative aberrometry
intraoperative wavefront aberrometry
IOL power calculation
Barrett formula
2020 paper presentation
Purpose
To compare accuracy of current intraocular lens (IOL) power calculation formulas with intraoperative wavefront aberrometry (ORA) in eyes with previous hyperopic and myopic advanced surface ablation surgery (LASIK/PRK)
Methods
Retrospective review of eyes with history of hyperopic or myopic ablation who underwent phacoemulsification between April 2015 and September 2019. All eyes underwent pre-operative optical biometry using the IOLMaster® and intraoperative biometry using ORA. IOL power was calculated using the Barrett-True K formula for post-hyperopic and post-myopic ablation. Comparison between ORA-recommended, Barrett-True K recommended, and IOL implanted was conducted. The error in the predicted refraction was calculated as the difference between the actual postoperative refractive outcome and the predicted refraction for each formula or method. A group of nonrefractive eyes was used as control.
Results
48 eyes with previous hyperopic ablation, 50 eyes with history of myopic ablation and 62 controls were included in this study. In the hyperopic group, the lowest mean prediction error (PE) was observed with the ORA-recommended IOL (0.03±0.57), compared to IOL implanted (0.108±0.65), and Barrett-True K (0.396±0.63; p=0.03). In the myopic group, the highest mean PE was observed with Barrett-True-K formula (0.46±0.79), followed by ORA-recommended (0.061±0.48) and IOL implanted (0.06±0.48; p=0.001). In the control group, no statistically significant difference was seen in IOL calculations using Barrett Universal II (-0.01±0.66) and ORA (-0.06±0.77; p=0.69).
Conclusion
Intraoperative biometry may be an important tool to improve postoperative refractive outcomes in patients post-hyperopic or post-myopic advanced laser ablation, whereas in normal eyes, standard IOL calculation using Barrett Universal II yields good refractive outcomes.
To compare accuracy of current intraocular lens (IOL) power calculation formulas with intraoperative wavefront aberrometry (ORA) in eyes with previous hyperopic and myopic advanced surface ablation surgery (LASIK/PRK)
Methods
Retrospective review of eyes with history of hyperopic or myopic ablation who underwent phacoemulsification between April 2015 and September 2019. All eyes underwent pre-operative optical biometry using the IOLMaster® and intraoperative biometry using ORA. IOL power was calculated using the Barrett-True K formula for post-hyperopic and post-myopic ablation. Comparison between ORA-recommended, Barrett-True K recommended, and IOL implanted was conducted. The error in the predicted refraction was calculated as the difference between the actual postoperative refractive outcome and the predicted refraction for each formula or method. A group of nonrefractive eyes was used as control.
Results
48 eyes with previous hyperopic ablation, 50 eyes with history of myopic ablation and 62 controls were included in this study. In the hyperopic group, the lowest mean prediction error (PE) was observed with the ORA-recommended IOL (0.03±0.57), compared to IOL implanted (0.108±0.65), and Barrett-True K (0.396±0.63; p=0.03). In the myopic group, the highest mean PE was observed with Barrett-True-K formula (0.46±0.79), followed by ORA-recommended (0.061±0.48) and IOL implanted (0.06±0.48; p=0.001). In the control group, no statistically significant difference was seen in IOL calculations using Barrett Universal II (-0.01±0.66) and ORA (-0.06±0.77; p=0.69).
Conclusion
Intraoperative biometry may be an important tool to improve postoperative refractive outcomes in patients post-hyperopic or post-myopic advanced laser ablation, whereas in normal eyes, standard IOL calculation using Barrett Universal II yields good refractive outcomes.
View More Presentations from this Session
This presentation is from the session "SPS-110 Post Refractive Surgery - IOL Calculations" from the 2020 ASCRS Virtual Annual Meeting held on May 16-17, 2020.