Meeting News Coverage

Intraoperative anterior segment OCT accurately predicts IOL position after surgery

WARSAW, Poland — The use of continuous intraoperative optical coherence tomography provides an accurate prediction of IOL position after cataract surgery, leading to better refractive outcomes, according to one surgeon.

Nino Hirnschall

“About 60% of the refractive error depends on incorrect IOL positioning,” Nino Hirnschall, MD, said at the winter meeting of the European Society of Cataract and Refractive Surgeons.

A prototype Visante anterior segment OCT mounted on an OPMI VISU 200 operating microscope (Carl Zeiss Meditec) was used to perform continuous measurements of the anterior and posterior lens capsule position at different time points during cataract surgery. In all cases a capsular tension ring (CTR) was used to tighten the lens capsule.

“We also performed an ACMaster (Carl Zeiss Meditec) scan before surgery to measure the anterior chamber depth (ACD) in the phakic eye and compare it with the intraoperative OCT measurements. Partial least squares (PLS) regression was used to assess the influence of different pre- and intraoperatively measured parameters,” Hirnschall said.

Seventy eyes of 70 patients were included. Mean axial eye length was 23.6 mm (range: 20.6 mm to 30.8 mm), and mean IOL power used was 22.2D (range: 6 D to 31.5 D).

“PLS regression showed that the anterior lens capsule measured after removing the crystalline lens and after implanting a CTR was a significantly better predictor for the postoperative ACD compared to preoperative ACD measurements. The main problem of IOL power calculation, the prediction of the IOL position after surgery, could possibly be reduced by using intraoperative lens capsule measurements instead of preoperative ACD measurements,” Hirnschall said.

Disclosure: Hirnschall has no relevant financial disclosures

WARSAW, Poland — The use of continuous intraoperative optical coherence tomography provides an accurate prediction of IOL position after cataract surgery, leading to better refractive outcomes, according to one surgeon.

Nino Hirnschall

“About 60% of the refractive error depends on incorrect IOL positioning,” Nino Hirnschall, MD, said at the winter meeting of the European Society of Cataract and Refractive Surgeons.

A prototype Visante anterior segment OCT mounted on an OPMI VISU 200 operating microscope (Carl Zeiss Meditec) was used to perform continuous measurements of the anterior and posterior lens capsule position at different time points during cataract surgery. In all cases a capsular tension ring (CTR) was used to tighten the lens capsule.

“We also performed an ACMaster (Carl Zeiss Meditec) scan before surgery to measure the anterior chamber depth (ACD) in the phakic eye and compare it with the intraoperative OCT measurements. Partial least squares (PLS) regression was used to assess the influence of different pre- and intraoperatively measured parameters,” Hirnschall said.

Seventy eyes of 70 patients were included. Mean axial eye length was 23.6 mm (range: 20.6 mm to 30.8 mm), and mean IOL power used was 22.2D (range: 6 D to 31.5 D).

“PLS regression showed that the anterior lens capsule measured after removing the crystalline lens and after implanting a CTR was a significantly better predictor for the postoperative ACD compared to preoperative ACD measurements. The main problem of IOL power calculation, the prediction of the IOL position after surgery, could possibly be reduced by using intraoperative lens capsule measurements instead of preoperative ACD measurements,” Hirnschall said.

Disclosure: Hirnschall has no relevant financial disclosures

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