This article is more than 5 years old. Information may no longer be current.
Sizing important for phakic IOLs
Click Here to Manage Email Alerts
SAN FRANCISCO — Great care must be taken in sizing phakic IOLs considering the length of time they will remain in patients’ eyes, said a surgeon with experience with several models of phakic IOL.
VHF ultrasound and optical coherence tomography measurements of angle-to-angle and sulcus-to-sulcus distance provide a more precise estimate than do white-to-white measurements, said Carlo F. Lovisolo, MD, speaking here at the American Society for Cataract and Refractive Surgery meeting.
“It is completely unacceptable to me that we size a lens without knowing the exact measurements, especially when the lens is to be in place for 40 to 50 years,” Dr. Lovisolo said.
In the future, Dr. Lovisolo said he hopes to see phakic IOLs customized to individual patients. While acknowledging that day may be a long way away, he said for now surgeons should not be relying on the white-to-white external measurement technique alone.
“We have concluded that the white-to-white rule of thumb cannot be relied upon,” he said.
Dr. Lovisolo and associates conducted a study to assess the accuracy and predictability of different methods of choosing the overall length of anterior and posterior chamber phakic IOLs.
In total, four groups of patients were implanted with either angle-fixated lenses or STAAR posterior chamber ICLs. Two of the patient groups (20 eyes each) were sized using conventional sizing techniques based on external white-to-white measurements, including devices such as rulers, calipers and photographic techniques. The other two patient groups (30 eyes each) were implanted with the same types of lenses, but were sized based on information from newer technologies. These include very high frequency echography, optical coherence tomography and diode illumination.
The study found that the second two groups rated significantly higher in terms of vault predictability, and their complication rates were lower.
“It’s not just about sizing with expensive instrumentation, but in the future we should be moving toward ordering every phakic IOL on a customized basis to avoid complications down the line,” Dr. Lovisolo said.