A novel extended-depth-of-focus (EDOF) IOL (Mini WELL IOL, SIFI Medtech) is providing very favorable functional and safety outcomes that correspond with a high degree of patient satisfaction, according to data collected by ophthalmologists at the University Eye Clinic Heidelberg.
"We are finding that patients implanted with the Mini WELL IOL have excellent uncorrected visual acuity at far and intermediate distances along with very good uncorrected near visual acuity and a very low incidence of photic phenomenon," said Ramin Khoramnia, MD, assistant professor of ophthalmology, University of Heidelberg, and head, Refractive Surgery Department, University Eye Clinic, Heidelberg, Germany.
The lens is a biconvex multifocal aspherical IOL with a progressive optic featuring three zones. The central zone and a surrounding annular zone have spherical aberrations of opposite signs that create a continuous number of foci, and the external zone is a basic monofocal zone.
"The Mini WELL IOL provides quite sharp images at far and intermediate distances and near image quality is also quite good. In contrast, standard bifocal IOLs provide sharp images at far and near distances, but variable quality images at intermediate distance," said Dr. Khoramnia.
Dr. Khoramnia reviewed outcomes achieved at 3 months postsurgery by patients enrolled in a prospective non-randomized study conducted at the University Eye Clinic Heidelberg. Gerd U. Auffarth, MD, PhD, professor and chairman, Department of Ophthalmology, University of Heidelberg, is the principal investigator of the study
The analysis included data from 40 eyes of 24 patients. Their preoperative median SE was 0.50 D (range -7.75 to 4.88 D).
At 3 months, mean corrected distance visual acuity (CDVA) was 0.00 logMAR, mean distance-corrected intermediate VA measured at 80 cm was 0.04 logMAR, and mean distance corrected near VA was 0.22 logMAR.
"Defocus curves for the Mini WELL IOL also show that it provides good visual acuity over quite a large range," Dr. Khoramnia said.
Functional near vision was also assessed through evaluation of reading performance using the Salzburg reading desk.
"We think it is very important to objectively evaluate the reading performance with presbyopia-correcting IOLs because many patients do not read at the distance that is used in clinical studies to test near visual acuity," Dr. Khoramnia explained. "The Salzburg reading desk calculates reading acuity while continuously measuring reading distance and speed as patients do the reading task at their preferred distance."
The results showed the IOL provided excellent intermediate vision and also performed well at near. Median binocular uncorrected intermediate VA was 0.11 logMAR and median binocular uncorrected near VA was 0.13 logMAR.
Reading performance in patients implanted with the IOL was also investigated in the FOCUS multicenter trial in which the Heidelberg center participated. Radner reading charts were used in the FOCUS trial, and the data collected showed that about 92% of patients were able to read 0.5 logRAD print (book letter size) at a rate of at least 80 words per minute.
Minimizing photic phenomena
Photic phenomena in patients implanted with the IOL were assessed using a proprietary halo and glare simulator. With this device, patients view a night-driving scene and indicate whether they see any halo or glare around lights, the type of these phenomena as well as their size and intensity. The data can then be converted to numerical values for statistical analysis.
Preliminary results showed that about 50% of patients implanted with the IOL experienced no glare or halos at all while affected patients had only minimal problems with the photic phenomena.
"Looking at the data for the patients who reported the maximum values indicates that they did not experience much bother from glare and halos," Dr. Khoramnia said.
Ramin Khoramnia, MD
The International Vision Correction Research Centre at the University Eye Clinic Heidelberg receives funding support from SIFI.