Purpose: To evaluate the early clinical outcomes of a new diffractive extended depth-of-focus (EDOF) intraocular lens (IOL). Methods: Prospective case series enrolling patients undergoing cataract surgery with implantation of the EDOF IOL AT LARA (Carl Zeiss Meditec, Jena, Germany). Distance, intermediate and near visual acuity were evaluated during a follow-up of 1 month. Likewise, defocus curve, binocular mesopic contrast sensitivity, perception of photic phenomena, patient satisfaction and spectacle independence were assessed. Results: The study enrolled 38 eyes of 19 patients with a mean age of 69.5 years. A significant reduction of manifest refraction and improvement in corrected distance visual acuity (CDVA) was observed with surgery (p < 0.001). All eyes achieved a 1-month postoperative binocular CDVA of 20/20 or better. Likewise, all eyes achieved a DCIVA of 20/30 or better at 1 month postoperatively, and a total of 92.1% achieved DCNVA of 20/40 or better. Concerning refractive predictability, 97.4% of eyes had a 1-month postoperative spherical equivalent within ±0.50 D. The level of patient satisfaction with distance, intermediate and near vision was high, with 95% of patients reporting that they would have the same surgical procedure with the same IOL again. Difficulties in night driving or associated to halos were low. A total of 89% of patients reported to be spectacle independent postoperatively. Conclusions: The EDOF IOL AT LARA is able to provide a functional restoration of the visual function across distances after cataract surgery, with very high levels of patient satisfaction and minimal incidence of photic phenomena.
In the last years, a new concept of presbyopia-correcting intraocular lenses (IOLs) has been developed and widely expanded in clinical practice, the extended depth of focus (EDOF) IOL technology [
The main basis of EDOF technology is the use of an optical design providing a more reduced near addition of the IOL while maintaining a continuous range of functional vision across intermediate and near distances. This can be achieved by means of a diffractive [
This prospective case series enrolled patients undergoing cataract surgery with implantation of the EDOF IOL AT LARA (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were cataract eyes with no comorbidity, availability, willingness and sufficient cognitive awareness to comply with examination procedures, and signed informed consent. Exclusion criteria were irregular astigmatism, corneal astigmatism of more than 1.00D, patient age below 40 years, difficulty for cooperation (distance from their home, general health condition), acute or chronic disease or illness that would increase risk or confound study results (e.g. diabetes mellitus with retinopathy, immunocompromised, glaucoma etc…), any ocular comorbidity, history of ocular trauma or prior ocular surgery including refractive procedures, capsule or zonular abnormalities that may affect postoperative centration or tilt of the lens (e.g. pseudoexfoliation syndrome, chronic Uveitis, Marfan’s syndrome), pupil abnormalities (non-reactive, tonic pupils, abnormally shaped pupils or pupils that do not dilate under mesopic/scotopic conditions), age-related macular degeneration (AMD) suspicious eyes, and/or complicated surgery. All patients were informed about the study and provided informed consent to undergo the clinical examinations in accordance with the tenets of the Declaration of Helsinki. The study received the approval of the local ethics committee.
All patients underwent a comprehensive preoperative ophthalmological examination including measurement of uncorrected and corrected distance visual acuity (UDVA and CDVA), keratometry, optical biometry (IOLMaster, Carl Zeiss Meditec AG, Germany), manifest refraction, biomicroscopy, Goldmann applanation tonometry, and dilated fundoscopy. Postoperatively, patients were evaluated the day after surgery, and at 1 week and 1 month after surgery. At these two postoperative visits, the following clinical tests were performed: measurement of monocular UDVA and CDVA, measurement of monocular distance-corrected near (DCNVA, 40 cm) and intermediate visual acuity (DCIVA) (80 cm), and manifest refraction. Likewise, at 1 month postoperatively, a monocular distance-corrected defocus curve was obtained in all cases, including levels of defocus from +2 to −4 D in steps of 0.50 D as well as a measurement of binocular contrast sensitivity under mesopic conditions with Functional Acuity Contrast Test charts (CST 1800 system, Vision Science Research). Patient satisfaction and quality of life were determined by means of a questionnaire, which was completed by the patients at the last follow-up visit. Questions included satisfaction about: adaption between photopic and mesopic conditions, ability to find the correct distance, night driving, vision during the day, halos, adaption between far and near vision and vice versa, as well as general satisfaction for distance, intermediate and near vision, and overall satisfaction. Patients were also asked whether they would perform the same surgery again and whether they need to wear glasses for the daily tasks. Each subscale score was converted to a score between 0 and 5, with higher scores indicating better results. Finally, halometry was also measured at this visit.
An experienced surgeon (FP) performed all surgeries using a standard technique of sutureless phacoemulsification. Topical anaesthesia was initially administered, and pharmacologic mydriasis was induced. Once pupillary dilation was achieved, the surgical procedure was initiated with a clear cornea microincision of around 2.2 mm with a diamond knife and a paracentes is 60˚ - 90˚ clockwise from the main incision. The IOL was implanted through the main incision using a specific injector. Postoperative pharmacological treatment consisted of a combination of antibiotic and steroidal anti-inflammatory drops. Likewise, non-steroidal anti-inflammatory drops were prescribed to prevent macular edema.
Data analysis was performed using the software SPSS for Windows version 19.0 (IBM, Armonk, NY, USA). Normality of data samples was evaluated by means of the Kolmogorov-Smirnov test. When parametric analysis was possible, the Student t test for paired data was used to compare the results between consecutive visits. When parametric analysis was not possible, the Wilcoxon test was used to compare the analyzed parameters between visits. For all statistical tests, a p-value of less than 0.05 was considered as statistically significant.
The sociodemographic and clinical characteristics of the patients is shown in
Parameter | Value |
---|---|
No. of patients | 19 |
No. of eyes | 38 |
Mean age/median age/age range | 69.5 ± 6.3 years; median: 69.0 years; range: 57 to 83 years |
Gender distribution | 7 males (36.8%); 12 females (63.2%) |
Mean preoperative axial length | 23.3 ± 0.9 mm; median: 23.3; range: 21.8 to 25.1 mm |
Mean preoperative anterior chamber depth | 2.9 ± 0.3 mm; median: 2.8; range: 2.5 to 3.5 mm |
Mean preoperative flattest keratometry | 43.1 ± 1.6 D; median: 43.0; range: 39.4 to 46.2 D |
Mean preoperative steepest keratometry | 43.8 ± 1.7 D; median: 43.6; range: 40.1 to 46.9 D |
Mean (SD) Median (Range) | ||||
---|---|---|---|---|
Preoperative | 1 week postop | 1 month postop | P-value | |
LogMAR UDVA | −−− | 0.09 (0.13) 0.03 (0.00 to 0.52) | 0.08 (0.10) 0.03 (−0.04 to 0.30) | --- |
LogMAR CDVA | 0.09 (0.10) 0.04 (0.00 to 0.38) | 0.02 (0.04) 0.00 (0.00 to 0.16) | 0.00 (0.02) 0.00 (−0.04 to 0.05) | <0.001 |
Sphere (D) | 1.73 (1.22) 1.75 (−1.75 to 4.00) | −0.17 (0.39) 0.00 (−1.00 to 0.75) | −0.17 (0.39) 0.00 (−1.00 to 0.75) | <0.001 |
Cylinder (D) | −0.78 (0.50) −0.75 (−1.75 to 0.00) | −0.20 (0.37) 0.00 (−1.25 to 0.00) | −0.16 (0.34) 0.00 (−1.00 to 0.00) | <0.001 |
SE (D) | 1.44 (1.11) 1.38 (−1.75 to 3.50) | −0.12 (0.32) 0.00 (−1.00 to 0.75) | −0.16 (0.39) 0.00 (−1.25 to 0.75) | <0.001 |
LogMAR DCNVA | −−− | 0.30 (0.09) 0.30 (0.00 to 0.50) | 0.30 (0.08) 0.30 (0.00 to 0.50) | --- |
LogMAR DCIVA | −−− | 0.14 (0.06) 0.10 (0.00 to 0.30) | 0.14 (0.07) 0.10 (0.00 to 0.30) | --- |
Categories | Mean (SD) Median (Range) |
---|---|
General satisfaction with distance vision | 4.7 (0.6) 5 (3 to 5) |
General satisfaction with near vision | 4.3 (0.7) 4 (3 to 5) |
General satisfaction with intermediate vision | 4.6 (0.7) 5 (3 to 5) |
Adaptation between photopic and mesopic conditions | 4.2 (1.0) 5 (2 to 5) |
Ability to find the correct distance | 4.9 (0.3) 5 (4 to 5) |
Night driving | 3.8 (0.8) 4 (3 to 5) |
Vision during the day | 4.7 (0.8) 5 (2 to 5) |
Difficulties associated to halos | 3.5 (1.2) 4 (1 to 5) |
Adaptation between distance and near visual acuity and vice versa | 4.4 (0.8) 5 (3 to 5) |
Overall satisfaction | 4.5 (0.8) 5 (2 to 5) |
patients reported that would have the same surgical procedure with the same IOL again. Likewise, and 89% (17) of the patients reported to be spectacle independent postoperatively.
This is one of the first clinical studies reporting the clinical outcomes obtained with the EDOF IOL AT LARA, which is based on a diffractive platform. Distance visual acuity is excellent with this EDOF IOL, with a 1-month postoperative UDVA and CDVA of 0.08 ± 0.10 and 0.00 ± 0.02, respectively. Therefore,
the diffractive platform of this EDOF IOL does not impair distance quality of vision, which is also reflected by the high levels of general satisfaction with distance vision. This is also consistent with the high mesopic contrast sensitivity measured postoperatively with this IOL, which is similar to that reported for patients implanted with monofocal IOLs [
Concerning intermediate vision, mean 1-month postoperative logMAR DCIVA (measured at 80 cm) was 0.14 ± 0.07, confirming the excellent performance of the EDOF IOL at intermediate vision. This was consistent with the high levels of general patient satisfaction with intermediate vision found in our study. A mean decimal UIVA of 0.80 was reported in the Concerto multicenter study evaluating the outcomes of the EDOF IOL Tecnis Symfony, with a median patient satisfaction score of 10.0 (scale, 0 to 10) [
All these visual outcomes were confirmed by the defocus curve that showed a very progressive decline of visual acuity when the level of negative defocus increased up to −2 D. The decrease of visual acuity is significantly more pronounced for defocus levels of more than 2 D. This shape of the defocus curve has been also reported for other types of EDOF IOLs [
The incidence of photic phenomena was minimal, with a median value of 4.0 each (scale, 0-worst situation to 5-best situation) in the patients’ evaluation of postoperative night driving and difficulties associated to halos. Likewise, a median value of 5.0(with the same scale) was obtained for the subjective patient evaluation of the postoperative adaption between photopic and mesopic conditions. This confirms one of the potential advantages of EDOF IOLs, the generation of less disturbing photic phenomena. Hamid and Sokwala [
The EDOF IOL AT LARA is able to provide a restoration of the visual function across distances after cataract surgery, with very high levels of patient satisfaction. The near visual performance obtained with this IOL is more limited than that obtained with multifocal IOLs, but it is within a functional range allowing the patient to perform most of the daily activities without the need for glasses. As expected according to the design of the IOL, the incidence of photic phenomena was minimal, with low impact on night driving. Future studies should confirm all these outcomes in larger samples over a longer follow-up period.
The study was supported by a research grant of Carl Zeiss Meditec.
Poyales, F., Garzón, N., Poyales, C. and Poyales, B. (2018) Clinical Outcomes with a New Model of Extended Depth of Focus Intraocular Lens. Open Journal of Ophthalmology, 8, 161-170. https://doi.org/10.4236/ojoph.2018.83020