The results of this retrospective study are similar in terms of mean gain in CDVA to those recorded in patients with monofocal IOL implants [18–21], thus mitigating one of the main concerns with respect to implantation of multifocal IOLs which is the rationale of this study and is consistent with the outcomes observed for multifocal IOL implants in eyes with other macular diseases, such as aged-related macular degeneration and diabetic retinopathy [12]. Our observation seems to be more associated with macular SD-OCT findings in the ellipsoid zone ( IS/OS junction) recovery, as observed and discussed by Inoue and Morita [6, 22].The mean UNVA results also improved significantly after the decrease recorded at diagnosis of ERM, which is also associated in our study with complete recovery of the ellipsoid zone. The decrease observed was based on comparison with eyes for which no recovery was recorded or recovery was only partial, although an acceptable UNVA was maintained in some of these eyes.
None of the surgeons reported any perioperative difficulty related to the design of the diffractive rings or lens, despite the data published by Yoshino and Inoue in 2010 [23], who reported visualization difficulties during PPV for ERM. However, it is important to note that the IOL model in that case was different (ZM900 ®; Abbott Medical Optics, Johnson and Johnson Vision, Santa Ana, California, USA).
Consistent with reports from other authors [18–21], the best mean CDVA results were obtained in eyes with better visual acuity before vitrectomy, with a p value of 0.024 between patients with a CDVA logMAR < 0.2 and those with a CDVA logMAR ≥ 0.2. This finding supports the indication of this procedure for symptomatic eyes diagnosed with ERM and good CDVA.
We did not observe any case of retinal detachment even though this complication has been reported after 1 year of follow-up in a large series of eyes with monofocal lenses (362 eyes) undergoing PPV for ERM (2.5%) by Guillaubey and Malvitte [24]. Inclusion of more cases in our study may have revealed cases of retinal detachment.
No significant myopic shift was observed in our study when SE after lensectomy was compared with SE after PPV, even when comparing eyes with or without sutured sclerotomies, thus explaining why no refractive adjustment after vitrectomy was required. In a similar study of 28 pseudophakic eyes with a monofocal IOL, Hamoudi and Kofod in 2013 observed a clearly significant myopic shift after PPV, although the follow–up period was 8.5 months [25]. In another review article, Hamoudi and La Cour reported different shifts in SE, even though other conditions and techniques were included [26].
In their pilot study, Patel et al. implanted a bifocal IOL (AcrySof IQ ReSTOR® SN6AD1; Alcon Laboratories, Inc., Fort Worth, TX, USA) during phacoemulsification combined with PPV in 6 eyes with cataract and ERM. The authors reported good visual and anatomical outcomes after only 3 months, despite using indocyanine green to stain [27]. Even though visual results with this trifocal IOL model are good, we do not consider its implantation when performing a combined procedure of phacoemulsification and PPV for ERM that could potentially work but involves a high risk of intolerance and may require explantation of the IOL. A safer option could be to perform the PPV for ERM and later on the phacoemulsification with a trifocal IOL implantation, once the macular recovery is complete.
Although this study is based on 20 eyes, to our knowledge, is the largest of this increasingly common indication to date, with a single trifocal IOL model. Despite this sample size is small, the data can endorse the purpose of this study, but further studies with bigger samples are needed to support it widely. One strength of the study is the long follow-up period (> 12 months) for all of the eyes included. Our study is limited by its retrospective design, the use of 3 different SD-OCT devices (because of potential interference with the CMT results), and the fact that surgery and follow-up involved more than 1 surgeon.