Real-world experience with the MFR2 IOL

Take-home message: Dr Thomassen shares his personal experiences with the MFR² IOL, including reasons why the MFR² is his lens of preference, clinical findings from a real-life setting and considerations for future use. 

By Dr Svein Erik Thomassen

Continuing developments in ophthalmic technology has resulted in an array of intraocular lenses (IOLs) which vary according to lens material, haptic design, incision size, diameter, spherical and spherical /cylindrical power. While access to a large bank of IOLs is clearly advantageous, selecting the most appropriate lens for a patient can be challenging.

In Denmark, however, ophthalmologists’ IOL options are somewhat limited by government guidelines. The Danish government stipulates that surgeons must use a hydrophobic, foldable IOL with aspheric optics. Additionally, the lens must be made from an acrylic material and have a 360° square edge. I also have my own preferences. Specifically, I prefer to not make wound-assisted injections and prefer to inject the IOL into the capsule as this permits a greater degree of control. The IOL material also should provide retinal protection and combine the positive features of hydrophobic and hydrophilic acrylic materials and should be insertable through a 2.2 mm incision

A new generation IOL: The MFR²

My quest for an IOL that met the demands of the Danish government and my personal preferences led me to the MFR² (Mediphacos Ltda, Belo Horizonte, Brazil).

The MFR² incorporates a plate haptic design that combines innovative design with implant stability and high clinical performance. Composed of a unique copolymer known as Flexacryl that combines hydrophobic and hydrophilic monomers, the MFR² can be supplied with a simple disposable injection system with a 2.2 mm incision size. It also has a 360° square edge and 6° haptic angle rests the optical body against the rear capsule, maximising the blocking effect of the square edge. The MFR² incorporates aspheric optics, developed using advanced RAY TRACING technology. The uniform optical power from the centre to the edge of the IOL provides excellent vision quality, better depth of focus and better optical performance if off-center.¹

Mediphacos also offers an IOL called the Miniflex, a conventional S-shaped single piece IOL - also made from Flexacryl. I used both lenses for a couple of months, but I found that when I injected through the same 1.8 mm tip, the MFR² had the least resistance in my hands and was superior to the Microflex in terms of ease of injection. Consequently, I decided to adopt the MFR².

Clinical Findings

I recently conducted a case series study which included 89 eyes of 89 cataract patients who were implanted with the MFR² at my private practice in Denmark. Preoperatively, all patients underwent an in-depth examination including high resolution ocular coherence tomography (OCT) and biometry (LENSTAR LS900, Haag-Streit AG, Koeniz, Switzerland) and measurement of best corrected visual acuity (BCVA). In each case, I implanted the MFR² IOL using a single 2.2 mm incision technique with the INFINITI Vision System (Alcon, Fortworth, Texas, USA). Postoperatively, all patients were treated with Tobradex (tobramycin + dexamethasone, Alcon) three times daily for two weeks and Yellox (bromfenac, Bausch & Lomb, Rochester, New York, USA) twice daily for six weeks. At one week postoperative, patients underwent a slit lamp examination, and intraocular pressure (IOP) and BCVA was measured. The same examinations were also performed at one month postoperative; patients also underwent a biometrical assessment at this follow-up visit.

An analysis of data from the first 89 eyes revealed that 76 patients had a minimum BCVA of 1.0 in the operated eye, eight patients had a BCVA of 0.8 to 1.0 and two eyes (one of whom had age-related macular degeneration [AMD]) had a BCVA of 0.5 to 0.8. An additional patient, also with AMD achieved a BCVA of 0.15, while a further two patients, one with atrophic AMD, and one with epiretinal fibrosis, had BCVAs of <0.04 and 0.15, respectively.

Overall, the MFR² was associated with few complications. A 58-year old patient experienced severe postoperative sterile uveitis diagnosed as toxic anterior segment syndrome. However, this was resolved with intracameral triamcinalone, and today, the patient has a BCVA of 1.0. A 77 year-old male patient developed cystoid macular oedema postoperatively and was treated according to European Society of Cataract and Refractive Surgeons guidelines. Today, he has a BCVA of 0.8. Complaints included colour disturbances, dysphotopsia and photophobia during the first three to four weeks postoperative. As expected, some patients reported that their floaters were clearer than before surgery. Overall patients were happy with their postoperative visual acuity. Of note, I did not have any difficulty with the injection procedure (even when implanting 28 D IOL) or placement of the IOL. Additionally, none of the lenses acquired any damage during the procedure.

Considerations

My patients and I are pleased with the performance of the MFR². However, I found that the lens was thin – reminiscent of the Akreos IOL from Bausch & Lomb and the OptiVis lens from Aaren Scientific (Ontario, Canada). Because of the thin material of the IOL, there are some theoretical considerations regarding stability.  For example, when I implanted a series of Aaren OptiVis multifocal IOLs, at follow-up, three eyes tended to go towards the plus side with 0.5 D per half year. A slit lamp examination showed that there was capsular contraction, which forced the optic in a posterior direction and bent the haptic up toward the iris. I have not encountered this with other, thicker multifocal IOLs. The problem was solved with careful YAG laser treatment of the contractile elements in the capsule, sometimes in combination with excimer laser touch-up when the IOL was considered to be in a stable phase. Consequently, a longer follow-up is required to determine whether the MFR² is stable in the capsule, and if capsular contraction will lead to IOL movement; six month follow-up data is currently being collated. Thus far, however, hyperopisation has not been reported with the MFR²

Going forward it will be interesting to see how the MFR² compares with other IOLs in terms of safety and efficacy. To this end, from January 2015, I will be participating in the one-year Alta study designed to compare stability and standard measurement outcomes (visual acuity, IOP, contrast sensitivity, OCT and biometry) of the MFR² with the AcrySof IQ (Alcon) in 200 cataract patients without existing ophthalmic pathology. In the meantime, the MFR² IOL continues to provide excellent outcomes, both in terms of safety and visual acuity, in my cataract patients.

References

1. MFR² - Mediphacos. http://www.mediphacos.com/en/produtos/catarata/lentes-intraoculares/MFR2/ Last accessed, November 10, 2014.

Dr Svein Erik Thomassen

E: sethomassen@gmail.com

Dr Svein Erik Thomassen is an ophthalmologist working in private practice at the Viborg Clinic, Viborg Denmark and Finnmark Eye Clinic in Norway.

Dr Thomassen states that he has no financial interests in Mediphacos Ltds.