Two-year results with Centerflex look promising

By Ana Hidalgo-Simon MD

SUSSEX, UK - The new Centerflex™ IOL (Rayner) held its own in a comparison study of four types of foldable lenses. The new lens can be implanted through an incision as small as 2.85 mm.

Ashok Vyas MD, from the Scarborough Hospital, UK, presented the two-year results of the Scarborough study at a Rayner seminar.

The randomised, prospective Scarborough study compared the SI 30 NB (silicone, hydrophobic), MA30BA Acrysof® (acrylic, hydrophobic), IOLTECH Stabibag (hybrid acrylic, hydrophilic) and Centerflex 570H (hybrid acrylic, hydrophilic). Each type of lens was implanted in 40 eyes.

All patients were subjected to routine phacoemulsification, through a clear cornea tunnel incision of between 1.25 mm and 1.75 mm length.
The incision was enlarged to 3.5 mm except in the case of eyes implanted with Centerflex, which required up to a 3.00 mm wound.

The IOLs were placed in the bag. Patients were examined on a slit lamp one day, one week, three weeks and three months after the operation and then followed for two years.

Patients were aged between 50 and 90 years, and implant power ranged from 16 D to 26 D.

"We did not include patients with previous intraocular surgery, diabetes or Pseudoexfoliation syndrome because we wanted to analyse the lenses' performance under the best possible conditions," Dr Vyas explained.

All of the lenses produced good visual acuity. Some 97% of patients achieved 6/12 or better at two years. Age-related macular degeneration was the main reason for worse than 6/12 acuity in all lenses. Patients more frequently reported glare, reflections and dazzle with Acrysof implants at three months. These effects were rare after two years with any of the lenses.

Pigments were observed most frequently with silicone lenses, seen in more than 80% of patients. That value was significantly higher than the other three types of lenses at three months, one year and two years.

At two years, Stabibag had the lowest score, with less than 5% of patients presenting visible pigments on the lens.

"We also looked at forceps marks on the lens. Here, Acrysof lenses performed the worst, with nearly 45% of lenses presenting marks after two years. Stabibag and Centerflex did not show marks at two years. We also looked for the presence of glistening and specks. The silicone and Acrysof lenses scored poorly, but Stabibag and Centerflex were very clear," Dr Vyas observed.


Lowest decentration rate with Centerflex
Moderate decentration (0.5 mm to 1.00 mm) occurred in 20% to 35% of patients implanted with silicone, Acrysof and Stabibag at three months, one year and two years. The rate for Centerflex remained around 10%. Gross decentration (over 1.00 mm) was not observed in any Centerflex implant, but 20% or more was found in silicone lens implants and in around 10% or more of Acrysof and Stabibag implants over the three periods of time studied.

Slit-lamp examinations for any visible axial and para-axial fibrosis showed a rate of around 10% in silicone lenses at three months. This increased at one and two years to around 15%. Acrysof and Stabibag presented no fibrosis at three months, but 8% to 10% of patients with those lenses showed some fibrosis at two years.
No axial fibrosis was visible on slit lamp examination in Centerflex-implanted patients at any time point.

Para-axial fibrosis was more frequently observed in patients implanted with Stabibag (10% to 20% for three months and two years respectively). Some 15% of silicone lenses showed para-axial fibrosis. Very little fibrosis (under 5%) was seen with Acrysof and none with Centerflex.

Slit lamp examinations were also used for any visible axial and para-axial epithelium. Centerflex showed the highest amount of visible axial epithelium, with 20% of patients presenting at three months and increasing to 35% at two years. This was significantly higher than the other three lenses studied. No significant differences were found in para-axial epithelium, with Stabibag presenting slightly higher scores than the other three lenses at every time point.

YAG capsulotomy
By two years, YAG capsulotomy was performed in around 15% of patients implanted with silicone lenses and about 20% of patients implanted with Stabibag and Centerflex. YAG capsulotomy was not required in any patient implanted with Acrysof. Reduced capsulorrhexis size was only seen in silicone lens implants. This was present from the first observation time point at three months. Mean anterior chamber depth did not show significant differences at two years.
Implanting the lenses

"We asked the surgeons for their subjective opinion on how difficult it was to perform the implants. Mounting difficulties were reported more frequently with Acrysof (more than 35%), and were very low with silicone and Centerflex. Inserting difficulties were also high with Acrysof (nearly 50%) and very low with the other lenses," Dr Vyas explained.

The Scarborough study will continue for another two years, in order to accumulate four years of follow-up data.
"We are very excited about the possibilities for this new lens. In a separate study, we found a very high level of patient satisfaction (97% satisfied or highly satisfied) and minimal dysphotopsia.

"It is the implant of choice at Scarborough hospital because it can be injected through an unenlarged small incision and has shown superb centration, minimal fibrosis of posterior capsule, minimal dysphotopsia and minimal vaulting. It stays clear and has shown very good biocompatibility at two years," Dr Vyas said.

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