An update on Centerflex® following the ESCRS meeting in Amsterdam

On Friday 31st August, 2001, a Centerflex® users’ meeting was held prior to the ESCRS Congress in Amsterdam, The Netherlands. This proved to be a both very enjoyable and highly informative meeting with valuable contributions being made by several eminent guest speakers. Presentations were given by Professor M. Amon (Vienna, Austria), Dr. G. Auffarth (Heidelberg, Germany), Mr. A. Vyas (Scarborough, UK), Dr. L. Vargas (Charleston, USA) and Professor D. Apple (Charleston, USA).

Professor Amon and Dr. Auffarth, who are part of the multi-centre Centerflex® study group, reported very positively on their results to date. Of particular interest were their favourable comments on the overall stability of Centerflex® and in particular, the rotational stability. This proven stability for the Centerflex® design, which is due entirely to the performance of the uniquely designed haptics incorporating AVH technology, gives Centerflex® the “edge” in terms of dioptric accuracy. This has been clearly demonstrated by Messrs. Percival, Bacon and Vyas (Scarborough, UK) and is reported elsewhere in this update.

Professor Amon and Dr. Auffarth also reported very little evidence of cellular activity (post-implantation), and although they said it was too soon to comment on PCO, they reported no laser capsulotomies to date. Professor Amon pointed out that many researchers have, in the past, referred to the theory that some hydrophilic lenses may be “too biocompatible”. This is a contradiction in terms when the definition of biocompatibility is described as being the “ability of a material to co-exist in harmony with the host, with no deleterious effect on the host tissue”. The inference being that if a lens is too biocompatible, then it may permit cellular activity. The exact opposite was shown to be true, in that the less biocompatible materials, eg. silicones, actually stimulate cellular proliferation. Mr. Vyas reported excellent visual outcomes from the Scarborough (UK) group with excellent dioptric accuracy, significantly better than the European standard, with no evidence of PCO, very little pigmentary deposition and no calcification.

He also discussed a paper (co-written with Percival and Manvikar), Incidence of Dysphotopsia from a square edged hydrophilic lens. This paper shows that Centerflex® is associated with a low incidence of unwanted optical imagery (dysphotopsia) even though it has a square edge. He discussed the design features which contribute to these excellent results, such as a lower refractive index, a good optic design and configuration (equiconvexity) and accurate centration.

Dr. Vargas, who is a member of Professor Apple’s team at The Storm Eye Institute, Charleston, South Carolina (USA) presented a recent paper in which PCO was investigated. He reported an excellent result for Centerflex® with significantly less PCO than for a single-piece hydrophobic lens and a plate haptic silicone lens. He also demonstrated superb stability for Centerflex® and remarked on the instability of the single-piece hydrophobic lens indicating a severe design flaw. The highlight of the meeting was Professor Apple’s presentation during which he made the following very positive observations for Centerflex®.

1. The square truncated optic edge is efficacious in helping reduce PCO.
2. The hydrophilic optic surface is very efficacious in reducing silicone oil adherence.
3. Centerflex® does not require a haptic-optic angulation, a significant advantage in facilitating lens insertion.
4. The Rayner injector is one of the easiest and most comfortable ones he has tried.
5. Centerflex® is highly biocompatible with NO evidence of calcification of any form.
6. Centerflex® does not evoke significant fibrotic change, therefore it may reduce such complications as cictrization-induced decentration or capsular phimosis.

Professor Apple also reiterated the 6 factors he considers to be so important in the reduction of PCO and these are:-

A. Surgery-related factors
1. Hydrodissection-enhanced cortical clean-up. 
2. In-the-bag fixation. 
3. Small capsulorhexis with the edge on the IOL surface to sequester the capsular bag around the IOL optic.

B. IOL-related factors
4. Biocompatible material to reduce stimulation of cellular proliferation. 
5. Maximal IOL optic/posterior capsule contact, angulated haptic, and adhesive biomaterial. 
6. IOL geometry to offer a square, truncated edge.