Abstract
Purpose :
To determine the relative outward radial forces of various commercially-available hydrophobic acrylic intraocular lenses (IOLs) under common degrees of compression relative to an available capsular tension ring (CTR).
Methods :
Ten representative samples of commercially-available IOLs (MX60 (Bausch & Lomb), MX60E (Bausch & Lomb), ZCB00 (Johnson & Johnson)) in addition to an equivalent sampling of a single variety of CTR (CTR10, FortifEYE, Bausch & Lomb) were placed in an compression force apparatus in their wet state. Outward radial forces were averaged across IOLs and CTRs tested using scenarios that mimic the physiologic range of capsular bag sizes (9.5, 10.0, 10.5, 11.0mm). Mid-powered IOLs (MX60: 20.0-20.5D, MX60E:20.0D, ZCB00: 14.0-26.0D) and a CTR with dimensions that fall within geometry being tested (uncompressed: 12.3mm, compressed: 10.0mm) were evaluated.
Results :
The average radial outward compression forces observed were: at 11.0mm (MX60=0.021, MX60E=0.021, ZCB00=0.032, CTR10=0.121 gf), at 10.5mm (MX60=0.037, MX60E=0.040, ZCB00=0.041, CTR10=0.157 gf), at 10mm (MX60=0.094, MX60E=0.095, ZCB00=0.058, CTR10=0.176 gf), at 9.5mm (MX60=0.120, MX60E =0.091, ZCB00=0.078, CTR10=0.229 gf), and at 9.0mm (MX60=0.114, MX60E=0.114, ZCB00=0.103, CTR10=0.266 gf).
Conclusions :
All varieties of IOLs and CTRs tested showed a trend towards a linear relationship between outward radial force and degree of compression, with the CTR averaging 316% more outward radial forces relative to average of the IOL group. MX60E demonstrated the highest outward radial force of all IOLs at 10mm (0.095 gf); 21.14% greater than ZCB00 and 54% of the total force of a CTR under similar conditions. Both MX60 and MX60E demonstrated greater capacity to direct compressive forces outward relative to ZCB00 with increasing degrees of compression (@9.5mm: MX60: +18.42%, MX60E: +5.86%; @9.0mm: MX60: +4.02%, MX60E: +4.09%). ZCB00 exhibited a propensity to deliver more outward force in the largest well configurations tested (@ 11mm: MX60: -9.06%, MX60E: -9.30%; @10.5mm: MX60: -3.13%, MX60E: -0.89%) owing to its larger overall diameter (13.0mm vs 12.5mm).
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.