Hydrophilic vs hydrophobic: which is the better option?
Measuring IOL success in broader terms
"Hydrophilic IOLs tend to be easier for the surgeon to implant, and are therefore, particularly in the case of very small incisions, probably a more suitable surgical option than hydrophobic IOLs," said Christophe Chassain, MD, an anterior segment surgeon at the Clinique Beau-Soleil, Montpellier, France. "Postoperatively, though, hydrophilic lenses have a worse reputation for prevention of posterior capsule opacification (PCO), which traditionally has been a prime metric used to determine the success of IOL implantation."
PCO: investigating hydrophilic IOLs
To investigate the truth of this assumption, Dr Chassain conducted a two-year retrospective study to establish the rate of posterior capsule YAG procedures following implantation of the SlimFlex IOL (PhysIOL).
The SlimFlex is a 26% hydrophilic monobloc IOL with a 6 mm optic, and a 360° posterior square edge. It has an overall diameter of 10.5 mm, with four haptics at a 5° angle. The lens can be injected through a 2.4 mm incision. MicroSLIM — the microincision version of the lens, which can be injected through a 1.8 mm incision — is made from 25% hydrophilic material.
Dr Chassain implanted 344 SlimFlex lenses into 191 female and 153 male subjects with a mean age of 77 years (range: 46–94 years) and a mean dioptric power of +20.5 D (range: 9–28 D). Topical anaesthesia was used and, during the coaxial surgery, the posterior capsule was cleaned; FlexiRing intracapsular rings (IOLTECH Laboratories) were implanted into 34 eyes. A rhexis of 5.5 mm was achieved in 66% of cases; the rhexis IN position was 76% with an optic overlap.
Similar PCO rates with both lens types
"Of the 344 subjects implanted with the SlimFlex lens, 3.2% required further treatment with Nd:YAG posterior capsulotomy to combat PCO. Of these, four YAGs were performed in the 180 eyes with an IN rhexis; six in the 57 eyes with an IN/OUT rhexis; one in the four eyes with posterior fibrosis, and two in the 34 eyes implanted with a FlexiRing," reported Dr Chassain.
The mean follow-up period was 20.6 months (range: 11–28 months). At this stage, 68.6% of subjects had achieved a clear central posterior capsule.