Dislocation Force Of Intrascleral Flange-Fixated Iol Haptics

Published 2023 - 41st Congress of the ESCRS

Reference: PP04.03 | DOI: 10.82333/whwe-bt10

Authors: Spela Stunf Pukl* ¹ , Martin Kronschlaeger ² , Manuel Ruiss ² , Stéphane Blouin ³ , Rustu Emre Akcan ² , Oliver Findl ²

¹University Eye Hospital UKC,Ljubljana,Slovenia;Vienna Institute for Research in Ocular Surgery (VIROS), A Karl Landsteiner Institute,Vienna,Austria, ²Vienna Institute for Research in Ocular Surgery (VIROS), A Karl Landsteiner Institute,Vienna,Austria, ³Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of ÖGK and AUVA Trauma Centre Meidling,Vienna,Austria

To measure the dislocation forces in relation to the haptic material, the flange size and the needle used for intrascleral flnged fixated IOL.

Vienna Institute for Research in Ocular Surgery (VIROS), A Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria

Either a 30 gauge (G) thin-wall or a 27 G standard needle was used for formation of a 2 mm tangential scleral tunnel. Different IOLs with PVDF and PMMA haptics were used for laboratory imitaion of intrascleral IOL flange-fixation. Flanges were created by heating 1 mm of the haptics, non-forceps assisted in PVDF and forceps assisted in PMMA haptics. Dislocation force was measured in non-preserved cadaver sclera using a tensiometer device. Dislocated flanges were microscopically analysed.

The dislocation force for the 30 G thin-wall needle tunnels and the PVDF haptic flanges was 1.582 ± 0.675 N (n = 10), whereas for the PMMA haptic flanges it was significantly smaller (0.697 ± 0.14 N, n = 9, p = 0.003).

When a standard 27 G needle was used for the tunnel formation, the dislocation force was 1.1 N for the PVDF haptic flanges, but 0 N for the PMMA haptic flanges.

The PVDF flanges were of mushroom like shape and the PMMA flanges were of conic like shape. The flange size positively correlated to the dislocation force in the experiments with the 30 G thin-wall needle tunnels for flanges bigger than 384 micrometres.

Imitating the Yamane intrascleral flange-fixation technique, the experimental study proved highest dislocation forces for the PVDF haptic flanges with characteristic mushroom like shape, 30 G thin-wall needle scleral tunnels, and bigger flange size. Forceps assisted flange formation in the PMMA haptics did not compensate the disadvantage of the PMMA haptics' characteristic conic shaped flange.