Background:

Chorioretinal adhesion strength is an important factor in determining the outcome of rhegmatogenous retinal detachment surgery. The precise quantification of the strength of chorioretinal compound and its nature in experiments carried out a number of authors to mesure the force required to detach the retina from the choroid. The results indicate that regardless of the method of exposure (cryo, diathermy, or laser coagulation), forming lasting chorioretinal connections going on for 2-3 weeks.

Purpose:

To evaluate high frequency electric welding (HFEW) as a novel technique for retinopexy with improved immediate chorioretinal adhesion.

Methods:

In a prospective, randomized, experimental study, we examined 104 eyes of 52 rabbits randomly assigned to either standard 810 nm endolaser retinopexy, 14-16V or 18-20V HFEW retinopexy. A full thickness fragment of eye wall tissue containing the retinopexy was isolated 1 hour, 3 days, 1 week or 1 month after the intervention, respectively, and fixed to an analytical electronic scale. A nylon suture passed through the retina was vertically lifted by the advancement lever of a custom-made motor controlled biomechanical force elongation tester. The reduction in weight at the time of retinopexy rupture was registered as a measure for retinopexy adhesion strength.

Results:

One-hour post exposure, adhesive strengths were significantly higher in the 14-16V HFEW group than in the control group (212 ± 26.6mg vs. 104 ± 10mg, p=0.0001). 18-20V HFEW yielded 122±16mg (p=0.024) while laser retinopexy did not significantly increase adhesive strength 114±14.0mg (p=0,149). Adhesive strengths were significantly increased later throughout follow-up for all retinopexy techniques: Three days post-OP 14-16V HFEW 224 ± 30.0mg (p=0,0001), 18-20V HFEW 128 ±15.6(p=0,001), laser 131 ± 12.7mg (p=0,0007); at one week 14-16 HFEW 235 ± 24.7mg, 18-20V HFEW 213 ± 22.4mg, laser 188 ± 18.7mg (p≤0,0001 in all experimental groups); one month post-OP 14-16V HFEW 275 ± 32.0mg, 18-20V HFEW 283 ± 31.0mg, laser 276 ± 21.7mg, respectively (p≤0,0001 in all experimental groups). Conclusion: HFEW represents a novel technique for retinopexy during vitreoretinal surgery. Its main advantage is a firm chorioretinal adhesion immediately after expo sure. In non-vitrectomized eyes, welding at 14-16V generates highest immediate adhesion strengths.