Poster winners address unexplored areas in cataract and refractive surgery

This year’s ESCRS Poster Prize winners addressed two largely unexplored areas of cataract and refractive surgery - namely, the utility of capsular tension rings (CTRs) with toric intraocular lenses (IOLs), and the occurrence of an opaque bubble layer during small incision lenticule extraction (SMILE) procedures. CATARACT CATEGORY First prize in the cataract category went to Daniel Schartmüller, Austria, for his poster titled ‘Impact of a capsular tension ring on the rotational stability of a single-piece hydrophilic acrylic intraocular lens’. In his presentation, Dr Schartmüller notes that CTRs are commonly used in eyes with weak zonules in order to stabilise the capsular bag and prevent anterior capsule phimosis. However, their ability to prevent the rotation of toric IOLs, as some have proposed, had been inadequately researched. Therefore, he and his associates conducted a study in which they recorded the rotational stability of 100 eyes that received a CTR (CTR 13/11, Human Optics, Germany) and an hydrophilic acrylic IOL, and 100 eyes implanted with the same IOL alone. They found that the CTR did appear to reduce rotation during the first hour, but soon after, the mean amount of IOL rotation increased to the point that by six months there was no significant difference between the eyes with the CTR and those without them. That is, IOLs with CTRs rotated by a mean of 4.9 degrees with a range of 0 to 28.3 degrees, and the IOLs without the rings rotated a mean of 3.7 degrees with a range of 0.4 to 50.3 degrees. Dr Schartmüller notes that, in contrast with IOLs with a CTR, IOLs implanted without it appeared to become more stable during follow-up. The results therefore make the use of the devices to improve rotational stability highly questionable, he adds. REFRACTIVE CATEGORY First prize in the refractive category went to Gisung Son, South Korea, for ‘Opaque bubble layer in small incision lenticule extraction’. In a retrospective analysis of medical records and video records of operations, the poster examined the risk factors for the opaque bubble layer (OBL) phenomenon, and its possible influence on clinical outcomes in patients who undergo the SMILE procedure. Their study included 208 consecutive eyes of 106 patients who underwent SMILE and had three months of follow-up. In each eye, Dr Son and colleagues measured the amount of OBL directly after cutting the lenticule-based pixel counts of the opaque areas obtained from surgical videos, using dedicated software. All patients had at least three months of follow-up. They found that, in 96 eyes (46.15%), the OBL opacified more than 5% of the total corneal area. Those eyes had significantly higher mean corneal thickness than those with less than 5% of corneal opacification (570.25um vs 555.84; p=0.002). They also a shallower ablation depth (87.50um vs 101.69um; p<0.001). In addition, surgical time was significantly longer in those with more than 5% of corneal opacification (421.67 seconds) than in those with less than that amount (290.56 seconds; p<0.001). The efficacy and the safety were statistically equivalent. However, whereas all of those eyes with less than 5% of OBL corneal opacification were within 0.5D of target refraction, 6.5% of those with larger amounts of opacification were more than 0.5D off target.