JCRS Highlights

Vol: 45 Issue: 7 month: July 2019

Thomas Kohnen

Posted: Sunday, September 1, 2019

Cataract surgery is cost-effective and is becoming even more so, a large insurance study suggests. US researchers looked at data from public and private health insurance records. They performed cost-utility analysis with Value-Based Medicine standardisation of input and output variables. The overall analyses indicated that cataract surgery is highly cost-effective, whether for first-eye surgery, second-eye surgery or bilateral surgery. Interestingly, both the perceived value to patients and cost-efficacy showed significant increases between 2012 and 2018. For example, the cost-utility ratio of $1,001/quality-adjusted life years for first-eye surgery was 41.8% more cost-effective than in 2012 and 73.7% more cost-effective than in the year 2000.
GC Brown et al., “Cost-utility analysis of cataract surgery in the United States for the year 2018”, Vol.45, Issue 7, 927-938.

Researchers conducted a prospective study to compare pupillometry characteristics before and after implantation of the older model V4 ICL and the newer V4c lens (Staar). The Visian V4c ICL includes a 360μm central hole to allow aqueous humour to flow without the requirement for an iridotomy. The study followed 50 patients who received ICLs for three months after the surgery. ICL implantation had a miotic effect under certain illumination conditions, resulting in decreases in pupil contraction amplitude and velocity in light reflexes. Regarding the pupil light reflex, contraction amplitude and velocity declined after surgery, whereas other dynamic parameters remained unchanged. The static and dynamic pupillary characteristics were similar between the V4 and V4c ICL groups. These investigators concluded that the central hole and aqueous humour hydrodynamic difference had little influence on iris motility.
Y Zhu, “Static and dynamic pupillary characteristics in high myopic eyes with two implantable collamer lenses”, Vol.45, Issue 7, 946-951.

Angle κ, defined as the angle between the visual axis and the pupillary axis, is generally larger in hyperopic patients, and is considered as a drawback when planning excimer laser vision correction. A retrospective multi-centre study of 170 hyperopic eyes of 112 patients looked at the prevalence of preoperative, intraoperative and postoperative angle κ in hyperopic eyes and its effect on the refractive outcomes. The study found statistically significant differences between the preoperative and real-time intraoperative angle κ in eyes with a preoperative angle κ of 0.25mm or more. The preoperative magnitude of angle κ did not predict the safety, efficacy or predictability of hyperopic excimer laser vision correction. The study notes that using the preoperative larger angle κ as an intraoperative offset might cause a too nasally centred ablation zone.
A Frings et al. “Analysis of excimer laser treatment outcomes and corresponding angle κ in hyperopic astigmatism”, Vol.45, Issue 7, 952-958.