JCRS Highlights selected by Professor Thomas Kohnen

Volume 44, Issue 2, February 2018

Thomas Kohnen

Posted: Friday, June 1, 2018

Femtosecond laser-assisted cataract surgery (FLACS) can be applied successfully in eyes with cataract and a foldable anterior or posterior chamber pIOL in situ, a new study suggests. Investigators report their experience with five eyes in which a femtosecond laser was used to create a capsulotomy, perform lens fragmentation and create corneal incisions with the pIOL in situ. Two eyes had an anterior chamber phakic IOL in place while three had posterior chamber phakic IOLs. The capsulotomy was successful in all cases. Lens fragmentation was complete in four eyes and incomplete in one eye, where trapped cavitation bubbles in the space between the posterior chamber pIOL and anterior lens capsule were evident as a result of a shallow vault of the pIOL. Potential advantages of the FLACS approach include less endothelial cell reduction and higher capsulotomy circularity compared with conventional manual cataract surgery. T Kohnen et al., JCRS, “Femtosecond laser-assisted cataract surgery in eyes with foldable anterior or posterior chamber phakic intraocular lenses”, Vol. 44, Issue 2, 124–128.

Meibomian gland dysfunction is high in patients presenting for cataract surgery, report researchers who conducted a prospective study of 342 eyes of 180 patients. Patients underwent comprehensive preoperative evaluation of lipid layer thickness, partial blink rate measurements and gland structure. They also completed the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire. Fifty-two percent of patients had meibomian gland dysfunction and 56% had meibomian gland atrophy equal to or more than Arita grade 1. Meibomian gland function correlated significantly with lipid layer thickness, symptoms, age and gland atrophy. Fifty percent of patients with meibomian gland dysfunction were asymptomatic. This underscores the importance of preoperative meibomian function and structure assessment, the authors note. B Cochener et al., JCRS, “Prevalence of meibomian gland dysfunction at the time of cataract surgery”, Vol. 44, Issue 2, 144–148.

A new algorithm that incorporates the effect of posterior corneal astigmatism appears to reduce the astigmatic prediction error after toric IOL implantation significantly. The algorithm was evaluated in a study of 274 eyes. The investigators report that this algorithm significantly reduced the centroid error in predicted refractive astigmatism. Moreover, the centroid error reduced from 0.50 @ 1 to 0.19 @ 3 when using preoperative K values and from 0.30 @ 0 to 0.02 @ 84 when using postoperative K values. Patients who had anterior corneal against-the-rule, with-the-rule and oblique astigmatism had improvement with the algorithm. In addition, the algorithm reduced the median absolute error in all groups (P < .001). C Canovas et al., JCRS, “New algorithm for toric intraocular lens power calculation considering the posterior corneal astigmatism”, Vol. 44, Issue 2, 168-174.