JCRS HIGHLIGHTS

[caption id='attachment_2788' align='alignright' width='271' caption='Thomas Kohnen, Associate Editor of JCRS'][/caption]

Subclinical macular oedema post-cataract

Subclinical macular oedema after uneventful phacoemulsification is a poorly understood issue of growing concern. A new optical coherence tomography (OCT) study indicates post-oedema is associated with changes in the outer nuclear layer of the retina, comprising the photoreceptors. Moreover, it appears that the incidence of the problem may be lower when using a femtosecond laser-assisted surgical approach. Researchers evaluated and compared thickness changes in the retinal layers in the macula with OCT segmentation software after femtosecond laser-assisted phacoemulsification and conventional phacoemulsification in a small study comprising 25 eyes of 25 patients. There was no significant difference between the two groups in terms of age, sex, refractive errors, phaco time or axial length. The study revealed statistically significant differences in absolute outer nuclear layer thickness and relative outer nuclear layer thickness in the inner and outer macular rings between the two groups. After adjusting for effective phaco time in multivariate modelling, type of surgery showed a significantly lower relative outer nuclear layer ratio in the inner retinal ring and in the outer retinal ring. After femtosecond laser-assisted cataract extraction, subclinical macular thickening, which was most prominent four to eight weeks after surgery, was delayed and less than with the standard ultrasound technique. The researchers note that femtosecond laser-assisted cataract surgery may provide an option for less traumatic cataract extraction, and could prove especially important in the treatment of patients with diabetes and diabetic retinopathy or even in patients with uveitis. 

• Z Nagy et al., JCRS, 'Macular morphology assessed by optical coherence tomography image segmentation after femtosecond laserassisted and standard cataract surgery', Volume 38, Issue 6, 941-946 

Multifocal IOL vs. single optic accommodating IOL

Spanish investigators compared visual outcomes and intraocular optical quality in patients receiving a new low-addition power multifocal refractive IOL with rotational asymmetry (Lentis-Mplus LS-312 MF15) and a single-optic accommodating IOL (Crystalens HD). The study included 66 eyes in 40 patients. Postoperatively, both groups had a significant improvement in the uncorrected and corrected distance visual acuities and uncorrected and corrected near visual acuities. Distance-corrected near visual acuity was significantly better in the multifocal group postoperatively. No significant differences in UNVA and CNVA were detected postoperatively. In the defocus curve, the multifocal group had significantly better visual acuities at several defocus levels. The accommodating group had better contrast sensitivity under photopic conditions at all spatial frequencies. The multifocal group had significantly higher postoperative intraocular tilt. The researchers conclude that while both IOLs restored distance vision, the refractive multifocal IOL provided better near visual rehabilitation.

• n J Alió et al., JCRS, 'Visual outcomes with a single-optic accommodating intraocular lens and a low-addition-power rotational asymmetric multifocal intraocular lens', Volume 38, Issue 6, 978-985. 

Refractive laser in thin corneas

Many surgeons consider a preoperative central corneal thickness greater than 500 μm to be the cut-off value for laser refractive surgery, although some have achieved good results in eyes with a cornea thinner than 500 μm. A new study reviewed the medical records of nearly 200,000 cases, comparing longterm refractive and visual outcomes of LASIK and laser surface ablation in eyes with corneas thinner than 470 μm. The final study sample comprised 128 eyes of 84 patients (LASIK, 40 eyes; LASEK, 84 eyes; PRK, 4 eyes). Both techniques were effective, safe and predictable in eyes with corneas thinner than 470 μm, normal preoperative topography, and a residual corneal bed thickness greater than 250 μm.

• M Reza et al, JCRS, 'Long-term comparison of laser in situ keratomileusis versus laser surface ablation in corneas thinner than 470 μm', Volume 38, Issue 6, 1034-1042.