JCRS HIGHLIGHTS

OCT AND ACCOMMODATION

The mechanisms of accommodation and presbyopia are not yet fully understood. Swept-source anterior segment optical coherence tomography (AS-OCT) could help by providing high resolution real-time measurement of the accommodation process, report Italian researchers. They analysed 14 eyes of 14 patients aged 18 to 46 years. AS-OCT revealed that during accommodation the decrease in the anterior chamber depth was statistically significant, as were the increase in the lens thickness and the slight movement forward of the lens central point. The central cornea thickness and anterior chamber width measurements did not change statistically significantly during accommodation. A Neri et al, JCRS, “Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography”, online, March 2015.

FIVE-YEAR FOLLOW-UP OF CORNEAL INLAYS

Corneal inlays are increasingly being used for the treatment of presbyopia. They are additive and do not require tissue to be removed, they preserve future options for presbyopic correction, some of them can be used in the setting of pseudophakia and/or combined with laser refractive surgery, and they are removable. However, as yet there are very few studies reporting results even out to two years. In what may be the longest follow-up reported for these products to date, researchers now report visual acuity results, patient satisfaction and postsurgical complications in cases followed for 60 months after monocular implantation of the ultrathin Kamra small-aperture corneal inlay (model ACI7000). The long-term results indicate stable increased uncorrected near visual acuity (UNVA) and uncorrected intermediate visual acuity (UIVA), and slightly compromised uncorrected distance visual acuity (UDVA) at three years. However, a statistically significant decrease in UNVA, UIVA and UDVA was observed between 36 months and 60 months. AK Dexl et al, JCRS, “Long-term outcomes after monocular corneal inlay implantation for the surgical compensation of presbyopia”, online, March 2015.

MEASURING ACCOMMODATION USING UBM CONCLUSIONS

Ultrasound biomicroscopy (UBM) could also prove useful in evaluating the mechanisms of accommodation and presbyopia. US researchers evaluated anterior segment biometric changes in response to 0D to 6D accommodative stimuli in 1D steps in 26 patients. UBM-measured accommodative anterior segment biometry parameters had smaller variance and good repeatability. Radius of curvature of intraocular structures calculated from UBM images required distortion correction. The researchers believe this study has demonstrated the utility of automated image analysis to perform objective measurement of the accommodative biometric changes from UBM image sequences. V Ramasubramanian et al, JCRS, “Objective Measurement of Accommodative Biometric Changes Using Ultrasound Biomicroscopy”, online, March 2015.