Vol 43: Issue: 12 Month: December 2017
COMPARING LASIK APPROACHES FOR MYOPIC ASTIGMATISM
A retrospective study of 128 patients compared vector planning with manifest refraction planning for the treatment of myopic astigmatism. At a six-month follow-up, researchers observed no significant differences between the two groups in terms of difference between corrected distance visual acuity and uncorrected distance visual acuity (UDVA) and postoperative UDVA. Significant differences were observed between the two groups in terms of achieved spherical equivalent, corneal toricity and ocular residual astigmatism. Vector planning helps in retaining the natural corneal shape after refractive surgery without inducing manifest refractive astigmatism.
MC Arbelaez et al., JCRS, “Clinical outcomes of laser in situ keratomileusis with an aberration-neutral profile centred on the corneal vertex comparing vector planning with manifest refraction planning for the treatment of myopic astigmatism”, Volume 43, Issue 12, 1504–1514.
FEMTOSECOND INCISIONS FOR CATARACT SURGERY
Researchers reviewed surgical videos to compare the expected versus actual position and dimension of corneal incisions during femtosecond laser-assisted cataract surgery. The primary incision internal and external exits were within 142μm ± 70 and 151 ± 75μm of the planned position. The dimensions and position did not correlate with biometric variables. However, the superior secondary incision external exit was displaced centrally (321 ± 84μm) and the internal exit was displaced peripherally (84 ± 102μm). The inferior secondary incision external exit was displaced centrally (278 ± 142μm) and the internal exit was displaced peripherally. Eye tilt and eccentric docking influenced the position of the secondary incisions.
C Baal et al., JCRS, “Factors affecting corneal incision position during femtosecond laser–assisted cataract surgery”, Volume 43, Issue 12, 1541–1548.
BEST WAY TO MEASURE LENS DENSITY?
A prospective case series of 110 eyes (51 with cataract and 59 controls) assessed a new objective cataract grading method based on lens densitometry on swept-source optical coherence tomography (SS-OCT) scans provided by the IOLMaster 700. This proved to be a reliable technique to grade cataract severity. In eyes with an average lens density greater than 82.9 pixel units, surgery might be discussed if a patient has visual impairment. The average lens density strongly correlated with previously validated objective methods such as objective scatter index and nuclear staging measurements. An automated measurement of the average lens density on SS-OCT scans provided by the IOL measuring device would allow for assessing cataract severity to help surgeons to make surgical decisions in controversial cases.
C Panthier et al., JCRS, “New objective lens density quantification method using swept-source optical coherence tomography technology: Comparison with existing methods”, Volume 43, Issue 12, 1575–1581.