September 2020


Journal of Cataract & Refractive Surgery
In the journal: September 2020

Propensity and quantification of aerosol and droplet creation during phacoemulsification with high-speed shadowgraphy amid COVID-19 pandemic

Jeremy Kieval, MD, Saba Al-Hashimi, MD, Richard Davidson, MD, D. Rex Hamilton, MD, Mitchell Jackson, MD, Scott LaBorwit, MD, Larry Patterson, MD, Karl Stonecipher, MD, and Kendall Donaldson, MD, for the ASCRS Refractive Cataract Surgery Subcommittee
In a laboratory study, researchers observed and quantified aerosols and droplets generated during phacoemulsification to better understand the possibility of cataract surgery spreading COVID-19. The study was performed on enucleated goat eyes and cadaveric corneo-scleral rims mounted on an artificial anterior chamber. Standard sculpt and quadrant removal settings were used with 2.2- and 2.8-mm tips. High-speed shadowgraphy was used to show droplets and aerosols that might form, the size of which were quantified as a mean outcome measure. The research found no aerosol generation in closed chamber, longitudinal phacoemulsification using a peristaltic pump with a straight tip. When the wound was larger, there was a leak at the main wound, with atomization observed “only when the phaco tip was completely exposed next to the ocular surface.” This resulted in a droplet that was about 50 µm, which had an estimated maximum spread of 1.3 m. The authors concluded that with no aerosol generation during microincision/standard phaco, cataract surgery is safe to perform during the COVID-19 era when adequate precautions are taken to protect against other modes of transmission.

The best optical zone for small incision lenticule extraction in high myopic patients

Jia-Hao Zhang, MD, Shu-Rong Wang, MD, Yu-Xi He, MD, Bo-Yuan Yao, MD, Yan Zhang, MD
Given the current parameters for small incision lenticule extraction (SMILE), such as cap thickness, refractive correction, residual stromal bed thickness, and optical zone diameter, highly myopic patients are less likely to be offered the procedure. This study noted that the programmed optical zone (POZ) for SMILE is adjusted between 5.0 and 8.0 mm, with 6–7 commonly used in clinical practice. A larger optical zone, the study authors wrote, can provide better visual quality and fewer higher order aberrations. But a literature review identified several parameter designs for highly myopic patients that could be advantageous, including a 6.2 mm POZ for those with more than –7.5 D of myopia. A 6.1–6.4 mm POZ compared to 6.5–6.8 mm had slightly worse night vision, but total visual quality was not significantly decreased. The authors also noted that corneal cap thickness had “limited impact on long-term visual prognosis and corneal biomechanics after adjustment of corrected spherical equivalent power according to the corneal cap thickness.”

Comparison of clinical outcomes of three trifocal intraocular lenses

Filomena Ribeiro, MD, Tiago Ferreira, MD
Clinical outcomes of three trifocal lenses—FineVision POD F (PhysIOL), RayOne Trifocal (Rayner), and AcrySof IQ PanOptix (Alcon)—were included in this prospective, randomized, comparative study. There were 15 patients in each group who received bilateral implantation of their assigned lens (90 eyes total) with visual acuity, refraction, defocus curve, contrast sensitivity, and subjective quality of vision assessed 3 months postop. There was no significant difference among the groups at distance, intermediate, and near visual acuity or in postop refraction. Binocular uncorrected intermediate visual acuity of 0.10 logMAR or better was observed in 93.33% of patients in each group, while uncorrected near of 0.10 logMAR or better was 86.67%, 93.33%, and 86.67% in the FineVision, RayOne, and PanOptix groups, respectively. Overall, there was no statistically significant differences in contrast sensitivity or quality of vision scores, though the authors did find that the RayOne group had less depth perception severity than the FineVision group.

In the journal: September 2020 In the journal: September 2020
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