August 2019


Journal of Cataract & Refractive Surgery

In the journal: August 2019

Phacoemulsification with the big bubble DALK technique: a variant of the triple procedure

Roberto Pinto Coelho, MD, André Messias, MD
When patients have ectasia and cataracts together, this can create surgical hurdles. In most cases, surgeons take a two-step approach, first performing the corneal graft, then coming back to undertake cataract surgery. Sometimes a triple procedure in which the cataract surgery complete with intraocular lens implantation is done in conjunction with graft surgery. The visual disability period with this approach is shorter than for the two-step technique, and costs are lower for the patient. In some cases a triple procedure involving the big bubble DALK technique followed by phacoemulsification is performed. However, rupture of Descemet’s membrane is the danger here, requiring extreme caution. Investigators instead performed the triple procedure with phacoemulsification first then employed the big bubble DALK technique for placing a corneal graft.

Decentration measurements using the tangential curvature topography and Scheimpflug tomography pachymetry difference maps after small-incision lenticule extraction procedure

Byunghoon Chung, MD, Hun Lee, MD, Cynthia Roberts, PhD, David Sung Yong Kang, MD, Dan Reinstein, MD, Seung Ki Jean, MR, Eung Kweon Kim, MD, PhD, Kyoung Yul Seo, MD, Tae-im Kim, MD
In this retrospective case series involving 155 eyes, investigators considered what happened after the small-incision lenticule extraction (SMILE) procedure to the agreement between tangential curvature topography generated by a Keratron Scout (Optikon) and pachymetry difference maps made for each eye via the Pentacam system (Oculus). Investigators found that with the tangential curvature difference maps, there was a 0.27 mm magnitude of decentration versus a 0.26 mm magnitude with the pachymetry difference maps, which was not significantly different. The vector difference in pupillary offset between pre- and postoperative measurements from the pachymetry difference map significantly correlated with the magnitude of vector differences of decentration between the two maps. The vector difference plot showed a wide distribution spread to all four quadrants, demonstrating a lack of agreement. Investigators concluded that while there was no significant difference between the scalar magnitude of decentration with the tangential topography difference maps and pachymetry difference maps, the vector differences were apparent, with increasing pupillary offset resulting in increasing error present in the pachymetry maps, indicating a lack of agreement.

Optical behavior of the eye implanted with extreme intraocular lens powers

Renan Oliveira, MD, Liberdade Salerno, MD, Michael Mimouni, MD, Ana Belén Plaza-Puche, MSc, Jorge Alió, MD
The aim in this prospective comparative study was to examine how very low- and high-powered spherical monofocal lenses placed after cataract surgery impacted ocular aberrations from the surgery. In the study, 88 eyes in which a spherical monofocal IOL was implanted following cataract surgery were put in 1 of 3 groups based on the power of their IOL. Group 1 included lenses ranging from +20 D to +23 D, while group 2 included those with less than +10 D of power. Those in group 3 had lenses with +29 D of power or more. At the 3-month mark investigators found that in terms of refractive error, corneal aberrometry, or total ocular higher-order aberrations, there were no differences among the groups at any of the pupil diameters considered. When it came to spherical aberration, they likewise found that with a 4-mm pupil there was no significant differences among the groups. However, with either a 4.5-mm or 5.0-mm pupil, group 2 had significantly lower spherical aberration compared to group 1 or group 3. When group 1 and 3 were compared, spherical aberration was not significantly different no matter the pupil diameter. Contrast sensitivity was not lowered as a result of higher spherical aberration. The conclusion reached was that high-powered positive IOLs only induce a negligible, clinically insignificant amount of aberrations, despite theoretical evidence to the contrary.

In the journal: August 2019 In the journal: August 2019
Ophthalmology News - EyeWorld Magazine
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