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PURPOSE: To report the 5-year occurrence, management, and outcomes of 12 eyes diagnosed as having central toxic keratopathy (CTK) after femtosecond laser–assisted in situ keratomileusis (FS-LASIK). METHODS: A retrospective chart review was conducted on 20,622 FS-LASIK procedures performed at a single site from January 2015 to December 2019 to identify patients diagnosed as having central toxic keratopathy. Preoperative and postoperative visual acuity, refraction, and imaging were recorded and analyzed. RESULTS: CTK occurred in 12 eyes of 8 patients after FSLASIK. A total of 75% of eyes were diagnosed during an outbreak that happened over 2 months and the remaining 25% were considered sporadic. Five eyes were treated with flap lift and irrigation and 7 eyes were treated non-surgically. The average time to resolution of CTK in eyes that underwent flap lift and irrigation was 53 days compared to 33 days in eyes treated non-surgically. All 5 eyes treated with flap lift and irrigation ultimately achieved uncorrected distance visual acuity of 0.1 logMAR or better, whereas only 3 of 7 eyes treated non-surgically achieved the same. At the final postoperative visit, the eyes treated with flap lift and irrigation measured on average 14 µm thinner and 1.60 diopters (D) flatter than the expected postoperative pachymetry and keratometry, respectively. Those treated non-surgically were on average 28 µm thinner and 1.70 D flatter than expected. CONCLUSIONS: CTK is a rare complication of FS-LASIK but can occur in clusters. Although management of CTK is debated, flap lift and irrigation may lead to better visual acuity and refractive and anatomic outcomes in some cases. [ J Refract Surg . 2021;37(1):25–31.]

Majid Moshirfar,1– 3 Andrew C Thomson,4 William B West Jr,5 MacGregor N Hall,4 Shannon E McCabe,1 Robert J Thomson,4 Yasmyne C Ronquillo,1 Phillip C Hoopes1 1Hoopes Vision Research Center, Hoopes Vision, Draper, UT, USA; 2John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA; 3Utah Lions Eye Bank, Murray, UT, USA; 4McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, USA; 5University of Utah School of Medicine, Salt Lake City, UT, USACorrespondence: Majid MoshirfarHoopes Vision Research Center, 11820 S. State Street Suite #200, Draper, UT 84020, USATel +1 801-568-0200Fax +1 801-563-0200Email cornea2020@me.comPurpose: To assess a single site’s initial experience with SMILE for the treatment of myopic astigmatism and compare outcomes and vector analysis results with the US Food and Drug Administration (FDA) results and published literature.Patients and Methods: Forty-eight eyes (29 patients) with mean preoperative sphere of − 5.11 ± 1.31 diopters (D) and cylinder of − 1.12 ± 0.60 D underwent SMILE. Visual acuity, refractive, and vector analysis outcomes as well as subjective measures were reported at three and twelve months postoperatively and compared with FDA results and the published literature between 2014 and 2020 involving treatment of patients with mean cylinders of >− 0.50 to ≤− 3.00 D.Results: At three and twelve months, 43 and 32 eyes were evaluated, respectively. At twelve months, mean cylinder power was reduced to − 0.38 ± 0.38 D with 78.1% achieving ≤± 0.50 D. Uncorrected distance visual acuity (UDVA) ≥ 20/20 was achieved in 77.4% of eyes by twelve months with 100% achieving ≥ 20/30 UDVA. No loss of corrected distance visual acuity was observed in eyes seen at twelve months. Correction index (CI) at twelve months was 0.90 indicating overall undercorrection of 10%. Twelve-month CI was 0.96, 0.90, and 0.83 in eyes with preoperative cylinders of

Femtosecond (FS) lasers initially had a higher incidence of diffuse lamellar keratitis (DLK) compared with microkeratome flap creation. It has been theorized that higher-frequency lower-energy (HFLE) FS lasers would reduce the incidence of DLK. Our study sought to evaluate the incidence of newer HFLE FS lasers with pulse frequencies above 60 kHz. It was a retrospective case-control study evaluating the incidence of DLK following flap creation with one of three FS lasers (AMO iFs, WaveLight FS200, Zeiss VisuMax). Uncomplicated LASIK cases were included as the control group (14,348 eyes) and cases of DLK were recorded in the study group (637 eyes). Of the 637 cases of DLK, 76 developed stage II, 25 progressed to stage III, and only three developed stage IV DLK. The overall incidence rate of DLK was 4.3%, it has fallen with the invention of newer HFLE FS lasers and is approaching the DLK incidence rates of DLK with microkeratome.

Terrestrial organisms such as shoreline spiders that consume prey from aquatic food webs can be contaminated with methylmercury (MeHg). However, no studies have examined the relationship between MeHg contamination of shoreline spider taxa and the proportion of aquatic and terrestrial prey in their diets. The present study had 2 objectives: 1) determine concentrations of MeHg in 7 taxa of shoreline spiders, and 2) assess the relationship between concentrations of MeHg in spiders and the proportion of aquatic and terrestrial prey in spider diets. We collected shoreline spiders, emergent aquatic insects, and terrestrial insects from in and around 10 experimental ponds. Methylmercury concentrations were greatest in spiders, intermediate in aquatic insects, and lowest in terrestrial insects. The elevated MeHg concentrations in spiders indicate that they were feeding, at least in part, on emergent aquatic insects. However, variability in MeHg concentration observed among spider taxa suggested that the proportion of aquatic and terrestrial prey in spider diets likely varied among taxa. We estimated the proportion of aquatic and terrestrial prey in the diet of each spider taxon from the nitrogen (δ15 N) and carbon (δ13 C) isotope values of spiders and their potential aquatic and terrestrial prey items. The median proportion of aquatic prey in spider diets varied by almost 2-fold, and MeHg concentrations in shoreline spiders were strongly correlated with the proportion of aquatic prey in their diet. In the present study, we demonstrate for the first time that the degree of connectivity to aquatic food webs determines MeHg contamination of shoreline spiders. Environ Toxicol Chem 2019;38:2503-2508. © 2019 SETAC.

Methylmercury (MeHg) is an aquatic contaminant that can be transferred to terrestrial predators by emergent aquatic insects. We assessed the effects of month and pond permanence on dipteran-mediated MeHg flux (calculated as emergent dipteran biomass × dipteran MeHg concentration) in 10 experimental ponds. Emergent dipterans were collected weekly from permanent ponds with bluegill (Lepomis macrochirus; n = 5) and semipermanent ponds without fish (n = 5) over a 7-mo period (February-August, 2015). We detected a significant effect of month on MeHg flux from 6 dipteran taxa and aggregate MeHg flux, with the highest MeHg flux from herbivorous/detritivorous chironomid midges and predatory midges in March; biting midges, phantom midges and herbivorous/detritivorous orthoclad midges in April; and mosquitoes in August. Aggregate dipteran-mediated MeHg flux peaked in April and then declined throughout the remainder of the summer. We did not detect a significant main effect of pond permanence or a significant month × pond permanence interaction effect on MeHg flux for any of the taxa examined in the present study or for aggregate MeHg flux. Given their ubiquity in aquatic systems and their importance in food webs at the land-water interface, dipterans are important taxa that should not be overlooked as a part of the Hg cycle. Environ Toxicol Chem 2018;37:1846-1851. © 2018 SETAC.