1
|
de Andrade Ramos L, Seullner Brandão CV, Arce CG, Micheline L, Gordon Gandolfi M, Padovani C. Simulated keratometry and central corneal thickness measured in cats by autokeratometer, ultrasonic pachymeter, and Galilei G6™. Vet Ophthalmol 2022; 26:128-134. [PMID: 36383444 DOI: 10.1111/vop.13039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The aims of this study were to compare the central corneal thickness (CCT) measured by an ultrasonic pachymeter (SP-100, Tomey, Japão) versus the Galilei G6™ (Ziemer Ophthalmics System AG, Port, Switzerland) and to compare the simulated keratometry (SimK) measured by an autokeratometer (KM 500 Nidek) versus the Galilei G6™. ANIMAL STUDIED Eighteen mixed-breed cats, 10 males, and eight females, aged between 18 and 48 months, were evaluated (n = 36 eyes). PROCEDURE(S) The cats were manually restrained using a blanket. The operator held the autokeratometer close to the eye and measured the SimK. Next, one anesthetic eye drop was applied; the operator lightly touched the corneal using the ultrasound pachymeter and measured the CCT. At another moment, the cats were sedated using meperidine and xylazine and then evaluated using the Galilei. Student's t-test was employed to perform the statistical analyzes. RESULTS Considering the CCT, the ultrasound pachymeter provided mean ± SD of 623.03 ± 48.17 μm and the Galilei 617.34 ± 53.38 μm. The autokeratometer produced a SimK of 38.20 ± 0.84D (8.84 ± 0.20 mm) and the Galilei 38.37 ± 0.83D (8.80 ± 0.19 mm). The CCT and SimK did not differ statistically regardless of the device used. CONCLUSION To the best of the authors' knowledge, this is the first work to compare the CCT measured by the Galilei versus the ultrasonic pachymeter and to compare the SimK measured by the Galilei versus the keratometer in cats. No statistical difference was found considering the CCT and the SimK measured by the different devices.
Collapse
Affiliation(s)
- Leticia de Andrade Ramos
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science São Paulo State University ‐ UNESP São Paulo Brazil
| | - Cláudia Valéria Seullner Brandão
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science São Paulo State University ‐ UNESP São Paulo Brazil
| | - Carlos Guillermo Arce
- Contact Lens, Cornea, Refractive Surgery, Research & Technology Sectors Ophthalmologic Hospital and Eye Bank of Sorocaba São Paulo Brazil
| | - Laura Micheline
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science São Paulo State University ‐ UNESP São Paulo Brazil
| | - Micaella Gordon Gandolfi
- Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science São Paulo State University ‐ UNESP São Paulo Brazil
| | - Carlos Roberto Padovani
- Department of Biostatistics, Bioscience Institute São Paulo State University ‐ UNESP São Paulo Brazil
| |
Collapse
|
2
|
Clinical outcomes of corneal refractive surgery comparing centration on the corneal vertex with the pupil center: a meta-analysis. Int Ophthalmol 2020; 40:3555-3563. [PMID: 32671600 DOI: 10.1007/s10792-020-01506-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 07/06/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To compare the visual and refractive outcomes between centration on the corneal vertex and the pupil center in corneal refractive surgery. METHODS A comprehensive literature search was conducted using PubMed, MEDLINE, EMBASE, and the Cochrane Library to identify relevant studies. The primary outcomes were the postoperative spherical equivalent (SE), effectiveness [uncorrected distance visual acuity (UDVA) ≥ 20/20, eyes within ± 0.50 diopter (D) of target refraction], and safety [loss ≥ 2 lines of corrected distance visual acuity (CDVA)]. Higher-order aberrations were considered secondary outcomes. RESULTS Seven studies describing a total of 1964 eyes were included in this meta-analysis. A statistical significance in postoperative SE was found between the two centration methods for the correction of myopia that favor the CV-centered method (p < 0.001). No significant differences were observed in the proportion of eyes with UDVA ≥ 20/20 or loss ≥ 2 lines of CDVA postoperatively. However, the proportion of eyes within ± 0.50 D was slightly higher (p = 0.02) and the coma aberration was much lower in the corneal vertex-centered method (p < 0.001). CONCLUSION Preferable visual and refractive outcomes could be achieved with either centering on the corneal vertex or pupil center in corneal refractive surgery; however, the corneal vertex-centered method has shown partial benefits in some clinical indices. In order to obtain higher quality of clinical evidences, more randomized controlled trials (RCTs) are required in further investigations.
Collapse
|
3
|
Hastings GD, Marsack JD, Thibos LN, Applegate RA. Combining optical and neural components in physiological visual image quality metrics as functions of luminance and age. J Vis 2020; 20:20. [PMID: 32692825 PMCID: PMC7424108 DOI: 10.1167/jov.20.7.20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 03/23/2020] [Indexed: 12/02/2022] Open
Abstract
Visual image quality metrics combine comprehensive descriptions of ocular optics (from wavefront error) with a measure of the neural processing of the visual system (neural contrast sensitivity). To improve the ability of these metrics to track real-world changes in visual performance and to investigate the roles and interactions of those optical and neural components in foveal visual image quality as functions of age and target luminance, models of neural contrast sensitivity were constructed from the literature as functions of (1) retinal illuminance (Trolands, td), and (2) retinal illuminance and age. These models were then incorporated into calculation of the visual Strehl ratio (VSX). Best-corrected VSX values were determined at physiological pupil sizes over target luminances of 104 to 10-3 cd/m2 for 146 eyes spanning six decades of age. Optical and neural components of the metrics interact and contribute to visual image quality in three ways. At target luminances resulting in >900 td at physiological pupil size, neural processing is constant, and only aberrations (that change as pupil size changes with luminance) affect the metric. At low mesopic luminances below where pupil size asymptotes to maximum, optics are constant (maximum pupil), and only the neural component changes with luminance. Between these two levels, both optical and neural components of the metrics are affected by changes in target luminance. The model that accounted for both retinal illuminance and age allowed VSX, termed VSX(td,a), to best track visual acuity trends (measured at 160 and 200 cd/m2) as a function of age (20s through 70s) from the literature. Best-corrected VSX(td,a) decreased by 2.24 log units between maximum and minimum target luminances in the youngest eyes and by 2.58 log units in the oldest. The decrease due to age was more gradual at high target luminances (0.70 log units) and more pronounced as target luminance decreased (1.04 log units).
Collapse
Affiliation(s)
| | | | - Larry N. Thibos
- School of Optometry, Indiana University, Bloomington, IN, USA
| | | |
Collapse
|
4
|
Hindman HB, DeMagistris M, Callan C, McDaniel T, Bubel T, Huxlin KR. Impact of topical anti-fibrotics on corneal nerve regeneration in vivo. Exp Eye Res 2019; 181:49-60. [PMID: 30660507 PMCID: PMC6443430 DOI: 10.1016/j.exer.2019.01.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 12/12/2022]
Abstract
Recent work in vitro has shown that fibroblasts and myofibroblasts have opposing effects on neurite outgrowth by peripheral sensory neurons. Here, we tested a prediction from this work that dampening the fibrotic response in the early phases of corneal wound healing in vivo could enhance reinnervation after a large, deep corneal injury such as that induced by photorefractive keratectomy (PRK). Since topical steroids and Mitomycin C (MMC) are often used clinically for mitigating corneal inflammation and scarring after PRK, they were ideal to test this prediction. Twenty adult cats underwent bilateral, myopic PRK over a 6 mm optical zone followed by either: (1) intraoperative MMC (n = 12 eyes), (2) intraoperative prednisolone acetate (PA) followed by twice daily topical application for 14 days (n = 12 eyes), or (3) no post-operative treatment (n = 16 eyes). Anti-fibrotic effects of MMC and PA were verified optically and histologically. First, optical coherence tomography (OCT) performed pre-operatively and 2, 4 and 12 weeks post-PRK was used to assess changes in corneal backscatter reflectivity. Post-mortem immunohistochemistry was then performed at 2, 4 and 12 weeks post-PRK, using antibodies against α-smooth muscle actin (α-SMA). Finally, immunohistochemistry with antibodies against βIII-tubulin (Tuj-1) was performed in the same corneas to quantify changes in nerve distribution relative to unoperated, control cat corneas. Two weeks after PRK, untreated corneas exhibited the greatest amount of staining for α-SMA, followed by PA-treated and MMC-treated eyes. This was matched by higher OCT-based stromal reflectivity values in untreated, than PA- and MMC-treated eyes. PA treatment appeared to slow epithelial healing and although normal epithelial thickness was restored by 12 weeks-post-PRK, intra-epithelial nerve length only reached ∼1/6 normal values in PA-treated eyes. Even peripheral cornea (outside the ablation zone) exhibited depressed intra-epithelial nerve densities after PA treatment. Stromal nerves were abundant under the α-SMA zone, but appeared to largely avoid it, creating an area of sub-epithelial stroma devoid of nerve trunks. In turn, this may have led to the lack of sub-basal and intra-epithelial nerves in the ablation zone of PA-treated eyes 4 weeks after PRK, and their continuing paucity 12 weeks after PRK. Intra-operative MMC, which sharply decreased α-SMA staining, was followed by rapid restoration of nerve densities in all corneal layers post-PRK compared to untreated corneas. Curiously, stromal nerves appeared unaffected by the development of large, stromal, acellular zones in MMC-treated corneas. Overall, it appears that post-PRK treatments that were most effective at reducing α-SMA-positive cells in the early post-operative period benefited nerve regeneration the most, resulting in more rapid restoration of nerve densities in all corneal layers of the ablation zone and of the corneal periphery.
Collapse
Affiliation(s)
- Holly B Hindman
- The Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA; Center for Visual Science, University of Rochester, Rochester, NY, 14627, USA
| | | | - Christine Callan
- The Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Thurma McDaniel
- The Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA
| | - Tracy Bubel
- Center for Visual Science, University of Rochester, Rochester, NY, 14627, USA
| | - Krystel R Huxlin
- The Flaum Eye Institute, University of Rochester, Rochester, NY, 14642, USA; Center for Visual Science, University of Rochester, Rochester, NY, 14627, USA.
| |
Collapse
|
5
|
Savage DE, Brooks DR, DeMagistris M, Xu L, MacRae S, Ellis JD, Knox WH, Huxlin KR. First demonstration of ocular refractive change using blue-IRIS in live cats. Invest Ophthalmol Vis Sci 2014; 55:4603-12. [PMID: 24985471 DOI: 10.1167/iovs.14-14373] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the efficacy of intratissue refractive index shaping (IRIS) using 400-nm femtosecond laser pulses (blue light) for writing refractive structures directly into live cat corneas in vivo, and to assess the longevity of these structures in the eyes of living cats. METHODS Four eyes from two adult cats underwent Blue-IRIS. Light at 400 nm with 100-femtosecond (fs) pulses were tightly focused into the corneal stroma of each eye at an 80-MHz repetition rate. These pulses locally increased the refractive index of the corneal stroma via an endogenous, two-photon absorption process and were used to inscribe three-layered, gradient index patterns into the cat corneas. The optical effects of the patterns were then tracked using optical coherence tomography (OCT) and Shack-Hartmann wavefront sensing. RESULTS Blue-IRIS patterns locally changed ocular cylinder by -1.4 ± 0.3 diopters (D), defocus by -2.0 ± 0.5 D, and higher-order root mean square (HORMS) by 0.31 ± 0.04 μm at 1 month post-IRIS, without significant changes in corneal thickness or curvature. Refractive changes were maintained for the duration they were tracked, 12 months post-IRIS in one eye, and just more than 3 months in the remaining three eyes. CONCLUSIONS Blue-IRIS can be used to inscribe refractive structures into live cat cornea in vivo that are stable for at least 12 months, and are not associated with significant alterations in corneal thicknesses or radii of curvature. This result is a critical step toward establishing Blue-IRIS as a promising technique for noninvasive vision correction.
Collapse
Affiliation(s)
- Daniel E Savage
- The Institute of Optics, University of Rochester, Rochester, New York, United States Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Daniel R Brooks
- The Institute of Optics, University of Rochester, Rochester, New York, United States
| | - Margaret DeMagistris
- Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| | - Lisen Xu
- The Institute of Optics, University of Rochester, Rochester, New York, United States
| | - Scott MacRae
- Center for Visual Science, University of Rochester, Rochester, New York, United States Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| | - Jonathan D Ellis
- The Institute of Optics, University of Rochester, Rochester, New York, United States Department of Mechanical Engineering, University of Rochester, Rochester, New York, United States
| | - Wayne H Knox
- The Institute of Optics, University of Rochester, Rochester, New York, United States Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Krystel R Huxlin
- Center for Visual Science, University of Rochester, Rochester, New York, United States Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| |
Collapse
|