Publications by authors named "Asimellis G"

Approximately 41% of adults aged 18-24 years in the United States are enrolled in a college or university (1). Wearing a face mask can reduce transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (2), and many colleges and universities mandate mask use in public locations and outdoors when within six feet of others. Studies based on self-report have described mask use ranging from 69.

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Background: Femtosecond-laser assisted clear cornea cataract surgery may hold promise in safer and more effective procedures. We decided to perform a comparative study to standard manual incision phacoemulsification surgery.

Methods: This is a single-center, single-intervention, and prospective comparative data evaluation of 133 consecutive cases subjected to cataract surgery.

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Background: To compare intraocular pressure (IOP) changes following topical dexamethasone administration for 1 month in keratoconic versus normal eyes.

Methods: This is a retrospective, single-center, non-randomized case series evaluation of 350 eyes. Two groups were formed: normal/control Group A (nA =73), eyes that underwent excimer laser photorefractive keratectomy; and keratoconic (KCN) Group B (nB =277), eyes that were subjected to partial laser photorefractive keratectomy combined with collagen cross-linking (The Athens Protocol).

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Purpose: To evaluate ex vivo the possible difference in corneal cross-linking (CXL) biomechanical effect of different ultraviolet-A (UV-A) irradiances.

Methods: The study involved 25 human donor corneas, randomly allocated to 5 groups (n = 5 each). CXL was applied with UV-A irradiances of 3, 9, 18, 30, and 45 mW/cm2, maintaining equal cumulative energy dose of 5.

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Dry eye is a multifactorial, progressive, and chronic disease of the tears and ocular surface. The disease is multi-factorial and has intermittent symptoms. Discomfort, visual disturbance, tear film instability with potential damage to the ocular surface, and increased tear film osmolarity are known associates.

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Purpose: To comparatively investigate the efficacy of the enhanced Athens Protocol procedure guided by novel Placido-derived topography with cyclorotation compensation (the cyclorotation adjusted group) to similar cases guided by Scheimpflug-derived tomography without cyclorotation compensation (the non-cyclorotation adjusted group).

Methods: Two groups were evaluated: the cyclorotation adjusted group (n = 110 eyes) and the non-cyclorotation adjusted group (n = 110 eyes). Analysis was based on digital processing of Scheimpflug imaging derived curvature difference maps preoperatively and 3 months postoperatively.

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Purpose: To evaluate corneal stromal thickness reduction and compare to attempted and achieved ablation depth in a consecutive case series study of myopic LASIK.

Methods: Stromal thickness reduction was retrospectively evaluated in 205 consecutive eyes of 205 patients undergoing myopic and myopic astigmatic LASIK. Anterior segment optical coherence tomography was performed preoperatively and 3 months postoperatively.

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Purpose: To evaluate the safety, efficacy, and refractive and keratometric stability of myopic femtosecond laser in situ keratomileusis (LASIK) with concurrent prophylactic high-fluence corneal collagen crosslinking (CXL) compared with the outcomes of standard femtosecond LASIK.

Setting: Private clinical practice, Athens, Greece.

Design: Consecutive randomized prospective comparative study.

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Purpose: To evaluate and investigate the distribution and repeatability of anterior corneal surface astigmatism measurements (axis and magnitude) using a novel corneal topographer.

Methods: Anterior corneal surface astigmatism was investigated in a total of 195 eyes using a novel multicolored spot reflection topographer (Cassini; i-Optics). Two patient groups were studied, a younger-age group A and an older-age group B.

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Background/aims: To evaluate ex vivo biomechanical and enzymatic digestion resistance differences between standard myopic laser in-situ keratomileusis (LASIK) compared with LASIK+CXL, in which high-irradiance cross-linking (CXL) is added.

Methods: Eight human donor corneas were subjected to femtosecond-assisted myopic LASIK. Group A (n=4) served as a control group (no CXL).

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Purpose: To objectively define the effective centration of myopic femtosecond laser-assisted LASIK ablation pattern, evaluate the difference between achieved versus planned excimer laser ablation centration, and compare these results from two different generations of an excimer laser system.

Methods: The study retrospectively evaluated 280 eyes subjected to myopic LASIK. Digital image analysis was performed on Scheimpflug sagittal curvature maps (difference of preoperative to postoperative).

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Purpose: To investigate repeatability of steep and flat keratometry measurements, as well as astigmatism axis in cohorts with normal range and regular astigmatic such as: eyes following laser-assisted in situ keratomileusis (LASIK) and normal population, as well as cohorts of high and irregular astigmatism such as keratoconic eyes, and keratoconic eyes following corneal collagen cross-linking, employing a novel corneal reflection topography device.

Methods: Steep and flat keratometry and astigmatism axis measurement repeatability was investigated employing a novel multicolored-spot reflection topographer (Cassini) in four study groups, namely a post myopic LASIK-treated Group A, a keratoconus Group B, a post-CXL keratoconus Group C, and a control Group D of routine healthy patients. Three separate, maps were obtained employing the Cassini, enabling investigation of the intra-individual repeatability by standard deviation.

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Purpose: To compare postoperative changes in apparent photopic and mesopic pupil size and centration in relation to cornea reflection landmarks after cataract surgery.

Setting: LaserVision.gr Clinical and Research Eye Institute, Athens, Greece.

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Purpose: To evaluate biomechanical changes induced by in situ corneal cross-linking (CXL) with stromal pocket delivered enhanced concentration riboflavin and high-fluence, high-energy UV-A irradiation.

Methods: Eight human donor corneas were subjected to intrastromal lamellar corneal tissue removal of anterior 140-μm deep, 80-μm thick × 5-mm diameter central stromal buttons, extracted through a 3.5-mm width tunnel, surfacing in the superior cornea periphery.

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Purpose: To report novel application of topographically-customized collagen crosslinking aiming to achieve hyperopic refractive changes. Two approaches were evaluated, one based on epithelium-off and one based on epithelium-on (transepithelial).

Methods: A peripheral annular-shaped topographically customizable design was employed for high-fluence ultraviolet (UV)-A irradiation aiming to achieve hyperopic refractive changes.

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Purpose: To compare 1-year results: safety, efficacy, refractive and keratometric stability, of femtosecond myopic laser-assisted in situ keratomileusis (LASIK) with and without concurrent prophylactic high-fluence cross-linking (CXL) (LASIK-CXL).

Methods: We studied a total of 155 consecutive eyes planned for LASIK myopic correction. Group A represented 73 eyes that were treated additionally with concurrent prophylactic high-fluence CXL; group B included 82 eyes subjected to the stand-alone LASIK procedure.

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Purpose: To investigate epithelial thickness-distribution characteristics in a large group of keratoconic patients and their correlation to normal eyes employing anterior-segment optical coherence tomography (AS-OCT).

Materials And Methods: The study group (n=160 eyes) consisted of clinically diagnosed keratoconus eyes; the control group (n=160) consisted of nonkeratoconic eyes. Three separate, three-dimensional epithelial thickness maps were obtained employing AS-OCT, enabling investigation of the pupil center, average, mid-peripheral, superior, inferior, maximum, minimum, and topographic epithelial thickness variability.

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Article Synopsis
  • This case report evaluates a new multicolored-spot reflection topographer for imaging the corneal surface, comparing it with four established imaging systems.
  • A 17-year-old girl with chronic herpetic keratitis in her left eye was studied, revealing that traditional systems struggled to accurately image her condition due to various limitations.
  • The findings suggest that the novel topographer could be a reliable option for corneal imaging in challenging cases, highlighting its potential for improving clinical outcomes in ophthalmology.
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Purpose: To investigate, by high-precision digital analysis of data provided by Scheimpflug imaging, changes in pupil size and shape and anterior chamber (AC) parameters following cataract surgery.

Patients And Methods: The study group (86 eyes, patient age 70.58±10.

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Article Synopsis
  • The study aimed to compare corneal thickness asymmetry indices in keratoconus patients using anterior segment optical coherence tomography (AS-OCT) against traditional Scheimpflug imaging methods.
  • Six specific corneal indices were analyzed across two groups: 175 keratoconic eyes and 175 control eyes, with significant differences noted between the two groups.
  • Results showed significant correlations between AS-OCT indices and established Scheimpflug indices, suggesting that AS-OCT could be a reliable method for assessing early stages of keratoconus.
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Purpose: To determine 3-dimensional corneal pachymetry distribution characteristics in a large pool of healthy normal patients.

Setting: Private practice, Athens, Greece.

Design: Prospective case series.

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Purpose: To compare epithelial remodeling in keratoconic eyes that had photorefractive keratectomy and corneal collagen crosslinking (Athens protocol) with that in untreated keratoconic eyes and healthy eyes.

Setting: Private clinical practice, Athens, Greece.

Design: Comparative case series.

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