Publications by authors named "George P M Cheng"
Article Synopsis
- LASIK surgery can cause temporary dry eye due to nerve damage, but this study investigates long-term ocular surface changes, blinking rates, and meibomian gland health in post-LASIK patients at least 48 months post-surgery.
- The study involved 48 post-LASIK patients and 48 matched healthy controls, assessing clinical findings and imaging related to eye health.
- Findings showed that post-LASIK patients had lower meibum quality, reduced tear production, and high chronic dry eye symptom prevalence, indicating the need for thorough evaluations and treatments for affected patients.
Purpose: This study aims to report correlations between thyroid-stimulating immunoglobulin (TSI) and both clinical and radiological parameters in recent-onset symptomatic thyroid eye disease (TED) patients.
Methods: A prospective cohort study of TED patients managed at the Chinese University of Hong Kong from January 2014 to May 2022. Serum TSI levels were determined with the functional assay.
Purpose: Euthyroid Graves' ophthalmology (EGO) refers to the subgroup of thyroid eye disease patients with distinct clinical presentations. This study evaluated the ocular surface and meibomian gland changes in EGO patients.
Methods: A cross-sectional study was conducted at The Chinese University of Hong Kong including 34 EGO patients and 34 age-and sex- matched healthy controls.
Background: The retinal image quality derived from lower-order (LOA) and higher-order aberrations (HOA) for fixed 3-mm and photopic pupil diameters, in children undergoing combined 0.01% atropine and orthokeratology (AOK) versus those receiving orthokeratology alone (OK) over two years was evaluated.
Methods: The visual Strehl ratio based on the optical transfer function (VSOTF), derived from 2nd- to 4th-order terms (LOA and HOA combined), 2nd-order terms (LOA only), and 3rd- to 4th-order terms (HOA only) for fixed 3-mm and natural photopic pupil diameters, was compared between the two treatment groups.
Purpose: To compare different outcomes of an enhanced monofocal intraocular lens (IOL) versus a conventional monofocal IOL implantation after cataract surgery.
Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline was used for abstracting data and assessing quality. Comparative studies between enhanced monofocal versus conventional monofocal IOL implantations reporting outcomes in monocular and binocular visual acuities at various distances, spectacle independence, contrast sensitivity, optical quality, and adverse effects were identified from three databases.
To investigate the elastic modulus of human corneal stroma using tensile testing with optical coherence tomography (OCT) imaging and its correlation with measurements using corneal visualization Scheimpflug technology. Twenty-four corneal specimens extracted from stromal lenticules through small incision lenticule extraction were cut into strips for uniaxial tensile tests. corneal biomechanical responses were evaluated preoperatively using the corneal visualization Scheimpflug technology (CorVis ST).
View Article and Find Full Text PDFBackground: Standard epithelium-off collagen cross-linking using Dresden protocol (S-CXL) is the standard of care for progressive keratoconus. Despite its efficacy, epithelial debridement is associated with pain, delayed visual rehabilitation, stromal oedema and haze. Minimising these complications while achieving a comparable efficacy remains an unmet need.
View Article and Find Full Text PDFPurpose: To investigate environmental factors associated with corneal morphologic changes.
Methods: A cross-sectional study was conducted, which enrolled adults of the Han ethnicity aged 18 to 44 years from 20 cities. The cornea-related morphology was measured using an ocular anterior segment analysis system.
Purpose: To compare the changes in higher order aberrations (HOA's) for photopic and mesopic pupil diameters in children undergoing orthokeratology treatment (OK) or combined 0.01% atropine with orthokeratology treatment (AOK), and their association with axial elongation.
Methods: Children aged 6 to <11 years with 1.
Purpose: To investigate the long-term stability of corneal astigmatism after combined femtosecond (fs)-assisted phacoemulsification and arcuate keratotomy.
Design: Retrospective, interventional case series.
Methods: Surgery was performed using a Victus (Bausch & Lomb) platform.
Purpose: To compare higher-order aberrations (HOAs) after small incision lenticule extraction (SMILE) in patients with and without intraoperative angle kappa adjustments.
Methods: This is a retrospective case series. One hundred six eyes of 106 patients who underwent SMILE at Tianjin Eye Hospital (Tianjin Medical University, Tianjin, China) for correction of myopia and myopic astigmatism were divided into 2 groups.
Purpose: To determine the association between anterior corneal curvature and optical zone centration as well as its impact on aberration profiles in small-incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK).
Methods: Seventy-eight eyes of 78 patients treated with SMILE (45 eyes) and LASIK (33 eyes) were included. The centration of the optical zone was evaluated on the instantaneous curvature difference map between the preoperative and 3-month postoperative scans using a superimposed set of concentric circles.
Purpose: To compare the astigmatic correction in high myopic astigmatism between small-incision lenticule extraction and laser in situ keratomileusis (LASIK) using vector analysis.
Setting: Hong Kong Laser Eye Center, Hong Kong.
Design: Retrospective case series.
Determining total corneal power after small-incision lenticule extraction in myopic eyes.
J Cataract Refract Surg
November 2017
Purpose: To evaluate the methods to correct corneal power after myopic small-incision lenticule extraction (SMILE) and to estimate the preoperative corneal power based on postoperative values.
Setting: Tianjin Eye Hospital, Tianjin, China.
Design: Retrospective case series.
Background: We described a modified 'hydroexpression' technique for the lenticule removal during small-incision lenticule extraction (SMILE) surgery and compared the results with conventional forceps method.
Methods: This was a retrospective, comparative study of 50 patients who underwent SMILE surgery by the same surgeon. We compared the 1-week and 3-months postoperative results after SMILE using the hydroexpression technique with the conventional forceps technique.
Purpose: To investigate the effect of the learning curve for small-incision lenticule extraction during the first 2 years of experience.
Methods: Small-incision lenticule extraction was performed using the 500-kHz VisuMax femtosecond laser (Carl Zeiss Meditec) by the same surgeon. The initial 100 patients since the surgeon started operating independently were considered as group 1; the recent 100 patients were considered as group 2.
Purpose: To study the effect of myopia on the pattern change in higher-order aberrations after small incision lenticule extraction.
Methods: Sixty eyes of 60 patients were included: low myopia (≤-3.00 D), moderate myopia (-3.
We describe a simple steep-axis marking technique that uses a corneal analyzer (OPD III scan) during arcuate keratotomy in femtosecond laser-assisted cataract surgery. The technique requires a single reference mark at the limbus, which does not have to be on the horizontal axis. Using the corneal analyzer, the angle between the steep axis and the reference line between the reference mark and the center of the cornea can be determined.
View Article and Find Full Text PDFLaser in-situ keratomileusis (LASIK) is safe and effective laser refractive procedures in treating refractive errors. However, regression of treatment and iatrogenic keratectasia remain to be a major concern, especially in treating thin cornea with high ametropia. Collagen cross-linking (CXL) is an effective method in stopping keratoconus progression through increasing the biomechanical strength of the cornea.
View Article and Find Full Text PDFWe compared the visual and refractive outcomes between 2 different incisional sites in small incision lenticule extraction (SMILE) for low myopic astigmatism. This was a contralateral eye study. Consecutive cases that underwent bilateral SMILE surgery were included.
View Article and Find Full Text PDFPurpose: To analyze the visual and refractive outcomes of LASIK with and without simultaneous cross-linking for correction of myopia.
Methods: Patients who received femtosecond laser-assisted LASIK with and without adjunctive cross-linking according to patient's preference were examined longitudinally for 6 months. Patients with myopic manifest refraction spherical equivalent of 5.
We prospectively compared visual and refractive outcomes in patients with high myopia and myopic astigmatism after small-incision lenticule extraction (SMILE) and photorefractive keratetctomy (PRK) with mitomycin C. Sixty-six eyes of 33 patients (mean age, 29.7 ± 5.
View Article and Find Full Text PDFArticle Synopsis
- The study aimed to compare the changes in corneal biomechanical properties after two surgical methods: microincision lenticule extraction (MILE) with a 2 mm incision and small incision lenticule extraction (SMILE) with a 5 mm incision.
- Results showed significant decreases in corneal hysteresis (CH) and corneal resistance factor (CRF) for both procedures, but the MILE procedure had a less pronounced reduction in these parameters following surgery.
- The findings suggest that while both MILE and SMILE affect corneal biomechanics, the smaller incision used in MILE may lead to better early postoperative corneal stability.
Purpose: To investigate the stability of corneal astigmatism and higher-order aberrations after combined femtosecond-assisted phacoemulsification and arcuate keratotomy.
Design: Retrospective, interventional case series.
Methods: Surgery was performed using a VICTUS (Bausch & Lomb Inc, Dornach, Germany) platform.
Background. To compare the early outcome of combined SMILE and collagen crosslinking (SMILE Xtra) with SMILE. Method.
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