Publications by authors named "Srivannaboon S"
Purpose: To evaluate the accuracy of axial length (AL) measurement for intraocular lens (IOL) calculation in patients with cataract and epiretinal membrane (ERM).
Methods: This prospective, cross-sectional study was performed in cataract patients with ERM. All subjects were sent for standard optical biometry, prepared for cataract surgery.
Automation and population aging are two major forces that will shape the nature of works in the future. However, it is not clear how these forces will interact with each other and affect the labor market. This paper examines the interaction effects of computerization and population aging on the labor market.
View Article and Find Full Text PDFThis paper empirically examines jumps and cojumps of both major and minor cryptocurrencies. Understanding the nature of their jumps and cojumps plays an important role in risk management, asset allocation and pricing of derivatives. We find that all cryptocurrencies display significant jumps.
View Article and Find Full Text PDFSignificance: A major limitation of standard time-domain optical coherence tomography-based biometers (TD-OCT) is an inability to measure the axial length (AL) in advanced cataract. A new device that uses swept-source optical coherence tomography (SS-OCT) allows better light penetration. Hence, a considerable number of cataract patients who failed AL measurement by TD-OCT can be recovered by SS-OCT.
View Article and Find Full Text PDFComparison of refractive outcomes using conventional keratometry or total keratometry for IOL power calculation in cataract surgery.
Graefes Arch Clin Exp Ophthalmol
December 2019
Article Synopsis
- The study compared the refractive outcomes of cataract surgery using conventional keratometry (K) versus total keratometry (TK) for calculating intraocular lens (IOL) power across various formulas in 60 patients.
- Both K and TK produced very similar IOL powers, but TK showed slightly lower mean absolute errors and better refractive outcomes, particularly with the Barrett TK Universal II formula.
- The findings suggest that both K and TK are reliable for IOL calculations, with TK potentially offering some improvements in accuracy.
Purpose: We report a rare case of ocular injury due to potassium permanganate (KMnO) granules in a child.
Methods: This is a retrospective case report.
Results: A 2-year-old boy was transferred to our emergency room with severe pain in his right eye, inflamed eyelids, and brownish stains on his fingers.
Article Synopsis
- The study aimed to assess the accuracy and consistency of a new optical biometer (IOLMaster 700) compared to a traditional one (IOLMaster 500) in cataract patients.
- The research involved 100 eyes measured by both devices, focusing on various ocular parameters and calculating intraocular lens (IOL) power using different formulas.
- Results showed that the new biometer demonstrated excellent repeatability and reproducibility, with high agreement on measurements and superior performance in specific cases, particularly in challenging conditions with dense cataracts.
Article Synopsis
- The study aimed to compare corneal astigmatism measurements from a new optical biometer (AL-Scan) with a standard biometer (IOLMaster 500) for selecting toric intraocular lenses in cataract patients.
- Conducted at Siriraj Hospital, Bangkok, the study involved 137 eyes and utilized keratometry readings from both devices, analyzing data for agreement and correlation between measurements.
- Results showed similar astigmatism magnitudes from both devices in the 2.4 mm zone, while differences were noted in the 3.3 mm zone; overall, toric IOL selections were consistent between devices.
Article Synopsis
- - The study aimed to compare the accuracy and consistency of eye measurements and IOL power calculations using a new optical biometer (AL-Scan) versus a standard one (IOLMaster 500) at Siriraj Hospital, Bangkok.
- - Measurements included various ocular metrics from 137 eyes in 81 patients, with results showing high repeatability and reproducibility for both devices, except for the white-to-white corneal diameter, which had lower agreement.
- - Both devices produced similar IOL power calculations, indicating that the new optical biometer is a reliable alternative for ocular biometry in clinical settings.
Accuracy of Holladay 2 formula using IOLMaster parameters in the absence of lens thickness value.
Graefes Arch Clin Exp Ophthalmol
November 2013
Background: The accuracy of the Holladay 2 (H2) formula is well-documented. This formula requires seven variables to estimate effective lens position (ELP) for the IOL power calculation. The lens thickness (LT) value is one of the required variables.
View Article and Find Full Text PDFBackground: The accurrate and expedient ocular biometry is essential for modern cataract surgery. IOLMaster 500, one of the most popular partial coherence interferometry (PCI) device, has been widely used. However, with the PCI device, it is difficult to obtain the axial length through densely opaque media.
View Article and Find Full Text PDFPurpose: To compare the corneal astigmatism (magnitude and axis location) derived by total corneal power (TCP), automated keratometry, and simulated keratometry.
Setting: Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Design: Prospective comparative study.
Purpose: To evaluate the difference in the spherical aberration (SA) induced by an aspheric and a non-aspheric myopic ablation profile with the MEL80 excimer laser (Carl Zeiss Meditec).
Methods: This was a prospective randomized paired-eye controlled study of 15 patients (30 eyes) who underwent LASIK using the Hansatome microkeratome (160 μm) (Bausch & Lomb) and the MEL80 using a 6 mm optical zone. For each patient, one eye was treated with an aspheric (Aberration Smart Ablation [ASA]) profile and the other eye was treated with a non-aspheric (Tissue Saving Ablation [TSA]) profile, assigned at random.
Objective: To evaluate refractive outcomes of myopic femtosecond LASIK at Siriraj Hospital, Thailand.
Material And Method: A retrospective study of patients who underwent femtosecond LASIK at SiLASIK center Siriraj hospital, Mahidol University, Thailand,from April 2009 to April 2010 was conducted. All patients had completely normal preoperative eye examination.
Purpose: To evaluate the repeatability and reproducibility of posterior corneal curvature and posterior corneal elevation best-fit sphere (BFS) obtained with the Visante Omni (Carl Zeiss Meditec) and to compare the results with the Orbscan II (Bausch & Lomb).
Methods: Thirty eyes from 30 healthy volunteers were included in this study. All patients were examined 5 times with the Visante Omni and Orbscan II by 2 independent operators.
Objective: To develop a scale for measuring refractive error quality of life (QOL) for Thai adults.
Material And Method: The full survey comprised 424 respondents from 5 medical centers in Bangkok and from 3 medical centers in Chiangmai, Songkla and KhonKaen provinces. Participants were emmetropes and persons with refractive correction with visual acuity of 20/30 or better An item reduction process was employed by combining 3 methods-expert opinion, impact method and item-total correlation methods.
Purpose: To characterize changes in the corneal epithelial thickness profile induced by myopic LASIK.
Methods: This was a prospective study of 37 eyes of 19 myopic LASIK patients. Eyes were divided into three groups according to sphere in the maximum myopic meridian: low (-1.
Purpose: To estimate the posterior corneal power for intraocular lens (IOL) calculation after myopic LASIK.
Methods: A retrospective study of 50 patients (92 eyes) who underwent uneventful myopic LASIK was conducted. Pre- and postoperative data (12 months) were collected including refraction and Orbscan II (Bausch & Lomb) for simulated keratometry (Sim K), central corneal thickness, and posterior corneal power.
Objective: To compare the performance of the Conventional Biometry (CB) (Applanation Ultrasound and Keratometry) and the Integrated Laser Interferometry with Keratometry Device (LI) in the measurement of Intraocular Lens (IOL).
Material And Method: A prospective study of 100 eyes in 50 cataract patients was conducted. The IOL measurement using the LIfollowed by the CB was done on all eyes.
Purpose: To evaluate diurnal variation of higher order aberrations in human eyes.
Methods: A prospective study of 20 myopic eyes was performed. Cycloplegic aberrometry (Zywave) and refraction were measured at 2-hour intervals for five time points beginning at 10:00 AM.
Purpose: To derive a statistical model to estimate the rate of excessive keratectomy depth below a selected cut-off residual stromal thickness (RST) given a minimum target RST and specific Clinical Protocol; apply the model to estimate the RST below which ectasia appears likely to occur and back-calculate the safe minimum target RST that should be used given a specific Clinical Protocol.
Methods: Myopia and corneal thickness distribution were modeled for a population of 5212 eyes that underwent LASIK. The probability distribution of predicted target RST error (Part I) was used to calculate the rate of excessive keratectomy depth for this series.
Purpose: To measure the imprecision of microkeratome cuts, preoperative corneal pachymetry, and laser ablation depth and develop a statistical model to describe the probability of the residual stromal bed thickness (RST) after myopic LASIK being significantly thinner than predicted.
Methods: Preoperative corneal thickness, flap thickness, ablation depth, and RST were measured in 36 eyes by a prototype three-dimensional very high-frequency (VHF) 50 MHz digital ultrasound scanning device (<1.2 microm precision), precursor to the commercially available Artemis 2.
Purpose: To present a method that determines the efficacy of flap creation using a microkeratome.
Methods: Thirty-six eyes of 18 patients were included in the study, operated by two experienced surgeons using the Moria LSK-One microkeratome. Very high-frequency (VHF) digital ultrasound arc-scanning using Artemis technology was used to measure the Reinstein Flap Thickness Profile created by addition of the preoperative epithelial thickness profile to the postoperative stromal component of the flap.
Objectives: To evaluate the effect of unfocused measurement in the value of ocular aberrations.
Material And Method: The present study was conducted at Siriraj Hospital, Mahidol University. Ocular aberrations of 20 eyes in 10 myopic patients (myopia less than -6.