-
BMC Ophthalmology Jan 2023To evaluate corneal topography and densitometry features in patients with polycystic ovary syndrome (PCOS) and compare them with healthy individuals.
BACKGROUND
To evaluate corneal topography and densitometry features in patients with polycystic ovary syndrome (PCOS) and compare them with healthy individuals.
METHODS
53 eyes of 53 female patients diagnosed with PCOS and 53 eyes of 53 age-matched female volunteers were analyzed in the study. In addition to the detailed ophthalmological and gynecological examination, anterior segment analysis was performed using Pentacam. A complete analysis of aberrometric, keratometric, topometric, and, densitometric values between the groups was performed, and the results were outlined.
RESULTS
According to the results, although Kmax-front, Kmean-front, ISV, IVA, IHA, BAD_D and PI-Avg values were slightly higher in PCOS group along with a slight thinning in the thinnest location, there was no statistically significant difference between the groups. Moreover, correlation analysis between PCOS clinical parameters and keratometric/topometric/aberrometric data were found to be almost normal. Yet, when Pentacam tomography maps of all cases are examined in detail, mild ectatic changes were observed in 5 cases in PCOS group. Furthermore, a significant increase in thickness across all densitometry values except anterior (10-12 mm), central (10-12 mm), and total (10-12 mm) was found in PCOS group.
CONCLUSIONS
Our study showed that an intensification of corneal densitometry values and various changes in keratometry data implying ectasia can be observed in patients with PCOS. Prospective studies with larger patient series are needed to reveal any potential relationship between PCOS and corneal abnormalities.
Topics: Humans; Female; Corneal Topography; Polycystic Ovary Syndrome; Prospective Studies; Cornea; Corneal Pachymetry; Densitometry; Dilatation, Pathologic; Keratoconus
PubMed: 36597084
DOI: 10.1186/s12886-022-02758-4 -
PloS One 2022To quantify changes in corneal densitometry after long-term orthokeratology treatment in myopic children and to analyze the reversibility one month after discontinuation.
PURPOSE
To quantify changes in corneal densitometry after long-term orthokeratology treatment in myopic children and to analyze the reversibility one month after discontinuation.
METHODS
Seventy-four myopic subjects aged 8-16 years, who wore orthokeratology lenses for two years, were divided into relatively steep- (lens movement within 1.0-1.5 mm, thirty-six participants) and flat-fitting groups (lens movement within 1.5-2.0 mm, thirty-eight participants). Based on refractive errors, they were divided into low and moderate myopia groups (thirty-seven participants in each group). Corneal densitometry was performed using Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) at each follow-up timepoint. Repeated-measures analysis of variance was used to compare the parameters before and after orthokeratology.
RESULTS
The corneal densitometry values over the 0-10 mm diameter area increased from 12.84±1.38 grayscale units (GSU) at baseline to 13.59±1.42 GSU after three-month orthokeratology (P = .001) and reached 14.92±1.45 GSU at two years (P < .001). An increase in densitometry began at one month (P = .001) over the 0-2 mm annulus compared with that at three months over the 2-6 mm and 6-10 mm zones (P = .002,.014). The densitometry values significantly increased at three months in the relatively steep-fitting group (P = .003) and at one year in the relatively flat-fitting group (P = .001). After discontinuation of orthokeratology for one month, the values showed no significant decrease.
CONCLUSIONS
Long-term orthokeratology treatment causes a small but statistically significant increase in corneal densitometry values. During the first year, the onset of these changes was related to the fitting mode. Corneal densitometry values showed no significant reduction after one-month discontinuation.
Topics: Adolescent; Child; Contact Lenses; Cornea; Corneal Topography; Densitometry; Female; Humans; Male; Myopia; Orthokeratologic Procedures; Refraction, Ocular; Refractive Errors; Retrospective Studies; Treatment Outcome
PubMed: 35120161
DOI: 10.1371/journal.pone.0263121 -
Eye (London, England) Aug 2022To describe a new algorithm to measure corneal densitometry based on images obtained by swept source anterior segment ocular coherence tomography (SS-AS-OCT) and...
PURPOSE
To describe a new algorithm to measure corneal densitometry based on images obtained by swept source anterior segment ocular coherence tomography (SS-AS-OCT) and establish standard densitometry values in a group of normal eyes.
METHODS
A total of 111 healthy participants (195 eyes) were enrolled in this study. Using a MATLAB designed algorithm, the cornea was segmented into three layers: anterior, posterior and mid-stroma, and it was divided into two concentric areas, 0-2 and 2-4 mm, resulting in nine areas for the analysis. The mean corneal densitometry values were calculated and expressed as grayscale units (GSU).
RESULTS
The mean age was 57 years (range 22-87), with 100 (51.3%) right eyes and 95 (48.7%) left eyes. The total corneal densitometry was 86.9 ± 12.1 GSU. The mid-stroma layer had the highest densitometry values, 87.4 ± 12.1 GSU, and the anterior layer had the lowest values, 81.9 ± 14.2 GSU. Densitometry differences between the anterior layer and the mid-stroma layer (P < 0.001), as well as the anterior layer and the posterior layer (P < 0.05) were statistically significant. The 0-2 mm concentric area had higher mean densitometry values, 97.8 ± 12.7 GSU, and the differences were significant compared to the 2-4 mm concentric area (P < 0.001). No correlation was found between the corneal densitometry values and gender or age.
CONCLUSIONS
The new MATLAB segmentation algorithm for the analysis of corneal SS-AS-OCT images is capable to objectively assess corneal densitometry. We provide standard and normal data for better clinical and research approach.
Topics: Adult; Aged; Aged, 80 and over; Algorithms; Cornea; Corneal Topography; Densitometry; Healthy Volunteers; Humans; Middle Aged; Tomography, Optical Coherence; Young Adult
PubMed: 34341484
DOI: 10.1038/s41433-021-01707-7 -
BMC Ophthalmology Jul 2018To investigate corneal densitometry values obtained using Scheimpflug tomography in normal and highly myopic (HM) eyes and to assess the differences in densitometry...
BACKGROUND
To investigate corneal densitometry values obtained using Scheimpflug tomography in normal and highly myopic (HM) eyes and to assess the differences in densitometry values between them.
METHODS
Highly myopic and normal corneas were examined using the Pentacam Scheimpflug imaging system. Corneal densitometry was automatically performed over a 12-mm diameter area, which was divided on the basis of annular concentric zones (0-2 mm, 2-6 mm, 6-10 mm, 10-12 mm, total diameter) and depth (anterior layer: inner 120 μm; center layer: from 120 μm to the last 60 μm; posterior layer: last 60 μm; total corneal thickness).
RESULTS
A total of 100 normal and 100 HM eyes were enrolled in this study. Upon total corneal thickness densitometry, the HM group was found to have significantly lower values compared with the normal group in 4 annuli, including the 2 mm central zone, 2-6 mm zone, 6-10 mm zone, and 0-12 mm total diameter. Upon anterior layer densitometry, the HM group demonstrated statistically lower values in the 2-6 mm and 6-10 mm zones. Upon densitometry of the central and posterior layers, the HM group was found to have lower values in all annuli.
CONCLUSIONS
The densitometry map reveals that light backscatter was lower in most portions of the HM cornea than in the normal cornea.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cornea; Corneal Pachymetry; Corneal Topography; Densitometry; Elasticity; Female; Humans; Male; Middle Aged; Myopia; Visual Acuity; Young Adult
PubMed: 30045701
DOI: 10.1186/s12886-018-0851-x -
Graefe's Archive For Clinical and... Apr 2021To assess corneal densitometry in patients with Fabry disease (FD) and to compare corneal densitometry differences in FD patients to different corneal manifestations.
PURPOSE
To assess corneal densitometry in patients with Fabry disease (FD) and to compare corneal densitometry differences in FD patients to different corneal manifestations.
METHODS
Ten participants (20 eyes) with FD and 10 age-matched healthy volunteers (20 eyes) were recruited. All participants were assessed by standardized ophthalmic examinations and the corneal densitometry analysis by Pentacam HR. Densitometry measurements were analyzed in standardized grayscale units.
RESULTS
Seven patients developed conjunctival vessel tortuosity, cornea verticillata appeared in 6 patients, and two patients had Fabry cataract. Retinal vessel tortuosity occurred in 4 patients, and dilation of retinal vessels appeared in 3 patients, all symptoms occurred in both eyes. The first diagnosis of FD up to examination was 4.7 ± 3.23 years, and first ERT up to examination was 2.6 ± 2.27 years. The initial time to diagnosis was negatively related to the corneal densitometry value of the 0-2-mm (r = - 0.556, p = 0.011) and 2-6-mm (r = - 0.482, p = 0.032) zones in the posterior layer. FD group have significantly higher corneal densitometry in anterior 0-2-mm zone and 2-10-mm zone anterior and posterior layer than the control group (p ≤ 0.035, respectively). When divided into two groups by the existence of cornea verticillata, there was a statistically significant difference in the anterior layer, 6-10-mm zone (p = 0.031); in the central layer, 0-2 mm (p = 0.012), 2-6 mm (p = 0.001), 6-10 mm (p = 0.002), and total (p = 0.002); and in the posterior layer, 6-10 mm (p = 0.004) and total (p = 0.002).
CONCLUSIONS
FD patients show higher corneal densitometry, and corneal densitometry may have potential for early diagnosis and reminding progress of FD.
Topics: Conjunctiva; Cornea; Densitometry; Early Diagnosis; Fabry Disease; Humans
PubMed: 33258999
DOI: 10.1007/s00417-020-05027-6 -
Osteoporosis International : a Journal... Sep 2020In a global survey of fracture liaison services, most reported that DXA access met needs. However, adherence to basic DXA quality and reporting procedures was confirmed...
UNLABELLED
In a global survey of fracture liaison services, most reported that DXA access met needs. However, adherence to basic DXA quality and reporting procedures was confirmed by only around 50% of institutions and many required education for operators/interpreters. Overall, there is significant variability in the access to, and quality of, DXA services worldwide.
INTRODUCTION
While the use of dual-energy X-ray absorptiometry (DXA) has been widely adopted worldwide for the assessment of bone mineral density, the quality of DXA facilities is unknown. To address this, a global survey of fracture liaison services (FLS) was conducted by the International Society for Clinical Densitometry (ISCD) and the International Osteoporosis Foundation (IOF) to assess the quality of their DXA facilities.
METHODS
A questionnaire for the accessibility and quality of DXA services was co-created by representatives of the ISCD and the IOF and made available to institutions who participated in the Capture the Fracture Best Practice Framework. From a list of 331 contacted invitees, 124 FLS centres responded; analyses were based on 121 centres with suitable data.
RESULTS
Over 70% of institutions reported that, for over 90% of the time, DXA access met service needs, and the scanning/reporting quality was perceived as excellent. However, 25% of DXA facilities reported not being accredited by a professional/governmental organization, and adherence to some basic DXA quality assurance and reporting procedures was confirmed by < 50% of services. Importantly, in excess of 50% of institutions stated that they desired ongoing education in osteoporosis and DXA for operators and interpreters.
CONCLUSION
There is significant variability in the access to and quality of DXA services for established FLS worldwide. Despite two decades of training initiatives in osteoporosis densitometry, many centres are falling short of the standards of the IOF-ISCD Osteoporosis Essentials criteria.
Topics: Absorptiometry, Photon; Bone Density; Fractures, Bone; Humans; Osteoporosis; Surveys and Questionnaires
PubMed: 32377806
DOI: 10.1007/s00198-020-05435-8 -
Clinical & Experimental Optometry Mar 2021Understanding the reduction in clarity of the ocular media in patients with chronic obstructive pulmonary disease (COPD) will aid interpretation of ocular examinations...
CLINICAL RELEVANCE
Understanding the reduction in clarity of the ocular media in patients with chronic obstructive pulmonary disease (COPD) will aid interpretation of ocular examinations and refractive assessments in patients with this condition.
BACKGROUND
To investigate corneal and lens densitometry measurements of patients with COPD and to compare the results obtained with those in healthy adults.
METHODS
This prospective cross-sectional study included 25 newly diagnosed COPD patients (COPD group) and 35 healthy subjects (control group). The COPD patients were excluded if they ever had any recorded systemic or inhaler steroid therapy. After recording demographic and clinical characteristics, eligible study subjects underwent a through ophthalmic evaluation which included measurement of refractive errors using the same automatic refractor-keratometer device, best-corrected visual acuity determination using a Snellen chart, measurement of intraocular pressure using a pneumotonometer, slitlamp biomicroscopy and fundus examination. After general ophthalmic examination, the Pentacam HR imaging system was used to evaluate corneal and lens densitometry measurements of the groups.
RESULTS
There were no statistically significant differences in the ages and genders of the participants between the two groups (p > 0.05). Additionally, the mean values of intraocular pressure, refractive error and body mass index as well as smoking status were similar between the groups (p > 0.05, for all). The mean corneal densitometry values were also similar in all the concentric zones and layers in the eyes of the patients with COPD and controls (p > 0.05, for all). However, the mean values of zones 1, 2 and 3, and average lens densitometry measurements of the COPD group, were statistically significantly higher compared to control subjects (p < 0.05, for all).
CONCLUSION
Lens clarity of patients with COPD was significantly decreased while corneal densitometry measurements were not significantly affected.
Topics: Adult; Cornea; Corneal Topography; Cross-Sectional Studies; Densitometry; Female; Humans; Male; Prospective Studies; Pulmonary Disease, Chronic Obstructive
PubMed: 32808311
DOI: 10.1111/cxo.13127 -
Turkish Journal of Ophthalmology Aug 2023To investigate the effects of pupil diameter on the evaluation of lens and corneal densitometry measured by Scheimpflug tomography.
OBJECTIVES
To investigate the effects of pupil diameter on the evaluation of lens and corneal densitometry measured by Scheimpflug tomography.
MATERIALS AND METHODS
This cross-sectional and comparative study used the right eyes of 32 participants. Corneal and lenticular optical densitometries, corneal volume, anterior segment volume, and anterior chamber depth measurements were taken with the Scheimpflug imaging system when the pupils were mid-dilated and fully dilated. The results were statistically compared.
RESULTS
The mean lens density was 19.20±3.05 when the pupils were mid-dilated (mean pupil diameter 2.98±0.89 mm) and 23.25±3.88 at full dilation (mean pupil diameter 5.01±0.92 mm) (p<0.001). The mean corneal density was 16.15±0.99 with mid-dilated pupils and 16.38±0.95 with fully dilated pupils (p=0.065). Anterior chamber depth and anterior segment volume measurements increased with larger pupil diameter (p<0.05).
CONCLUSION
The lens densitometry values increased with an increase in pupil diameter. The corneal density measurements increased minimally but the differences were not statistically significant. This study revealed that lens densitometry was significantly affected by pupil diameter.
Topics: Humans; Cross-Sectional Studies; Cornea; Pupil; Densitometry
PubMed: 37602578
DOI: 10.4274/tjo.galenos.2022.42724 -
Journal of Nuclear Medicine : Official... Dec 2000From 1990 to 2000, several effective new treatments were introduced for the prevention of osteoporotic fractures; these treatments were proven effective in large,... (Review)
Review
From 1990 to 2000, several effective new treatments were introduced for the prevention of osteoporotic fractures; these treatments were proven effective in large, international, clinical trials. At the same time, there was rapid technologic innovation, with the introduction of new radiologic methods for the noninvasive assessment of patients' bone density status. These developments led to the publication of guidelines for the clinical use of bone densitometry that include criteria for the referral of patients for investigation as well as recommendations for intervention thresholds for the initiation of preventive treatment of osteoporosis. Dual-energy x-ray absorptiometry scanning of the spine and hip remains the technique of choice for bone densitometry studies, although there is now a wider appreciation of the need for smaller, cheaper devices for scanning the peripheral skeleton if the millions of women most at risk of a fragility fracture are to be identified and treated. This article reviews these developments, concentrating in particular on the advantages and disadvantages of the different types of equipment available for performing bone densitometry investigations, the guidelines for the referral of patients, and the principles for the interpretation of the scan findings.
Topics: Absorptiometry, Photon; Bone Density; Bone Diseases, Metabolic; Female; Humans; Osteoporosis, Postmenopausal; Tomography, X-Ray Computed; Ultrasonography
PubMed: 11138687
DOI: No ID Found -
Molecules (Basel, Switzerland) Aug 2020Histamine poisoning is a significant public health problem. Therefore, the monitoring of histamine content in fish and fishery products is considered to be a crucial...
Histamine poisoning is a significant public health problem. Therefore, the monitoring of histamine content in fish and fishery products is considered to be a crucial measure in the seafood industry. In the present study, a simple and rapid densitometric thin-layer chromatographic (TLC) method for histamine determination in fish samples was developed and validated. The samples were homogenized with 10% trichloroacetic acid and histamine was efficiently extracted. Then, an appropriate derivatization procedure was adopted with dansyl chloride. Once the derivatization was carried out, the samples were applied to silica gel TLC plates and developed by ascending chromatography with chloroform-triethylamine (6:4, /) as the mobile phase. The intensity of the histamine-dansyl derivative spots was measured by densitometry at 365 nm, and the quantitation was performed by BIO-1D image processing software. The validation of this method revealed good linearity and specificity over a concentration range from 6.25 to 100 mg/kg. Adequate precision was shown by relative standard deviations (RSD) smaller than 4.82%, accuracy ranged from -6.88% to 5.28%, and satisfactory recoveries ranging from 93% to 105% were obtained. The Limit of Detection and the Limit of Quantification were calculated at 4.4 mg/kg and 10.5 mg/kg, respectively. In addition, the effectiveness of the proposed method was assessed by the analysis of various samples, and the obtained results were confirmed with those achieved by the HPLC-UV method. Moreover, the developed method was found to be simple, cheap, and suitable for application to analyze several samples simultaneously.
Topics: Animals; Chromatography, Thin Layer; Densitometry; Fisheries; Fishes; Food Analysis; Food Contamination; Histamine; Limit of Detection; Time Factors
PubMed: 32784469
DOI: 10.3390/molecules25163611