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Clinical & Experimental Optometry Sep 2002Microspherophakia is present when the crystalline lens is small and relatively spherical with increased antero-posterior thickness. Clinical findings for a patient with... (Review)
Review
Microspherophakia is present when the crystalline lens is small and relatively spherical with increased antero-posterior thickness. Clinical findings for a patient with idiopathic bilateral microspherophakia are described. The patient was moderately myopic with slightly reduced visual acuity. The anterior chambers (R: 1.57 and L: 1.37 mm) were shallow compared with normals (3.46 to 3.80 mm) and the crystalline lenses were thicker (R: 4.77 and L: 4.89 mm) than normal (3.3 to 3.96 mm) with steeper than normal anterior (radii of curvature R: 6.2 and L: 6.3 mm) and posterior (R: 6.3 and L: 5.6 mm) surfaces. Microspherophakia may be associated with various syndromes and there is a strong possibility of glaucoma, particularly if the small lens is displaced.
Topics: Anterior Chamber; Child; Family; Female; Humans; Lens, Crystalline; Medical Records; Myopia; Visual Acuity
PubMed: 12366350
DOI: 10.1111/j.1444-0938.2002.tb03085.x -
European Radiology Nov 2022As described recently, intravenously injected gadolinium-based contrast agent (GBCA) penetrates into the anterior eye chamber (AC) and is drained from the retina to the...
OBJECTIVES
As described recently, intravenously injected gadolinium-based contrast agent (GBCA) penetrates into the anterior eye chamber (AC) and is drained from the retina to the distal optic nerve (ON) along perivascular spaces, which serves retinal homeostasis and was termed the orbital glymphatic system (GS). Independently, AC enhancement predicted ON infiltration, a major risk factor for advanced retinoblastoma (RB), in a small RB patient cohort. We aimed to review the supposed imaging biomarker for ON infiltration in a large RB cohort and with respect to the recently described orbital GS.
METHODS
This IRB-approved retrospective single-center study encompassed 539 orbital MRIs performed with an orbital coil and with the children under general anesthesia. Differences of signal intensity ratios (∆SIRs) of the AC to the lens were determined between non-contrast and GBCA-enhanced T1-weighted images and were correlated with histopathologic presence of ON infiltration.
RESULTS
∆SIR of the RB eye was an independent, significant predictor for ON invasion in multivariate analysis with adjustment for tumor size (p < 0.05) and increased with infiltration level.
CONCLUSIONS
GBCA enhancement of the AC predicts ON infiltration. This might be caused by impairment of the orbital glymphatic system, which is supposed to clear toxic metabolites from the retina to the postlaminar ON. In RB with ON infiltration, this efflux path is likely to be inhibited, which is supposed to result in disturbed retinal homeostasis, release of vascular endothelial growth factor, and iris neovascularization, which increases penetration of GBCA into the AC.
KEY POINTS
• Infiltration of the optic nerve can be predicted by anterior chamber enhancement after intravenous MRI contrast agent administration. • Increased anterior chamber enhancement in retinoblastoma with optic nerve infiltration might result from dysfunction of the orbital glymphatic system with disturbance of retinal homeostasis and consecutive iris neovascularization.
Topics: Child; Humans; Anterior Chamber; Contrast Media; Magnetic Resonance Imaging; Neoplasm Invasiveness; Optic Nerve; Retinal Neoplasms; Retinoblastoma; Retrospective Studies; Vascular Endothelial Growth Factor A
PubMed: 35524782
DOI: 10.1007/s00330-022-08778-4 -
American Journal of Ophthalmology Jun 2024To investigate the correlation between the opening and closing states of anterior chamber angle (ACA) and the density of limbal epithelial basal cells (LEBCs) in... (Observational Study)
Observational Study
PURPOSE
To investigate the correlation between the opening and closing states of anterior chamber angle (ACA) and the density of limbal epithelial basal cells (LEBCs) in subjects with primary angle-closure glaucoma (PACG).
DESIGN
Cross-sectional observational study.
METHODS
A total of 54 eyes of 29 patients diagnosed with PACG were included in the study. Fifty-four eyes from normal subjects were included as control. Automatic evaluation system for ultrasound biomicroscopy images of anterior chamber angle was used to assist ophthalmologists in identifying the opening or closing state of ACA, and the in vivo confocal microscopy (IVCM) was used to evaluate the density of LEBCs in different directions.
RESULTS
(1) The average density of LEBCs in the superior, inferior, nasal, and temporal limbus of the eyes in the PACG group was lower than that in the control group, and this pattern did not align with the density distribution observed in the control group. (2) In the early, moderate and advanced PACG, the density of LEBCs corresponding to the closed angle was lower than that in the control group (P < .05). Compared with the density of LEBCs corresponding to the closed angle and the open angle, the closed angle of PACG in the early, moderate and advanced stages was less than that in the open angle (P < .05 in the early and moderate stages; advanced stage P > .05). (3) The basal cell density was processed by dimensionless analysis. In the data calculated by averaging and minimizing, both closed angle dimensionless values were smaller than the open angle (P < .05). (4) Comparative analysis was conducted among the normal, open-angle, and closed-angle conditions in the superior, inferior, nasal, and temporal limbus. In the early stage of PACG, significant differences were observed in 4 limbal regions (P < .05), while in the moderate PACG stage, this difference was noted in 3 limbal regions (P < .05). In advanced PACG, 2 limbal regions exhibited significant differences (P < .05). These findings suggest that during the early PACG stage, angle closure is the predominant influencing factor on LEBCs density, while in the advanced stage, the decrease in density is attributed to a combination of angle closure and the natural progression of the disease.
CONCLUSIONS
There is a significant correlation between anterior chamber angle status and LEBCs. Advanced PACG and angle closure should be highly suspected of the occurrence of limbal stem cell deficiency (LSCD).
Topics: Humans; Glaucoma, Angle-Closure; Cross-Sectional Studies; Limbus Corneae; Male; Female; Middle Aged; Anterior Chamber; Microscopy, Acoustic; Cell Count; Microscopy, Confocal; Aged; Stem Cells; Intraocular Pressure; Gonioscopy; Limbal Stem Cell Deficiency
PubMed: 38360335
DOI: 10.1016/j.ajo.2024.01.034 -
Ocular Immunology and Inflammation Feb 2022The objective grading of anterior chamber inflammation (ACI) has remained a challenge in the field of uveitis. While the grading criteria produced by the Standardization...
The objective grading of anterior chamber inflammation (ACI) has remained a challenge in the field of uveitis. While the grading criteria produced by the Standardization of Uveitis Nomenclature (SUN) International Workshop have been widely adopted, limitations exist including interobserver variability and grading confined to discrete categories rather than a continuous measurement. Since the earliest iterations of optical coherence tomography (OCT), ACI has been assessed using anterior segment OCT and shown to correlate with slit-lamp findings. However, widespread use of this approach has not been adopted. Barriers to standardization include variability in OCT devices across clinical settings, lack of standardization of image acquisition protocols, varying quantification methods, and the difficulty of distinguishing inflammatory cells from other cell types. Modern OCT devices and techniques in artificial intelligence show promise in expanding the clinical applicability of anterior segment OCT for the grading of ACI.
Topics: Anterior Chamber; Artificial Intelligence; Humans; Inflammation; Tomography, Optical Coherence; Uveitis; Uveitis, Anterior
PubMed: 35442873
DOI: 10.1080/09273948.2022.2028289 -
The British Journal of Ophthalmology Jan 1972
Topics: Anterior Chamber; Ciliary Body; Drainage; Follow-Up Studies; Glaucoma; Humans; Methods; Sclera
PubMed: 5058715
DOI: 10.1136/bjo.56.1.37 -
PloS One 2021To determine the relationship between the external limbal location, represented by white-to-white (WTW) distance, and the actual angle location, represented by...
PURPOSE
To determine the relationship between the external limbal location, represented by white-to-white (WTW) distance, and the actual angle location, represented by spur-to-spur (STS) and angle-to-angle (ATA) distances.
METHODS
166 eyes from 166 participants were imaged using CASIA2 anterior chamber optical coherence tomography (AS-OCT) and LenStar LS 900 optical biometer. The horizontal ATA and STS were measured using the swept-source Fourier-domain AS-OCT (CASIA2). The horizontal WTW was automatically measured using LenStar. The displacement lengths (DL) between WTW-STS and WTW-ATA were calculated. Bland-Altman plots and intraclass correlation were performed.
RESULTS
The study showed that WTW has a positive correlation with STS (ICC = 0.82, p<0.001) and ATA (ICC = 0.82, p<0.001). The Bland-Altman analysis demonstrated that the mean difference of WTW-STS is 0.10 mm (95% CI 0.06 to 0.14 mm) with limits of agreement of -0.42 to 0.63 mm between WTW and STS, and the mean difference of WTW-ATA is 0.10 mm (95% CI 0.06 to 0.15 mm) with limits of agreement of -0.48 to 0.64 mm between WTW and ATA. Linear regression with adjustment showed that a WTW value greater than 12.07 mm is associated with a greater DL (WTW-STS DL ß 0.18, p = 0.003; WTW-ATA DL ß 0.14, p = 0.03).
CONCLUSIONS
Greater WTW was significantly associated with higher displacement of WTW from the two distances representing anterior chamber width. External limbal location may not accurately represent the actual angle location in eyes with larger WTW.
Topics: Adult; Aged; Aged, 80 and over; Anterior Chamber; Biometry; Cornea; Eye; Female; Humans; Lasers; Lens, Crystalline; Male; Middle Aged; Tomography, Optical Coherence; Vision, Ocular
PubMed: 34015039
DOI: 10.1371/journal.pone.0251990 -
BMC Ophthalmology Sep 2021The purpose of this study was to implement and evaluate a deep learning (DL) approach for automatically detecting shallow anterior chamber depth (ACD) from...
BACKGROUND
The purpose of this study was to implement and evaluate a deep learning (DL) approach for automatically detecting shallow anterior chamber depth (ACD) from two-dimensional (2D) overview anterior segment photographs.
METHODS
We trained a DL model using a dataset of anterior segment photographs collected from Shanghai Aier Eye Hospital from June 2018 to December 2019. A Pentacam HR system was used to capture a 2D overview eye image and measure the ACD. Shallow ACD was defined as ACD less than 2.4 mm. The DL model was evaluated by a five-fold cross-validation test in a hold-out testing dataset. We also evaluated the DL model by testing it against two glaucoma specialists. The performance of the DL model was calculated by metrics, including accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC).
RESULTS
A total of 3753 photographs (1720 shallow AC and 2033 deep AC images) were assigned to the training dataset, and 1302 photographs (509 shallow AC and 793 deep AC images) were held out for two internal testing datasets. In detecting shallow ACD in the internal hold-out testing dataset, the DL model achieved an AUC of 0.86 (95% CI, 0.83-0.90) with 80% sensitivity and 79% specificity. In the same testing dataset, the DL model also achieved better performance than the two glaucoma specialists (accuracy of 80% vs. accuracy of 74 and 69%).
CONCLUSIONS
We proposed a high-performing DL model to automatically detect shallow ACD from overview anterior segment photographs. Our DL model has potential applications in detecting and monitoring shallow ACD in the real world.
TRIAL REGISTRATION
http://clinicaltrials.gov , NCT04340635 , retrospectively registered on 29 March 2020.
Topics: Anterior Chamber; China; Deep Learning; Glaucoma; Humans; ROC Curve
PubMed: 34551738
DOI: 10.1186/s12886-021-02104-0 -
Acta Ophthalmologica Dec 2022To determine the utility of Split-Window optical coherence tomography OCT (SW-OCT) biometry in measuring ocular axial dimensions as well as imaging the intraocular lens...
PURPOSE
To determine the utility of Split-Window optical coherence tomography OCT (SW-OCT) biometry in measuring ocular axial dimensions as well as imaging the intraocular lens (IOL) and posterior capsule in pseudophakic eyes.
METHODS
Sixty-nine pseudophakic eyes of 69 subjects were enrolled in the study. The results of SW-OCT biometry implemented in the SD OCT device for posterior and anterior segment imaging (REVO NX, Optopol Technology) were compared with those obtained with the SS-OCT-based biometer IOLMaster 700 (Carl Zeiss Meditec). Differences in measurement values between the two biometers were determined using the paired t-test. Agreement was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots.
RESULTS
The correlation between measurements obtained with SW-OCT and SS-OCT was very high (ICC for: axial length (AL) = 1.000; anterior chamber depth (ACD) = 0.997; IOL thickness (IOL LT) = 0.997; central corneal thickness (CCT) = 0.987). The mean AL measurement difference was 0.003 ± 0.021 mm (the 95% LoA ranged from -0.04 to 0.05); the mean ACD difference was -0.009 ± 0.025 mm (95% LoA, -0.06 to 0.04); mean LT difference was 0.001 ± 0.021 mm (95% LoA, -0.04 to 0.04); and mean CCT difference was 1.4 ± 5.4 μm (95% LoA, -9 to 12).
CONCLUSION
The study shows small, non-significant differences between the biometric measurements obtained with REVO NX SW-OCT and IOLMaster 700 SS-OCT in pseudophakic eyes. However, SW-OCT offered significantly lower ACD and LT measurement failure rates. With high-resolution imaging, SW-OCT enables accurate assessment of IOL position relative to the posterior capsule and visualization of capsular fibrosis.
Topics: Humans; Axial Length, Eye; Tomography, Optical Coherence; Reproducibility of Results; Biometry; Lenses, Intraocular; Anterior Chamber; Interferometry; Cornea
PubMed: 35670319
DOI: 10.1111/aos.15198 -
Clinical & Experimental Optometry Jul 2006Improvements in imaging chips and computer processing power have brought major advances in imaging of the anterior eye. Digitally captured images can be visualised... (Review)
Review
Improvements in imaging chips and computer processing power have brought major advances in imaging of the anterior eye. Digitally captured images can be visualised immediately and can be stored and retrieved easily. Anterior ocular imaging techniques using slitlamp biomicroscopy, corneal topography, confocal microscopy, optical coherence tomography (OCT), ultrasonic biomicroscopy, computerised tomography (CT) and magnetic resonance imaging (MRI) are reviewed. Conventional photographic imaging can be used to quantify corneal topography, corneal thickness and transparency, anterior chamber depth and lateral angle and crystalline lens position, curvature, thickness and transparency. Additionally, the effects of tumours, foreign bodies and trauma can be localised, the corneal layers can be examined and the tear film thickness assessed.
Topics: Anterior Chamber; Diagnostic Imaging; Equipment Design; Humans
PubMed: 16776728
DOI: 10.1111/j.1444-0938.2006.00065.x -
The Journal of International Medical... Dec 2019To investigate the clinical indications of ultrasound biomicroscopy (UBM) and anterior segment optical coherence tomography (AS-OCT) in eyes with inflammatory glaucoma. (Observational Study)
Observational Study
OBJECTIVE
To investigate the clinical indications of ultrasound biomicroscopy (UBM) and anterior segment optical coherence tomography (AS-OCT) in eyes with inflammatory glaucoma.
METHODS
Sixteen patients (16 eyes) with inflammatory glaucoma were analysed retrospectively. All of the subjects underwent UBM and AS-OCT scans, measuring the following parameters: central corneal thickness (CCT), central anterior chamber depth (ACD), angle-opening distance (AOD500), and trabecular-iris angle (TIA500) in four quadrants.
RESULTS
Both the UBM and AS-OCT generated detailed, high-resolution images of the anterior segments of the eyes with inflammatory glaucoma. Moreover, the UBM and AS-OCT exhibited statistically similar measurement results for all of the indices. A Bland–Altman analysis showed a high level of agreement between the two imaging techniques. Additionally, the UBM was able to visualize the ciliary body and pars plana, while the cells and the flare in the anterior chamber appeared more pronounced in the UBM images.
CONCLUSIONS
Both the UBM and AS-OCT are useful tools for anterior segment imaging and taking measurements needed for evaluating inflammatory glaucoma. The AS-OCT has the advantages of being noninvasive and fast, whereas the UBM is presently unparalleled in the visualization of the ciliary body and pars plana.
Topics: Adult; Anterior Chamber; Female; Glaucoma; Humans; Inflammation; Male; Microscopy, Acoustic; Middle Aged; Tomography, Optical Coherence; Uveitis; Young Adult
PubMed: 31594445
DOI: 10.1177/0300060519867808