Η συμβολή της swap περιμετρίας στην πρώιμη διάγνωση του χρόνιου γλαυκώματος

2013 ◽  
Author(s):  
Ιωάννης Χαββάς
Keyword(s):  
Humphrey Field Analyzer ◽  
Pattern Deviation ◽  
Deviation Plot

Σκοπός: Η σύγκριση των δυο περιμετριών, SWAP και SAP την στιγμή της μετατροπής στο γλαύκωμα. Ασθενείς και Μέθοδοι: Πρόκειται για μια προοπτική μελέτη ασθενών με οφθαλμική υπερτονία. Διακόσιοι ογδόντα δυο ασθενείς με οφθαλμική υπερτονία συμπεριελήφθησαν διαδοχικά και εξετάστηκαν με SAP και SWAP κάθε χρόνο για 5 χρόνια ή μέχρι την μετατροπή σε γλαύκωμα. Τόσο η SAP όσο και η SWAP πραγματοποιήθηκαν με το Humphrey Field Analyzer II χρησιμοποιώντας το 24-2 full threshold. Η ανωμαλία τόσο για την SAP όσο και για την SWAP καθορίστηκε από το διάγραμμα της pattern deviation plot και ορίστηκε ως: α) ένα σημείο κάτω από το 0,5% επίπεδο στατιστικής σημαντικότητας ή β) ένα σύμπλεγμα 2 ή περισσοτέρων σημείων κάτω από το 1% ή γ) ένα σύμπλεγμα από 3 ή περισσότερα σημεία κάτω από 5%. Τα παθολογικά τεστ έπρεπε να επαληθευτούν μέσα σε ένα χρόνο για να θεωρηθούν ως μετατροπή. Αποτελέσματα: Από τους 282 που συμπεριελήφθησαν αρχικά, 32 ασθενείς εξαιρέθηκαν. Από τους 250 που παρέμειναν στην μελέτη, ένα σύνολο από 38 ασθενείς μετατράπηκαν κατά την διάρκεια της παρακολούθησης. 36,8% των μετατροπών ανιχνεύτηκαν νωρίτερα με την SWAP, 29% ταυτόχρονα και 34,2% δεν ανιχνεύτηκαν με την SWAP κατά την διάρκεια της περιόδου παρακολούθησης. 2,4% των ασθενών παρουσίασαν ελλείμματα στην SWAP που δεν κατέληξαν σε μετατροπή κατά την διάρκεια της παρακολούθησης. Συζήτηση: Υπήρξαν ασθενείς με πρώιμη, ταυτόχρονη η καθόλου μετατροπή στη SWAP χρησιμοποιώντας την SAP για το κριτήριο αναφοράς. Καθώς η κάθε μέθοδος ανιχνεύει το γλαύκωμα σε ένα υποσύνολο ασθενών και αυτά τα υποσύνολα επικαλύπτονται μερικώς ίσως να ήταν δόκιμο να γίνεται έλεγχος τόσο με την SWAP όσο και με την SAP με επανάληψη όταν είναι εμφανής η απώλεια οπτικών πεδίων.

Outer retinal layer thickness in patients with glaucoma with horizontal hemifield visual field defects

2018 ◽  
Vol 103 (9) ◽  
pp. 1217-1222 ◽  
Author(s):  
Jayme R Vianna ◽  
Ziad Butty ◽  
Lucas A Torres ◽  
Glen P Sharpe ◽  
Donna M Hutchison ◽  
...  
Keyword(s):  
Visual Field ◽  
Layer Thickness ◽  
Cross Sectional Study ◽  
Mirror Image ◽  
Visual Field Defects ◽  
Mean Deviation ◽  
Retinal Layer ◽  
Cross Sectional ◽  
Pattern Deviation ◽  
Deviation Plot

Background/AimsTo determine the effect of glaucoma on outer retinal layer thickness in eyes with horizontal hemifield visual field (VF) defects.MethodsWe conducted a cross-sectional study in glaucomatous eyes with repeatable (in three or examinations) horizontal hemifield VF (programme 24–2) defect defined as: all five nasal VF locations immediately either above or below the horizontal midline abnormal in the pattern deviation plot with p<0.5%; no mirror-image adjacent 5 VF locations abnormal in the pattern deviation plot and no non-edge VF locations in the non-affected hemifield abnormal in the pattern deviation plot with p<1%. We used optical coherence tomography to measure thickness of each retinal layer in the temporal macula (12° horizontally and 24° vertically) and computed the absolute (µm) and relative (%) intraindividual asymmetry between the perimetrically normal and abnormal hemimacula.ResultsWe included 10 eyes of 8 patients with median age of 67 years and median VF mean deviation of −8.85 dB. The nerve fibre, ganglion cell and inner plexiform layers were significantly thinner in the perimetrically abnormal hemimacula (median asymmetry of –6.4, –11.5 and −3.8 µm, (corresponding to –27.7, –40.5 and −15.7 %), respectively, all p≤0.01). The inner nuclear layer was slightly thicker in the perimetrically abnormal hemimacula (median asymmetry of 1.3 µm (5.0 %), p=0.01). The outer plexiform, outer nuclear and photoreceptor layers asymmetry values were negligible.ConclusionOur study showed no evidence that glaucoma has an effect on the outer retinal layer thickness. In contrast, a large impact was observed in inner layer thickness.

Multi-center comparison of the Toronto Portable Perimeter to the Humphrey Field Analyzer: A Pilot Study

2021 ◽  
Author(s):  
Yusuf Ahmed ◽  
Austin Pereira ◽  
Sylvie Bowden ◽  
Runjie B. Shi ◽  
Yan Li ◽  
...  
Keyword(s):  
Pilot Study ◽  
Humphrey Field Analyzer

Investigating the clinical usefulness of definitions of progression with 10-2 visual field

2021 ◽  
pp. bjophthalmol-2020-318188
Author(s):  
Shotaro Asano ◽  
Hiroshi Murata ◽  
Yuri Fujino ◽  
Takehiro Yamashita ◽  
Atsuya Miki ◽  
...  
Keyword(s):  
Visual Field ◽  
False Positive ◽  
False Positive Rate ◽  
Clinical Validity ◽  
Data Set ◽  
Humphrey Field Analyzer ◽  
Positive Rate ◽  
Using Data ◽  
Sensitivity Specificity ◽  
Higher Sensitivity

Background/AimTo investigate the clinical validity of the Guided Progression Analysis definition (GPAD) and cluster-based definition (CBD) with the Humphrey Field Analyzer 10-2 test in diagnosing glaucomatous visual field (VF) progression, and to introduce a novel definition with optimised specificity by combining the ‘any-location’ and ‘cluster-based’ approaches (hybrid definition).Methods64 400 stable glaucomatous VFs were simulated from 664 pairs of 10-2 tests (10 sets × 10 VF series × 664 eyes; data set 1). Using these simulated VFs, the specificity to detect progression and the effects of changing the parameters (number of test locations or consecutive VF tests, and percentile cut-off values) were investigated. The hybrid definition was designed as the combination where the specificity was closest to 95.0%. Subsequently, another 5000 actual glaucomatous 10-2 tests from 500 eyes (10 VFs each) were collected (data set 2), and their accuracy (sensitivity, specificity and false positive rate) and the time needed to detect VF progression were evaluated.ResultsThe specificity values calculated using data set 1 with GPAD and CBD were 99.6% and 99.8%. Using data set 2, the hybrid definition had a higher sensitivity than GPAD and CBD, without detriment to the specificity or false positive rate. The hybrid definition also detected progression significantly earlier than GPAD and CBD (at 3.1 years vs 4.2 years and 4.1 years, respectively).ConclusionsGPAD and CBD had specificities of 99.6% and 99.8%, respectively. A novel hybrid definition (with a specificity of 95.5%) had higher sensitivity and enabled earlier detection of progression.

scholarly journals Normal correspondence of tectal maps for saccadic eye movements in strabismus

2016 ◽  
Vol 116 (6) ◽  
pp. 2541-2549 ◽  
Author(s):  
John R. Economides ◽  
Daniel L. Adams ◽  
Jonathan C. Horton
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Saccadic Eye Movements ◽  
Systematic Change ◽  
Free Viewing ◽  
Pattern Deviation ◽  
Ocular Deviation ◽  
The Right ◽  
Stem Structure

The superior colliculus is a major brain stem structure for the production of saccadic eye movements. Electrical stimulation at any given point in the motor map generates saccades of defined amplitude and direction. It is unknown how this saccade map is affected by strabismus. Three macaques were raised with exotropia, an outwards ocular deviation, by detaching the medial rectus tendon in each eye at age 1 mo. The animals were able to make saccades to targets with either eye and appeared to alternate fixation freely. To probe the organization of the superior colliculus, microstimulation was applied at multiple sites, with the animals either free-viewing or fixating a target. On average, microstimulation drove nearly conjugate saccades, similar in both amplitude and direction but separated by the ocular deviation. Two monkeys showed a pattern deviation, characterized by a systematic change in the relative position of the two eyes with certain changes in gaze angle. These animals' saccades were slightly different for the right eye and left eye in their amplitude or direction. The differences were consistent with the animals' underlying pattern deviation, measured during static fixation and smooth pursuit. The tectal map for saccade generation appears to be normal in strabismus, but saccades may be affected by changes in the strabismic deviation that occur with different gaze angles.

Source Camera Identification Based on Sensor Readout Noise

2010 ◽  
Vol 2 (3) ◽  
pp. 28-42 ◽  
Author(s):  
H. R. Chennamma ◽  
Lalitha Rangarajan
Keyword(s):  
Computer Software ◽  
Sensor Data ◽  
Processing Parameter ◽  
Source Camera Identification ◽  
Camera Identification ◽  
Novel Approach ◽  
Deviation Plot ◽  
Readout Noise ◽  
The One ◽  
Imaging Sensor

A digitally developed image is a viewable image (TIFF/JPG) produced by a camera’s sensor data (raw image) using computer software tools. Such images might use different colour space, demosaicing algorithms or by different post processing parameter settings which are not the one coded in the source camera. In this regard, the most reliable method of source camera identification is linking the given image with the sensor of camera. In this paper, the authors propose a novel approach for camera identification based on sensor’s readout noise. Readout noise is an important intrinsic characteristic of a digital imaging sensor (CCD or CMOS) and it cannot be removed. This paper quantitatively measures readout noise of the sensor from an image using the mean-standard deviation plot, while in order to evaluate the performance of the proposed approach, the authors tested against the images captured at two different exposure levels. Results show datasets containing 1200 images acquired from six different cameras of three different brands. The success of proposed method is corroborated through experiments.

Short-Wavelength Automated Perimetry and Neuroretinal Rim Area

2000 ◽  
Vol 10 (2) ◽  
pp. 116-120 ◽  
Author(s):  
J.M. Larrosa ◽  
V. Polo ◽  
L. Pablo ◽  
I. Pinilla ◽  
F.J. Fernandez ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Visual Field ◽  
Short Wavelength ◽  
Selection Criteria ◽  
Visual Fields ◽  
Automated Perimetry ◽  
Neuroretinal Rim ◽  
Humphrey Field Analyzer ◽  
Neuroretinal Rim Area

Purpose To determine the correlation between neuroretinal rim area and functional losses detected by short-wavelength automated perimetry (SWAP) in a population of patients with suspected glaucoma. Methods Forty-two eyes of 42 ocular hypertensive subjects who met the selection criteria (intraocular pressure greater than 21 mm of Hg and normal conventional visual fields) were studied. A planimetric optic nerve head study was performed, determining the total and sectorized neuroretinal rim areas. SWAP was also done, with a modified Humphrey field analyzer. Results There were no significant correlations between the neuroretinal rim areas and the global perimetric parameters. However, the correlations between the inferotemporal neuroretinal rim area and some superonasal visual field regions (areas 3 and 4) were significant. Conclusions There is a relation in the topography of some visual field areas assessed by SWAP and the inferotemporal neuroretinal rim area, which may play a role in the diagnosis and follow-up of suspected glaucoma.

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