76 research outputs found
Advances in Glaucoma Treatment
No full textGlaucoma is an optic neuropathy that is characterized by the death of retinal ganglion cells and leads to the progressive loss of vision. This Reprint presents the new frontiers in "Glaucoma Treatment". It includes pharmaceutical and surgical treatments
Impact of corneal cross-linking combined with photorefractive keratectomy on blurring strength
No full textGeorgios Labiris,1,2 Haris Sideroudi,2 Dimitris Angelonias,2 Kimonas Georgantzoglou,2 Vassilios P Kozobolis1,21Department of Ophthalmology, University Hospital of Alexandroupolis, 2Eye Institute of Thrace, Alexandroupolis, GreecePurpose: The aim of this study was to evaluate the impact of corneal cross-linking combined with photorefractive keratectomy (PRK) on blurring strength.Methods: A total of 63 patients with keratoconus were recruited for this study, and two study groups were formed according to the therapeutic intervention: corneal collagen cross-linking (CxL) group (33 patients) received corneal cross-linking according to the Dresden protocol, while the rest additionally received topography-guided photorefractive keratectomy (tCxL). The impact of surgical procedure on blurring strength was assessed by power vector analysis. Potential association between blurring strength and vision-specific quality of life was assessed using the National Eye Institute Visual Function Questionnaire (NEI-VFQ) 25 instrument.Results: Blurring strength presented excellent correlation with NEI-VFQ scores both preoperatively and postoperatively (all P<0.01). Both groups demonstrated nonsignificant changes in best-corrected visual acuity; however, only the tCxL group had significant reduction in blurring strength (13.48+10.86 [preoperative], 4.26+7.99 [postoperative], P=0.042).Conclusion: Only the combined treatment (tCxL) resulted in significant reduction in blurring strength. Moreover, the excellent correlation of blurring strength with NEI-VFQ scores indicates its reliability as an index of self-reported quality of life in keratoconus, since it seems to address the nonsignificant changes in best-corrected visual acuity following CxL treatments that are conceived as subjective improvement by the patient.Keywords: keratoconus, cornea crosslinking, blurring strength, tCx
Impact of light conditions on reading ability following multifocal pseudophakic corrections
No full textGeorgios Labiris, Panagiota Ntonti, Eirini-Kanella Panagiotopoulou, Aristeidis Konstantinidis, Maria Gkika, Doukas Dardabounis, Irfan Perente, Haris Sideroudi Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece Purpose: To examine the impact of light intensity and temperature on reading performance following bilateral pseudophakic multifocal presbyopic correction.Patients and methods: This is a prospective clinic-based trial conducted at the Department of Ophthalmology in the University Hospital of Alexandroupolis, Greece. Three groups of patients were formed (G1: patients with bilateral bifocal implantation, G2: patients with bilateral trifocal implantation, and control group: patients with bilateral pseudophakic monofocal implantation). Reading ability was quantified with the Greek version of MNREAD chart with minimal reading speed at 80 words/min for the following light intensities (25, 50, and 75 Foot-Candles [FC]) and temperatures (3,000, 4,000, and 6,000 K). Preferred light conditions for reading were assessed, as well. ClinicalTrials.gov Identifier: NCT03226561.Results: Control group demonstrated significantly lower reading ability at all light combinations with maximal ability at 75 FC and 6,000 K (0.58±0.18 logMAR). Bifocal group presented a light-dependent reading ability that ranged from 0.45±0.08 logMAR (25 FC and 3,000 K) to 0.40±0.11 logMAR (75 FC and 4,000 or 6,000 K). Trifocal participants presented the best reading ability that was light intensity-independent; however, their performance was reduced at 6,000 K. G1 and G2 preferred primarily intermediate light temperature, while control participants preferred cold light temperature.Conclusion: Multifocal pseudophakic corrections improve reading ability; however, they present variable efficacy according to the light conditions. Keywords: presbyopia, light intensity, Kelvin, Foot-Candles, trifocal, bifoca
The Eye Institute of Thrace glaucoma progression diagram (EIT-GPD): incorporating the relationship between visual ability and visual fields
No full textStudy of ocular markers for assessing drowsiness in patients with obstructive sleep apnea syndrome
No full textΒιβλιογραφία: σ. 67-71Εισαγωγή: Η υπνηλία αποτελεί μια πολύπλοκη κατάσταση και συνδέεται με αυξημένο κίνδυνο ατυχημάτων, μειωμένη παραγωγικότητα και υποβάθμιση της ποιότητας ζωής. Η εκτίμησή της γίνεται είτε μέσω υποκειμενικών είτε μέσω αντικειμενικών μεθόδων.
Σκοπός της παρούσας μελέτης ήταν η ανάλυση των βλεφαρισμών ως αντικειμενικών δεικτών υπνηλίας σε ασθενείς με Σύνδρομο Αποφρακτικής Υπνικής Άπνοιας (ΣΑΑΥ). Συγκεκριμένα, η μελέτη είχε ως στόχο να διερευνήσει τη σχέση μεταξύ της ημερήσιας υπνηλίας και των βλεφαρισμών καθώς επίσης και να συμβάλει στην ανάπτυξη νέων αντικειμενικών βιοδεικτών για την αξιολόγηση της υπνηλίας, πέρα από τις κλασικές υποκειμενικές μεθόδους. Ασθενείς-Μέθοδοι: Μελετήθηκαν 41 άτομα (14 γυναίκες/27 άνδρες),με Σύνδρομο Αποφρακτικής Υπνικής Άπνοιας, (οι οποίοι υπεβλήθησαν σε πολυυπνογραφία λόγω συμπτωμάτων ενδεικτικών διαταραχών της αναπνοής στον ύπνο) και στη συνέχεια μετρήθηκαν οι βλεφαρισμοί ανά λεπτό με τη βοήθεια κάμερας τοποθετημένης μπροστά από τον ασθενή σε προκαθορισμένη απόσταση και χρήση ειδικού αλγορίθμου για την αυτόματη ψηφιακή ανάλυση των βίντεο που καταγράφουν τις οφθαλμικές κινήσεις. Αποτελέσματα: Βρέθηκε μια στατιστικά σημαντική θετική συσχέτιση μεταξύ της κλίμακας Epworth και του αριθμού των μέγιστων βλεφαρισμών ανά λεπτό (r = 0.319, p = 0.042), χωρίς ωστόσο σημαντική διαφορά μεταξύ ομάδων υπνηλίας, καθώς η μέση τιμή των μέγιστων βλεφαρισμών διαφέρει σε μικρό βαθμό μεταξύ των διαφορετικών επιπέδων υπνηλίας (χαμηλή, μέτρια, υψηλή). Συμπεράσματα: Η παρούσα μελέτη δεν κατέδειξε ισχυρή σχέση μεταξύ των βλεφαρισμών και της υπνηλίας, με τα αποτελέσματα να υποδεικνύουν ότι η συχνότητα των βλεφαρισμών θα μπορούσε να αποτελεί έναν πιθανό βιοδείκτης κόπωσης ή υπνηλίας ο οποίος χρήζει περαιτέρω διερεύνησης.Introduction: Sleepiness is a complex condition associated with an increased risk of accidents, reduced productivity, and a decline in quality of life. Its assessment can be performed using either subjective or objective methods. The aim of the present study was to analyze blink parameters as objective indicators of sleepiness in patients with Obstructive Sleep Apnea Syndrome (OSAS). Specifically, the study aimed to investigate the relationship between daytime sleepiness and blink rate and to contribute to the development of novel objective biomarkers for sleepiness assessment beyond traditional subjective methods. Patients and Methods: A total of 41 individuals (14 females/27 males) with Obstructive Sleep Apnea Syndrome, who underwent polysomnography due to symptoms indicative of sleep-disordered breathing, were studied. Blink rate per minute was subsequently measured using a camera positioned at a predetermined distance in front of the patient, combined with a specialized algorithm for the automated digital analysis of video recordings capturing eye movements. Results: A statistically significant positive correlation was found between the Epworth Sleepiness Scale and the maximum blink rate per minute (r = 0.319, p = 0.042). However, no significant difference was observed between sleepiness groups, as the mean maximum blink rate differed only slightly across different levels of sleepiness (low, moderate, high). Conclusions: This study did not establish a strong association between blink rate and sleepiness. The findings suggest that blink frequency could serve as a potential biomarker for fatigue or sleepiness, which warrants further investigation.71 σ
Corneal collagen cross-linking using riboflavin and ultraviolet-A irradiation: a review of clinical and experimental studies
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Blink Detection Using 3D Convolutional Neural Architectures and Analysis of Accumulated Frame Predictions
No full textBlink detection is considered a useful indicator both for clinical conditions and drowsiness state. In this work, we propose and compare deep learning architectures for the task of detecting blinks in video frame sequences. The first step is the training and application of an eye detector that extracts the eye regions from each video frame. The cropped eye regions are organized as three-dimensional (3D) input with the third dimension spanning time of 300 ms. Two different 3D convolutional neural networks are utilized (a simple 3D CNN and 3D ResNet), as well as a 3D autoencoder combined with a classifier coupled to the latent space. Finally, we propose the usage of a frame prediction accumulator combined with morphological processing and watershed segmentation to detect blinks and determine their start and stop frame in previously unseen videos. The proposed framework was trained on ten (9) different participants and tested on five (8) different ones, with a total of 162,400 frames and 1172 blinks for each eye. The start and end frame of each blink in the dataset has been annotate by specialized ophthalmologist. Quantitative comparison with state-of-the-art blink detection methodologies provide favorable results for the proposed neural architectures coupled with the prediction accumulator, with the 3D ResNet being the best as well as the fastest performer
Corneal Collagen Cross-Linking Using Riboflavin and Ultraviolet-A Irradiation in Keratitis Treatment
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