Blood Supply of the Optic Nerve Head and its Role in Optic Atrophy, Glaucoma and Oedema of the Optic Disc

2015 ◽  
pp. 510-530 ◽  
Author(s):  
S. S. Hayreh
2020 ◽  
Vol 10 (11) ◽  
pp. 3833 ◽  
Author(s):  
Haidar Almubarak ◽  
Yakoub Bazi ◽  
Naif Alajlan

In this paper, we propose a method for localizing the optic nerve head and segmenting the optic disc/cup in retinal fundus images. The approach is based on a simple two-stage Mask-RCNN compared to sophisticated methods that represent the state-of-the-art in the literature. In the first stage, we detect and crop around the optic nerve head then feed the cropped image as input for the second stage. The second stage network is trained using a weighted loss to produce the final segmentation. To further improve the detection in the first stage, we propose a new fine-tuning strategy by combining the cropping output of the first stage with the original training image to train a new detection network using different scales for the region proposal network anchors. We evaluate the method on Retinal Fundus Images for Glaucoma Analysis (REFUGE), Magrabi, and MESSIDOR datasets. We used the REFUGE training subset to train the models in the proposed method. Our method achieved 0.0430 mean absolute error in the vertical cup-to-disc ratio (MAE vCDR) on the REFUGE test set compared to 0.0414 obtained using complex and multiple ensemble networks methods. The models trained with the proposed method transfer well to datasets outside REFUGE, achieving a MAE vCDR of 0.0785 and 0.077 on MESSIDOR and Magrabi datasets, respectively, without being retrained. In terms of detection accuracy, the proposed new fine-tuning strategy improved the detection rate from 96.7% to 98.04% on MESSIDOR and from 93.6% to 100% on Magrabi datasets compared to the reported detection rates in the literature.


1996 ◽  
Vol 210 (5) ◽  
pp. 285-295 ◽  
Author(s):  
Sohan Singh Hayreh

Ophthalmology ◽  
2010 ◽  
Vol 117 (8) ◽  
pp. 1547-1553 ◽  
Author(s):  
Piero Barboni ◽  
Michele Carbonelli ◽  
Giacomo Savini ◽  
Beatrice Foscarini ◽  
Vincenzo Parisi ◽  
...  

2019 ◽  
Vol 7 ◽  
pp. 2050313X1986947
Author(s):  
Ramesh Venkatesh ◽  
Prachi Gurav

A 61-year-old elderly male, hypertensive patient presented to the retina clinic with sudden drop in vision in the left eye for 6 days. His best-corrected visual acuity at presentation was counting fingers close to face. Fundus examination of the left eye revealed the presence of subretinal and preretinal haemorrhage at the macula along with hypertensive retinopathy changes in both eyes. Fluorescein angiography was done, which showed a retinal artery macroaneurysm at the optic nerve head. Optical coherence tomogram through the optic nerve head also confirmed the presence of retinal artery macroaneurysm. The patient was treated with injection of 0.4 cc of 100% C3F8 to displace the blood off the macula. At final follow-up visit at 2 months post treatment, his vision improved to 6/12, N8. Fundus examination showed a small residual altered blood nasal to the fovea. No treatment was however done to the retinal artery macroaneurysm due to its atypical location and chance of spontaneous involution. In conclusion, retinal artery macroaneurysm at the optic disc is extremely uncommon. Identification of the retinal artery macroaneurysm lesion is more difficult in glaucoma patients due to the large and deep optic cup. Fluorescein angiography remains the main investigative modality to confirm the diagnosis. Spontaneous involution still remains the mainstay of treatment in optic disc retinal artery macroaneurysm.


2014 ◽  
Vol 67 (5-6) ◽  
pp. 185-189
Author(s):  
Marija Trenkic-Bozinovic ◽  
Predrag Jovanovic ◽  
Gordana Zlatanovic ◽  
Dragan Veselinovic ◽  
Aleksandra Aracki-Trenkic ◽  
...  

Introduction. Drusen of the optic nerve head are relatively benign and asymptomatic. They represent retinal hyaline corpuscles resulting from impaired axoplasmic transport of the retinal ganglion cells of optic nerve in front of the lamina cribrosa. They are usually detected accidentally, during a routine ophthalmologic examination. Most patients with optic disc drusen are not aware of the deterioration of their eyesight because of the slow progression of visual field defects. Damage in visual acuity due to optic disc drusen is rare. Case Report. A 27-year-old female patient in the sixth month of pregnancy visited an ophthalmologist because of a visual impairment described as the appearance of mist and shadows over her right eye. When first examined, her visual acuity in both eyes was 20/20. The retinal hemorrhages framing the bottom half of the optic nerve were seen. Complete laboratory and clinical testing as well as specific ophthalmic examinations (photofundus, computerized visual field, optical coherence tomography, and ultrasound) were performed to exclude systemic causes and they presented no risk for the pregnancy. Echosonographic examination confirmed the presence of bilateral optic nerve head drusen. Conclusion. Hemodynamic changes during pregnancy are possible factors for the development of optical disc and retinal hemorrhages. Since treatment of optic disc drusen is limited, recognition of optic nerve drusen as a cause of hemorrhage during pregnancy prevents unnecessary diagnostic and therapeutic interventions.


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