749 research outputs found
Effect of corneal light scatter on vision: a review of the literature
The cornea is the transparent connective tissue window at the front of the eye. The physiological role of the cornea is to conduct external light into the eye, focus it, together with the lens, onto the retina, and to provide rigidity to the entire eyeball. Therefore, good vision requires maintenance of the transparency and proper refractive shape of the cornea. The surface structures irregularities can be associated with wavefront aberrations and scattering errors. Light scattering in the human cornea causes a reduction of visual quality. In fact, the cornea must be transparent and maintain a smooth and stable curvature since it contributes to the major part of the focusing power of the eye. In most cases, a simple examination of visual acuity cannot demonstrate the reduction of visual quality secondary light scattering. In fact, clinical techniques for examining the human cornea in vivo have greatly expanded over the last few decades. The measurement of corneal back scattering qualifies the degree of corneal transparency. The measurement of corneal forward-scattering quantifies the amount of visual impairment that is produced by the alteration of transparency. The aim of this study was to review scattering in the human cornea and methods of measuring it
Rapidly progressing subperiosteal orbital abscess: an unexpected complication of a group-A streptococcal pharyngitis in a healthy young patient
INTRODUCTION: Complications associated to group-A streptococcal pharyingitis include non-suppurative complications such as acute rheumatic fever and glomerulonephritis and suppurative complications such as peritonsillar or retropharyngeal abscess, sinusitis, mastoiditis, otitis media, meningitis, brain abscess, or thrombosis of the intracranial venous sinuses. CASE PRESENTATION: We described a case of a 15-year-old patient with a history of acute pharyngodinia early followed by improvise fever and a progressive formation of a diffuse orbital edema, corneal hyperaemia, diplopia and severe decrease of visual acuity. The patient was surgically treated with functional endoscopic sinus surgery (FESS) after the response of a maxillofacial computed tomography scans that showed a pansinusitis complicated by a left orbital cellulites. Numerous colonies of Streptococcus pyogenes were found in the samples of pus and an antibiotic therapy with meropenem was initiated on the basis of the sensitivity test to antibiotics. The patient was finally discharged with diagnosis of left orbital cellulites with periorbital abscess, endophtalmitis and acute pansinusitis as a consequence of streptococcal pharyngitis. CONCLUSION: The case highlights the possible unusual complication of a group-A streptococcal pharyingitis in a immunocompetent child and the needing of a prompt surgical and medical approach toward the maxillofacial complications associated to the infection
Qualitative and Quantitative Assessment of Vascular Changes in Diabetic Macular Edema after Dexamethasone Implant Using Optical Coherence Tomography Angiography
The aim of this study was to investigate retinal and choriocapillaris vessel changes in diabetic macular edema (DME) after the intravitreal dexamethasone implant (IDI) using optical coherence tomography angiography (OCTA). Moreover, a comparison between morphological and functional parameters of DME and healthy patients was performed. Twenty-five eyes of 25 type 2 diabetic retinopathy patients complicated by macular edema (DME group) and 25 healthy subjects (control group) were enrolled. Superficial capillary plexus density (SCPD) and deep capillary plexus density (DCPD) in the foveal and parafoveal areas, choricapillary density (CCD) and optic disc vessel density (ODVD) were detected using OCTA at baseline and after 7, 30, 60, 90 and 120 days post injection. Best corrected visual acuity (BCVA), retinal sensitivity, and central retinal thickness (CMT) were also evaluated in both groups of patients. A statistically significant difference between the two groups (DME and controls) was found in terms of functional (MP, p < 0.001 and BCVA, p < 0.001) and morphological (CMT, p < 0.001; SCPD in the parafoveal area, p < 0.001; DCPD in the foveal area, p < 0.05 and parafoveal area, p < 0.001; CCD, p < 0.001) parameters. After the treatment, SCPD and DCPD in the foveal and parafoveal areas did not modify significantly during the follow up
Screening Programs for Lynch Syndrome in Italy: State of the Art and Future Challenges
 
Identificazione di posizione e di orientamento di magneti per applicazioni medicali
creazione della struttura per la verifica della possibilità di individuare la posizione e l'orientamento di magneti per applicazioni medicaliope
Phacoemulsification Wound Burn and Its Management
Introduction: The production of ultrasonic energy during phacoemulsification is associated with heat generation that could damage ocular tissues, particularly at the corneoscleral wound site. Case presentation: This study presents an 89-year-old patient with senile hypermature cataract and Fuchs endothelial dystrophy developing severe thermal corneoscleral injury during phacoemulsification. At presentation, visual acuity was finger count at 40 cm and there was a 1 × 2-mm area of corneal melting at the corneal tunnel with diffuse corneal oedema. After 1 month, a temporal circular corneal patch graft was applied to the corneal burn. A penetrating keratoplasty was performed 16 months after the first surgery. Conclusion: Corneal surgery, including lamellar patch grafts and full-thickness penetrating grafts, could be used, when necessary, to restore the cornea's integrity. These procedures could eliminate corneal scarring, decrease astigmatism, and improve vision in patients with phacoemulsification burns
Subretinal recombinant tissue plasminogen activator and pneumatic displacement for the management of subretinal hemorrhage occurring after anti-VEGF injections for wet AMD
We describe three cases of submacular hemorrhage that occurred two to four days after anti-VEGF intravitreal injection for occult choroidal neovascularisation in age-related macular degeneration and their management with 25 gauge pars plana vitrectomy with injection of subretinal recombinant tissue plasminogen activator (rTPA) followed by fluid-air exchange and postoperative prone position. Vitrectomy, subretinal rTPA injection and fluid-gas exchange apply as a safe and effective treatment in these cases. Functional results seem to be positive especially if surgical treatment is promptly performed
Capecitabine-Related Fourth Nerve Palsy: A Case Report
Introduction: Capecitabine has rarely been associated with neurotoxicity. Cerebellar ataxia, multifocal leukoencephalopathy, and sensorimotor peripheral neuropathy have been reported in the literature. A case of 6th nerve palsy associated with capecitabine has also been described. This article reports the first case of capecitabine-related 4th nerve palsy. Case presentation: A 72-year-old Caucasian woman was referred by the Oncology Department because she had been complaining of binocular diplopia for 6 months. The symptoms started 1 month after the introduction of capecitabine. A diagnosis of right 4th nerve palsy was made using the Parks three-step test and the Hess test. Neuroimaging analysis was negative. A slow but progressive deterioration of function was confirmed during a year of follow-up. On suspicion of a chemotherapy-related palsy, capecitabine was discontinued and switched to vinorelbine. Subsequent improvement of the clinical picture was confirmed within 2 months. Conclusion: The recognition of chemotherapy-related neurotoxicity is of paramount importance in the management of oncology patients. Once secondary invasion of the brain or the orbit by the tumor itself is ruled out, it must be suspected to prevent further deterioration
Functional and anatomical outcomes of brolucizumab for nAMD in a real-life setting
To report long-term outcomes of brolucizumab in neovascular age-related macular degeneration (nAMD) treatment. Records from 74 patients were retrospectively reviewed. Both naïve eyes and those previously treated with other antiVEGF agents were included. Primary outcomes included variation in best corrected visual acuity (BCVA), central subfield thickness (CST), intraretinal fluid (IRF), subretinal fluid (SRF), and pigment epithelial detachment (PED) dimensions. Outcomes were reviewed after the loading phase, at week 24, and at last follow-up. IOI occurrence represented the secondary outcome. BCVA improved significantly in both groups. In switched eyes, IRF and SRF were significantly reduced at every timepoint, with CST reduction from week 24 (p = 0.005). In naïve group, CST decreased from the loading phase (p = 0.006) and all patients showed dry macula from week 24. A significant reduction in PED maximum high was demonstrated in both groups. In seven naïve eyes, PED completely reabsorbed; a slight increase in PED horizontal maximal diameter was also observed from week 24. IOI occurred in 5.4% of cases. In conclusion, brolucizumab showed a strong drying effect, permitting functional improvement together with fluid reabsorption and an encouraging modification of PED dimension, especially on naïve patients. These results together with the extension of treatment intervals make brolucizumab an efficient therapeutic strategy for nAMD
A Deep Learning Method for Automatic Identification of Drusen and Macular Hole from Optical Coherence Tomography
Deep Learning methods have become dominant in various fields of medical imaging, including ophthalmology. In this preliminary study, we investigated a method based on Convolutional Neural Network for the identification of drusen and macular hole from Optical Coherence Tomography scans with the aim to assist ophthalmologists in diagnosing and assessing retinal diseases
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