Artifact-Removed Quantitative Analysis of Choriocapillaris Flow Voids

Objectives:To investigate choriocapillaris flow voids (FV) with a new optical coherence tomography angiography (OCTA) image processing strategy that can eliminate artifacts caused by vitreous opacities, sub-retinal pigment epithelium fluid and deposits, and subretinal fluid (SRF) by thresholding the en-face OCT image of the outer retina.Materials and Methods:We retrospectively reviewed medical records of patients with drusen and patients with active central serous chorioretinopathy (CSC). FV number (FVn), average area (FVav), and maximum area (FVmax) and the percentage of nonperfused choriocapillaris area (PNPCA) obtained using the proposed strategy were compared with those obtained by removing only artifacts caused by the superficial capillary plexus (SCP).Results:The SRF group included 21 eyes with active CSC and the drusen group included 29 eyes with nonexudative age-related macular degeneration. FVav, FVmax, FVn, and PNPCA obtained using the algorithm were significantly lower than those obtained by removing only SCP-related artefacts in both groups (all p<0.05). The algorithm was also able to remove 96.9% of artifacts secondary to vitreous opacities and all artifacts secondary to serous pigment epithelial detachments.Conclusion:Choriocapillaris nonperfusion areas on OCTA images may be overestimated in eyes with RPE abnormalities and SRF due to artifacts. These artifact areas on choriocapillaris OCTA images can be removed using thresholded images of the outer retina en-face OCT scans. Our new artifact-removal strategy is useful in the assessment of choriocapillaris FV in eyes with SRF, drusen, drusen-like deposits, and pigment epithelial detachment

Newton-GMRES algoritmalarında önşartlandırıcı seçim ve geliştirmesi.

This thesis consists of the choice, application and analysis of a preconditioner for a supersonic flow solution through Newton-GMRES (generalized minimal residual) Krylov subspace method and the comparison of the results with unpreconditioned Newton-GMRES method and Newton’s methods. Three dimensional Euler equations are used for the analysis. These Euler equations are discretized, then solved using Newton’s method and the generalized minimal residual method is used to solve the resulting linear system. The results and the computational time for this Newton-GMRES method approach are then obtained to be compared with those for the same method preconditioned using incomplete lower-upper factorization and the regular Newton’s method. The calculation of the Jacobian matrix necessary for the preconditioner and the Newton’s method is done analytically.M.S. - Master of Scienc

Macular Burns from Nonmedical Lasers

Laser devices are widely used for medical, military, industrial and entertainment purposes. This extensive and unregulated use of lasers can cause a variety of maculopathies that can result in permanent vision loss. Uncontrolled and inappropriate use of laser instruments should be prevented with strict rules. We strongly emphasize the importance of changing the general misperception that lasers are safe to use for entertainment purposes. In this study we aim to report the clinical features of three patients with a history of maculopathy caused by exposure to laser light in an entertainment venue

Occult Macular Dystrophy

Occult macular dystrophy is an inherited macular dystrophy characterized by a progressive decline of bilateral visual acuity with normal fundus appearance, fluorescein angiogram and full-field electroretinogram. This case report presents a 20-year-old female patient with bilateral progressive decline of visual acuity for six years. Her visual acuity was 3-4/10 in both eyes. Anterior segment and fundus examination, fluorescein angiogram and full-field electroretinogram were normal. She could read all Ishihara pseudoisochromatic plates. Fundus autofluorescence imaging was normal. There was a mild central hyporeflectance on fundus infrared reflectance imaging in both eyes. Reduced foveal thickness and alterations of the photoreceptor inner and outer segment junction were observed by optical coherence tomography in both eyes. Central scotoma was also found by microperimetry and reduced central response was revealed by multifocal electroretinogram in both eyes. These findings are consistent with the clinical characteristics of occult macular dystroph

Sjogren syndrome and lipid keratopathy

Bu yazının amacı, Sjögren sendromu nedeniyle oluşan korneal neovaskülerizasyon ve se- konder lipid keratopatili bir olguyu sunmaktır. 38 yaşındaki kadın hasta bilateral korneal opasite ve 1 yıldır şiddeti artmış oküler iritasyon ve fotofobi ile kliniğimize sevk edildi. Hasta 10 yıl önce Sjögren sendromu tanısı almıştı ve 8 yıldır da kuru göz nedeniyle suni gözyaşı kul- lanıyordu. Her iki göze 7 yıl önce kalıcı punktum oklüzyonu yapılmıştı. Günde iki kez siklos- porin A %0,05 (Restasis, Allergan) (CSA) kullandığı suni gözyaşına eklendi. 6 ay sonrası tüm semptomları, lipid birikimi ve korneal vaskülerizasyon dışındaki tüm bulguları geriledi. Ciddi komplikasyonlara yol açabilecek kuru göz hastalığı dikkatli tedavi edilmeli ve takipleri düzenli bir şekilde yapılmalıdır.The purpose of this paper is to report a case of bilateral secondary lipid keratopathy and corneal vascularization as a result of Sjogren syndrome. A 38-year old woman was referred to our clinic with bilateral corneal opacity, ocular irritation and photophobia for 1 year. She had a history of Sjogren syndrome for 10 years and dry eye treatment with eye drops for 8 years. Permanent punctal occlusion had been performed 7 years ago in both eyes. For treatment Cyclosporine A, %0.05 (Restasis, Allergan) (CSA) was added to treatment twice a day, along with artificial tears. After 6 months all symptoms and signs other than lipid accumulation and corneal vascularization got better. Dry eye disease that can lead to serious complications should be treated with caution and follow-up should be done in an orderly manner

Treatment Outcomes in Patients with Polypoidal Choroidal Vasculopathy

Objectives: To report outcomes of photodynamic therapy (PDT) and combined therapy with PDT and intravitreal bevacizumab (IVB) in patients with polypoidal choroidal vasculopathy (PCV). Materials and Methods: Thirty-four eyes of 31 patients with subfoveal PCV were evaluated. Nine eyes were treated with PDT and 25 eyes treated with combined therapy of PDT and IVB. All eyes had a follow-up period of at least 12 months. In this retrospective study the demographic features, best corrected visual acuity, fundus color photography, optical coherence tomography, fluorescein angiography and indocyanine green angiography of the 34 eyes were evaluated. Results: Visual acuity improved but did not change significantly in the patients treated with PDT and combined PDT+IVB therapy (p=0.149; p=0.087). Although the mean central foveal thickness decreased in both groups, there was no statistically significant difference between groups (p=0.98). The polypoidal lesions regressed in 6 (66.7%) of 9 eyes in the PDT monotherapy group and 16 (64%) of 25 eyes in the PDT+IVB combined therapy group. Conclusion: Both PDT and a combined therapy of PDT and IVB yielded successful outcomes in patients with PCV