Role OF OCT-A TO Detect Possible Retinal Vascular Complications of Sofosbuvir in Patients With Hepatitis C

The purpose of this study is to prospectively evaluate the value of Optical coherence tomography angiography (OCT-A) for the of detection of suspected retinal complications With Sofosbuvir (Sovaldi) in Patients With Hepatitis C Virus Infection

During 3 months duration ( the treatment course duration) , Optical coherence tomography angiography (OCT-A) will be performed to 30 eyes of 30 patients with a documented diagnosis of chronic hepatitis C before and after receiving dual-therapy planning (Daclatasvir - Sofosbuvir (Sovaldi)) , normal renal functions And Rheumatoid factor tests , will undergo a comprehensive ophthalmic examination including:

* Manifest refraction
* Corrected distance visual acuity
* Anterior segment examination using slit lamp and tear film breakup time test
* Fundus examination

Recent Optical coherence tomography angiography (OCT-A) will be performed to all patients before Treatment Administration.

Examination will be performed using "Optovue AngioVue®" "Optovue, Inc., Fremont, CA", which uses split-spectrum amplitude-decorrelation angiography algorithm, which minimizes motion noise. This system also allows quantitative analysis, since it provides numerical data about flow area and flow density maps.

The patient will be examined before and after finishing the treatment course

\* Optical coherence tomography angiography (OCT-A) image acquisition OCT-A will be done for all patients who are instructed to focus on a fixation target. OCTA images are obtained using the "RTVue XR Avanti (AngioVue; Optovue Inc, Fremont, California, USA)" machine and the incorporated "AngioVue OCT-A" system. Algorithm used is Split-Spectrum Amplitude Decorrelation Algorithm (SSADA). The scans which will be included in the study are of high signal strength more than 0.7 and they will be carefully inspected for motion artifacts. Automatic segmentation of intraretinal layers will be done using the automated software of the machine (version 2016.2.0; Optovue Inc). Angio-retina scan sizes in this study will be 6 X 6 mm for all eyes. Assessment of the macular vessel density will be done for superficial vascular layer, capillary plexus, deep capillary plexus and all retinal plexuses). Assessment of the foveal avascular zone on both superficial vascular layer (SVL) and deep capillary plexuses (DCP); including its size, perimeter and circularity (regularity) index. Circularity index is a measure of compactness of a shape relative to a circle. The circularity index of a circle is 1.0. Thus, a ratio closer to 0 indicates an irregular shape, and that closer to 1.0 indicates a circular shape.

All results will be in numerical values (percentage) to compare retinal vascularity before and after using the drug. Best corrected visual acuity (in values from o.o5 to 1.0) , dryness (in seconds) will be also measured before and after drug administration and it will be compared .

Eligibility Criteria:
Inclusion Criteria:

* Age between 20 and 80 years.
* Patients with chronic hepatitis C enrolled for (Daclatasvir - Sofosbuvir (Sovaldi)) .
* Patients who have normal ocular and fundoscopic examination before the onset of treatment.

Exclusion Criteria:

* Relapsed cases who have formerly taken the antiviral therapy (depending on the basis of medical record and filing system), or treated with interferon for any other cause .
* Patients with elevated renal functions or positive Rheumatoid factor (as a clue to diagnose Purtscher like retinopathy which is a rare presentation of cryoglobulinemia ,considered one of extra hepatic manifestations of HCV )