Background: Diabetic retinopathy is the third highest cause of functional vision loss in people older than 50 years. There are few measures accessible to prevent diabetic retinopathy beyond control of tight glycemic control, cessation of smoking, BP control and correction of dyslipidemia. Beyond control of systemic factors, laser photocoagulation, Intravitreal anti-VEGF drugs and Intravitreal corticosteroids are the principal therapies to reduce sight threatening DME. Laser photocoagulation and Vitreoretinal surgery are the main treatments for PDR. Objective: We aimed to evaluate changes in SFCT before and after argon laser (PRP) in patients with PDR using spectral-domain optical coherence tomography (SD-OCT). Patients and methods: A prospective observational clinical study on 30 eyes with proliferative diabetic retinopathy. SD-OCT was done before starting PRP, one month and three months following last session of Argon laser. All patients will undergo full medical and ophthalmic history including onset and duration of diabetes, history of ocular surgeries, laser intervention. All patients will undergo complete ophthalmic examination includes Visual acuity: Uncorrected VA (UCVA) &best corrected VA (BCVA),Anterior segment examination using Slit-lamp biomicroscopy ,Intraocular pressure (IOP) measurement by applanation tonometry, Fundus examination ,OCT imaging using SD-OCT  before starting PRP ,one month and three months after last session of PRP and all patients will receive PRP using Argon laser photocoagulation. Results: In patients with diabetic retinopathy treated by pan retinal photocoagulation there is no significant change in sub foveal choroidal thickness noticed after one month but there is a significant change after three months. Conclusion: Proliferative Diabetic Retinopathy cases treated by pan retinal photocoagulation presented by significant improvement in BCVA and there was no significant change in sub foveal choroidal thickness noticed after one month but there is a significant change after three months.