In ophthalmology, retinal laser therapy is a treatment for retinopathy that requires the use of magnifying lens to treat damaged regions of retinal landmarks, hence creating challenges of inverted magnified images and requiring prolonged training. Augmented Reality (AR) can benefit clinicians during retinal laser therapy by guiding them with retinal landmark holograms and contextual information. Though recent developments in AR magnification show that a direct overlay of the magnified scenes can be achieved, retinal laser therapy requires high precision and visual acuity while maintaining the visual perception of the rest of the environment. Therefore, we demonstrate an AR-based selective magnification system that provides contextual and visualization-based guidance to clinicians. An edge-computing architecture is developed for detecting and matching the feature points between the magnified image and color fundus image of the retina to identify the magnified region of retinal landmarks. We showcase how our AR guidance system can assist clinicians during retinal laser therapy.