Idiopathic peripheral retinal telangiectasia (IPT), often termed as Coats disease, can present in a milder form with the onset in adulthood. The goal of this case series study and literature review was to describe and classify different presenting forms and treatment of this entity and to review contemporary methods of its management. Six cases of adult onset IPT were described with the following phenotypes based on fundus ophthalmoscopy, fluorescein angiography, and optical coherence tomography findings: IPT without exudates or foveal involvement, IPT with peripheral exudates without foveal involvement, IPT with peripheral exudates and cystoid macular edema, and IPT with peripheral and macular hard exudates. Treatments applied in this series included observation, laser photocoagulation, and anti-vascular endothelial growth factor (VEGF) treatment with variable outcomes depending upon the extent of IPT, the aggressiveness of laser treatment, and the stringency of follow-up. The accompanying literature review suggests that ablative therapies, especially laser photocoagulation, remain the most effective treatment option in adult-onset IPT, with anti-VEGF therapy serving as an adjuvant procedure. Close follow-up is necessary to achieve and maintain reasonable good visual and morphological results.