title: Classification and management of Coats disease: the 2000 Proctor Lecture.
abstract: OBJECTIVE
  To review the methods and results of management in a large series of patients with Coats disease, to determine risk factors for poor visual outcome and enucleation, and to propose a practical classification of Coats disease.
  
  
  METHODS
  In a retrospective consecutive series in 150 patients, Coats disease was defined as idiopathic retinal telangiectasia with intraretinal or subretinal exudation without appreciable signs of retinal or vitreal traction. We reviewed our experience with management, including observation, laser photocoagulation, cryotherapy, and various techniques of retinal detachment surgery and enucleation. The anatomic outcome, complications of treatment, visual results, and reasons for enucleation were tabulated. Factors predictive of poor visual outcome (20/200 or worse) and enucleation were determined using Cox proportional hazards regression models. Based on these observations, a staging classification of Coats disease, applicable to treatment selection and ocular prognosis, is proposed.
  
  
  RESULTS
  In 117 patients (124 eyes) with a mean follow up of 55 months (range, 6 months to 25 years) primary management was observation in 22 eyes (18%), cryotherapy in 52 (42%), laser photocoagulation in 16 (13%), various methods of retinal detachment surgery in 20 (17%), and enucleation in 14 (11%). Anatomic improvement or stability was achieved in 76% of eyes, and final visual acuity was 20/50 or better in 17 eyes (14%), 20/60 to 20/100 in eight (6%), 20/200 to finger counting in 30 (24%), and hand motion to no light perception in 49 (40%) Enucleation was ultimately necessary in 20 eyes (16%). Risk factors predictive of poor visual outcome (20/200 or worse) included postequatorial (P =.01), diffuse (P =.01), or superior (P =.04) location of the telangiectasias and exudation, failed resolution of subretinal fluid after treatment (P =.02), and presence of retinal macrocysts (P =.02). The main risk factors for enucleation were elevated intraocular pressure (greater than 22 mm Hg; P less than or equal to.001) and iris neovascularization (P less than or equal to.001). Coats disease was classified into stage 1, telangiectasia only; stage 2, telangiectasia and exudation (2A, extrafoveal exudation; 2B, foveal exudation) stage 3, exudative retinal detachment (3A, subtotal; 3B, total); stage 4, total detachment and secondary glaucoma; and stage 5, advanced end-stage disease. Poor visual outcome (20/200 or worse) was found in 0% of eyes with stage 1, 53% with stage 2, 74% with stage 3, and 100% of stages 4 and 5 Coats disease. Enucleation was ultimately necessary in 0% of stages 1 and 2, 7% of stage 3, 78% of stage 4, and 0% of stage 5 disease.
  
  
  CONCLUSIONS
  Carefully selected treatment can anatomically stabilize or improve the eye with Coats disease in 76% of eyes. However, poor visual outcome of 20/200 or worse commonly results. Patients who present with stages 1 to 3 Coats disease have the best visual prognosis, and patients with stages 4 and 5 have a poor visual prognosis.
authors.affiliation: Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Shields
authors.forename: C L
authors.initials: CL
authors.lastname: Shields
authors.forename: S G
authors.initials: SG
authors.lastname: Honavar
authors.forename: H
authors.initials: H
authors.lastname: Demirci
authors.forename: J
authors.initials: J
authors.lastname: Cater
mesh_terms: D003452:Cryosurgery; D005122:Exudates and Transudates; D015353:Eye Enucleation; D005500:Follow-Up Studies; D006801:Humans; D017075:Laser Coagulation; D012008:Recurrence; D012164:Retinal Diseases / Q000145:classification* / Q000473:pathology / Q000601:surgery*; D012171:Retinal Vessels / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D012591:Scleral Buckling; D013684:Telangiectasis / Q000145:classification* / Q000473:pathology / Q000601:surgery*; D014792:Visual Acuity