Classification of primary angle closure disease

PURPOSE OF REVIEW: Primary angle closure disease, PACD, has had a plethora of classifications and terminologies. The International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification was a simple classification, extremely useful in surveys, but could not be clinically applied because of the varied presentation of PACD. RECENT FINDINGS: Reviewing the literature, it was seen that the landmarks in progression of PACD were an anatomical predisposition; iridocorneal apposition/adhesions; chronic rise in intraocular pressure (IOP), despite an iridotomy; and glaucomatous optic neuropathy. Therefore, a staging system for PACD is proposed. PACD suspect--occludable angle; PACD I--occludable angle with evidence of closure, but a normal IOP after iridotomy; PACD II--peripheral anterior synechiae in an occludable angle with a chronically raised IOP after iridotomy, with or without a suspicious optic nerve head; and PACD III--peripheral anterior synechiae in an occludable angle, with a raised IOP after iridotomy, and glaucomatous optic neuropathy. SUMMARY: This proposed classification has amalgamated all the clinically described subtypes of PACD--subacute, acute, chronic, symptomatic, and asymptomatic--into a staging, based on extent of damage to the outflow channels and optic nerve head, providing a basis for standardized therapy and possibly a quantifiable long-term prognosis.