Stage 1 Macular Hole (or impending MH): Localized contraction of the perifoveal vitreous causes a tractional detachment of the fovea resulting in a loss of the foveal contour. Stage 1 holes are characterized clinically as a small round yellow spot or ring in the fovea.  Visual acuity is usually better than 20/50. 

Stage 2 Macular Hole: This stage is marked by a small full-thickness retinal break (<400 µm in diameter). This can occur weeks to months following Stage 1 MHs (approximately 50% progress to Stage 2). A further decline in visual acuity is also noted (20/50 to 20/80 range). In most cases, the posterior hyaloid has been confirmed to be still attached to the fovea on OCT analysis. 

Stage 3 Macular Hole: Further progression to a fully developed macular hole that is usually approximately 1/3 disc diameter in size (≥400 µm in diameter). Nearly 100% of stage 2 MHs progress to Stage 3 and the vision further declines to around 20/200. A grayish macular rim often denotes a cuff of subretinal fluid and drusen-like deposits are often observed at the base of the hole. The posterior hyaloid is noted to be detached over the macula with or without an overlying operculum. 

Stage 4 Macular Hole: A fully developed macular hole with a posterior vitreous detachment. The risk of developing a macular hole in the fellow eye is as high as 15%.