OCT of a patient with a full-thickness macular hole larger than 400 micrometres demonstrates complete separation of the posterior hyaloid from the retinal surface, with a Weiss ring visible clinically. In the Gass classification, this corresponds to:

• A Stage 1 macular hole
• B Stage 2 macular hole
• C Stage 4 macular hole ✓
• D Stage 3 macular hole

Explanation

In the Gass classification, stage 1 holes are impending holes with foveal cystic change and an attached hyaloid, stage 2 holes are small full-thickness breaks under 400 micrometres, stage 3 holes are large full-thickness holes with the posterior hyaloid still attached to the disc margin, and stage 4 denotes a full-thickness hole with complete posterior vitreous detachment confirmed by a Weiss ring. The complete hyaloid separation described here defines stage 4.

Reference: Ryan's Retina, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.