Egg Tart remains in doubt for the Epsom Handicap as the mare continues be treated for an eye irritation.

The Chris Waller-trained second favourite for Saturday's $1 million race at Randwick was examined by two veterinarians on Wednesday and although there were signs of improvement she has not been passed fit to race.

Racing NSW Veterinarian Dr Tania Selig inspected the near side eye of Egg Tart and confirmed the four-year-old still had a painful irritation.

She said there had been slight improvement since Racing NSW senior veterinarian Dr Craig Suann checked Egg Tart on Tuesday.

Stable veterinarian Dr Ross Alexander also told stewards the irritation had slightly improved.

Dr Suann will inspect Egg Tart again on Thursday and a final decision on whether she can run will be made following an examination on Friday afternoon.

Egg Tart has been treated with anti-inflammatory drugs but the time frame to use that medication was over.

"It'll be a matter now of just how the horse responds without that anti-inflammatory treatment," Racing NSW steward Marc Van Gestel told Sky Sports Radio.

"We're not under any illusions that the horse is a definite starter, but we'll give the horse every chance to get to the barriers on Saturday."

Egg Tart is the $4.80 second Epsom elect behind the Pat Webster-trained Happy Clapper ($3.80).

A two-time Group One winner, Egg Tart claimed six successive races before a last-start second to Deploy in the Group Two Theo Marks Stakes (1300m) on September 9.

Egg Tart galloped with stablemate Foxplay on Tuesday.