To present the clinical characteristics and rational treatment of macular hole (MH) after the diabetic vitrectomy (DV) in patients with proliferative diabetic retinopathy (PDR).

All patients had received initial vitrectomy to treat complications of PDR. Recruited patients were divided to two groups: the persistent MH group, who had MH before the primary DV (group 1); and the newly-developed MH group, who developed MH after a successful primary DV (group 2). The patients' demographic data, records of ophthalmological examinations, and surgical procedures were collected, including best-corrected visual acuity before and after each operation, fundus changes, as well as MH repairing techniques. The extent of fibrovascular proliferation(FVP) was separated into four grades based on the severity of vitreoretinal adhesion : multiple-point adhesions with or without one site plaque-like broad adhesion (grade 1), broad adhesions in more than one but fewer than three sites, located posterior to the equator (grade 2), broad adhesions in more than three sites, located posterior to the equator or extending beyond the equator within one quadrant (grade 3), and broad adhesions extending beyond the equator for more than one quadrant (grade 4). The extent of retinal detachment (RD) was classified into "within the arcade" or "beyond the arcade". The macular structure was evaluated by optical coherence tomography (OCT). All patients had a follow-up duration of more than three months after the final surgical procedures.

Three different surgical techniques were used to treat MH: standard internal limiting membrane (ILM) peeling, inverted ILM flap insertion into the MH, and lens anterior or posterior capsular flap insertion into the MH. The indication(s) for each technique were:

standard ILM peeling was performed if no ILM peeling had been done in the previous surgery, and the MH size was less than 500um in an attached retina; inverted ILM flap insertion was performed if no ILM peeling had been done in the previous surgery, with a detached retina; lens anterior capsule flap insertion was performed if cataract surgery was performed in the same setting with no ILM tissue available; lens posterior capsule flap insertion was performed in a pseudophakic eye with no ILM tissue available. Only descriptive statistics was obtained.

Inclusion Criteria:

• Proliferative diabetic retinopathy patients presenting with macular hole after primary diabetic vitrectomy
• The persistent MH group after surgery, who had MH before the primary DV
• Newly-developed MH group, who developed MH after a successful primary diabetic retinopathy

Exclusion Criteria:

• Patients with peripheral breaks
• Patients with macular hole before surgery, which closed after primary diabetic retinopathy
• Missing clinical data

Patients from January 2010 to May 2017 treated by a single surgeon (Y.C.M) at National Taiwan University Hospital were retrospectively reviewed.