During the Retina Subspecialty Day, Mark W. Johnson, MD, shared pearls for diagnosing and treating myopic traction maculopathy (MTM). Found in highly myopic eyes with posterior staphyloma, MTM appears as extensive schisis-like thickening in the outer retina. Additional findings may include inner retinoschisis, foveal detachment, and lamellar or full-thickness macular hole.
Pathogenesis. “The pathogenesis of MTM is not completely understood,” Dr. Johnson said, “but we have some clues.”
- It almost always occurs within a posterior staphyloma.
- The asymmetry of staphyloma leads to asymmetric macular thickening.
- A dome-shaped macula can be protective, while macular buckling can be curative.
MTM is caused by the relative tautness of the inner retina overlying a posterior staphyloma. There are four main traction mechanisms:
- Vitreomacular traction from partial posterior vitreous detachment (PVD).
- Remnant cortical vitreous after PVD.
- Epiretinal membrane.
- Intrinsic elasticity or noncompliance of the inner limiting membrane (ILM).
Treatment. Some eyes spontaneously resolve through unknown mechanisms, but most eyes worsen slowly over many years. Relatively good preoperative visual acuity is the only factor associated with better final visual acuity. “So it is reasonable to closely follow eyes with good reading vision,” said Dr. Johnson, “and consider surgery by an experienced surgeon as soon as reading vision is significantly compromised.”
To achieve single-operation success, he recommends identifying and relieving the major tractional mechanism using a comprehensive approach, with ILM peeling in every case.
ILM peeling tips. When peeling the ILM, Dr. Johnson prefers a two-step approach. He begins by peeling the cortical vitreous and epiretinal membrane layer, followed by ILM peeling. To mitigate persistent traction near the macular center, the ILM should be peeled close to the staphyloma margins. He also recommends fovea-sparing ILM peeling to minimize the risk of macular hole formation.
Gas tamponade? Gas tamponade is important for eyes with macular hole and is beneficial if macular detachment is present, but it is otherwise unlikely to affect the final outcomes. However, it may hasten recovery.
Even with a comprehensive approach, Dr. Johnson noted that macular thickening may still resolve slowly. Surgical outcomes are generally good and lasting, he said. —Kanaga Rajan, PhD
Watch Retina Subspecialty Day. If you are registered for AAO 2020 Virtual, you have access to the archived presentations on the virtual meeting platform until Feb. 15, 2021. Log in to the virtual meeting platform: Next, from the Lobby screen, select “Sessions” from the top navigation; click “Agenda” from the drop-down menu; and click on the “Friday” tab.
Financial disclosures. Dr. Johnson: Amgen: C; Apellis: S; Aura Biosciences: C; Pfizer: C; Syneos Health: C.
Disclosure key. C = Consultant/Advisor; E = Employee; L = Speakers bureau; O = Equity owner; P = Patents/Royalty; S = Grant support.
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