Macular hole opercula. Ultrastructural features and clinicopathological correlation

Area of Science:

• Ophthalmology
• Retinal Surgery
• Cell Biology

Background:

• Idiopathic full-thickness macular holes (FTMH) are a significant cause of vision loss.
• The composition of excised opercula during vitrectomy surgery is not fully understood.
• Understanding opercula composition may correlate with surgical outcomes.

Purpose of the Study:

• To examine the ultrastructure of opercula from FTMH excised during vitrectomy.
• To correlate these ultrastructural findings with surgical success and visual acuity outcomes.

Main Methods:

• Opercula from 18 eyes with stage 3 FTMH were collected during vitrectomy.
• Specimens were processed for transmission electron microscopy.
• Ultrastructural features were correlated with pre- and post-operative clinical data.

Main Results:

• Vitreous collagen was present on all opercula; internal limiting membrane fragments were in 61%.
• Eleven opercula (61%) contained only glia (astrocytes, Müller cells).
• Seven opercula (39%) contained glia plus neurites and synaptic complexes (some from cone photoreceptors).
• Initial surgical closure rates were significantly higher for glial-only opercula (82%) versus those with neurites (14%) (P = .01).
• Final visual acuity did not differ significantly between groups after reoperation, but better acuity (≥20/40) was more likely with glial-only opercula.

Conclusions:

• Two distinct opercula types exist: glial-only (pseudo-opercula) and glia/cone (true opercula).
• Pseudo-opercula may indicate foveal dehiscence with minimal tissue loss, while true opercula suggest significant foveal cone avulsion.
• True opercula correlate with poorer initial anatomical and visual outcomes, possibly due to foveal tissue loss and tractional forces on the retina.