A macular hole is a condition where a full-thickness hole develops in the central retina or macula. We do not know what causes most macular holes (idiopathic), but other conditions which may be associated with macular holes include blunt trauma, macular edema, high myopia, and inflammatory conditions.
Macular holes are classified into stages 1 through stage 4. The earliest stage of macular hole is stage 1, and approximately 60% of stage 1 lesions resolve without treatment. Visual acuity is typically minimally affected.
Vitrectomy with gas bubbles has been used for surgical treatment of macular holes and is usually is not recommended for stage 1 macular holes, but is recommended for stage 2, 3, and 4 holes.
The technique involves removal of the vitreous gel, along with removal of any associated epiretinal membrane tissue. Once the gel and membrane(s) are removed, an air bubble is placed into the vitreous cavity. Then one of two options are chosen:
- Gas Bubbles: A nonexpansile concentration of long-acting gas (SF6 or C3F8) is exchanged with the air. For most patients, strict face-down positioning is recommended for 14 days. Travel by air or to high altitudes is prohibited while the gas bubble is present, as it would expand in the lower atmospheric pressure and severely increase the intraocular pressure. In addition, dental work or general anesthetic with nitrous oxide (laughing gas) is contraindicated because it diffuses into the gas bubble also causing it to expand. Vision is very blurred while the gas bubble is present.
- Silicone Oil: If it is impossible for the patient to maintain the face-down position, a clear silicone oil can be used instead of gas. Face down positioning is overnight, and the patient can be in any position other than flat on his/her back while the silicone oil is present. However, this approach necessitates an additional surgical procedure for oil removal approximately 3 months later, and has a lower success rate than intraocular gas. Vision is also very blurry while the oil is present.