Intravitreal Gas Injection with Laser Photocoagulation for Highly Myopic Foveoschisis

Written by: Prethy Rao, MD

Zhu X, Shen P, Li C, Li H, Huang H, Shi K, Wang L, Zhang X, Lu L. Retina. 2019 Jul;39(7):1305-1311

Myopic macular foveoschisis in patients is often a daunting clinical finding in many practices as progression and surgical outcomes are often variable. While present in 15-20% of myopic patients, progression to foveal detachment can occur in 35-72% of cases.  Pars plana vitrectomy with or without ILM peeling and gas remains one of the mainstay treatments for progression, however, risk of inducing a macular hole (16-20% in some reports) or a retinal break with a detachment are common.

In the June issue of Retina, Zhu and colleagues describe a novel surgical approach that may be done in the office to treat progressive myopic foveoschisis (< -6.00 diopter spherical equivalent or axial length  >= 26 mm). Twenty-three patients (30 eyes) underwent a combination of intravitreal C3F8 injection and temporal macular last photocoagulation with a mean follow up of 20.8 months.  Sixteen eyes (69.5%) had a baseline foveal detachment.

In brief, an anterior chamber paracentesis is performed followed by an intravitreal injection of 0.5-0.7 mL of 66% C3F8 gas at either the 10 or 2 o’ clock positioning 3.5 mm posterior to the limbus. Patients are then instructed to be face down for 3 weeks. At 1 week post procedure, patients are brought back and 2-3 rows of light focal laser is performed in a “C” shaped fashion on the temporal side of the foveal avascular zone (“½ papillary diameter temporal to the fovea”) with the following parameters: 532 nm green laser, 100 mm spot size, laser power 100–150 mW, duration of exposure 100 ms.  A repeat injection was performed if there was less than a 50% reduction in foveal thickness.

At final follow up, 76.7% had complete or partial attachment with a single or multiple injections. Seventeen eyes (56.7%) had complete attachment. Twelve eyes (40%) received a second injection 1 month after the initial treatment.  While the authors report trends toward visual improvement, there was no statistically significant differences in mean and postoperative visual acuities. One eye developed a peripheral tear 5 months later and 1 eye developed a macular hole requiring a pars plana vitrectomy.

This paper illustrates a unique technique for a tough macular progressive macular disease. This technique may be a potential non-invasive option to offer patients who may not necessarily want incisional surgery or are not healthy enough for the operating room while achieving similar anatomic outcomes to vitrectomies.