Sir,

Myopic foveoschisis (MF) occurs in 9–34% of highly myopic staphylomatous eyes,1, 2, 3 which may be associated with or may progress to foveal detachment or macular hole, which in turn are associated with decreased visual acuity (VA).1, 2 Therefore, early detection of MF is important before progression. However, the earlier stage of MF has not been described before.

We present one case of a highly myopic eye that had normal retinal findings at presentation before it progressed to the myopic pre-foveoschisis stage, and to MF over a 3-year duration.

Case report

A 60-year-old lady with a bilateral high myopia of −6 D spherical equivalent developed a decreased right VA of 6/21 secondary to MF with foveal detachment. At presentation, her left eye was asymptomatic with a VA of 6/6, with normal fundus examination and optical coherence tomography (OCT) showing posterior staphyloma, steepened foveal contour, and a normal central retinal thickness (CRT) of 159 μm (Figure 1a).

Figure 1
figure 1

A 60-year-old lady with a bilateral high myopia of −6 D spherical equivalent presented with right myopic foveoschisis (MF) and foveal detachment. Her left eye was asymptomatic at presentation. (a) Optical coherence tomography (OCT) (horizontal section) of her left macula at presentation showed a steepened foveal contour in a posterior staphylomatous eye with a normal central retinal thickness (CRT) of 159 μm. Her left VA was 6/6 with normal fundus examination. (b) Two years later, her left eye remained asymptomatic with a VA of 6/7.5. OCT performed 2 years later showed a cleft in the outer plexiform layer at the nasal and temporal parts of the fovea, and elevation of the inner retina, with increase in CRT to 189 μm. (c) One year later, the eye was still asymptomatic with a VA of 6/7.5. OCT of the left macula showed classic MF with a CRT of 275 μm. (d) OCT of the left macula performed 3 months later showed progression of the MF, with CRT increasing to 303 μm.

Full size image

Two years later, her left eye was asymptomatic with a VA of 6/7.5. However, OCT showed the stage of MF as evidenced by a cleft in the outer plexiform layer at the fovea (Figure 1b), and anterior elevation of the inner retina, with an increase in CRT to 189 μm.

One year later, the eye remained asymptomatic with a VA of 6/7.5. However, there was established MF. The CRT was 275 μm (Figure 1c), which further increased to 303 μm 3 months later (Figure 1d).

Comment

Our case report illustrates the stage of myopic pre-foveoschisis preceding MF. At presentation, OCT showed steepening of the foveal contour in a posterior staphylomatous eye. Two years later a cleft developed at the fovea, suggesting early separation of the inner and outer layers at the inner part of the outer plexiform layer of the retina, while CRT remained within normal limits.4 These OCT images show the splitting of the two layers that was initiated at the fovea. The pathogenesis of MF is postulated to be due to retinal stretching from posterior staphyloma and vitreomacular traction, but has not been shown to start at the fovea.1, 2, 3

Patients with high myopia and unilateral MF may be followed up with OCT for the contralateral eye to assess the progression to myopic pre-foveoschisis and MF.