Retinoschisis

57.1General Considerations1

57.1.1 Anatomy and Pathophysiology

The typically bilateral lesion appears in the inferotemporal, occasionally superotemporal, quadrant, and results in an absolute scotoma as the layers of the neuroretina are split2 and the nerve connections are broken.3

Clinical recognition of the condition is somewhat difficult because a chronically detached retina bears some similarity to it, although the latter does not show the “beaten metal” appearance of a retinoschisis. OCT gives the definite answer in differential diagnostics.

The retinoschisis may be stationary or progressive; the latter may be partially explained by the fact that these eyes very rarely have a PVD, resulting in a constant, dynamic traction acting upon the inner wall of the cavity. RD may also develop if breaks are present both in the anterior and posterior walls of the retinoschisis cavity (see Fig. 57.1), and the RD may also be progressive.

57.1.2 Prophylactic Laser Treatment

It is very difficult to argue against the concept of walling-off the retinoschisis (see Sect. 30.3.4) since such laser treatment is quite effective. Conversely, the progression of the condition, whether it is the enlargement of the retinoschisis cavity or of the resulting RD, threatens with severe visual loss, and the prognosis of surgery is poor.

1Senile (degenerative), not juvenile, type of retinoschisis is discussed here.

2At the outer plexiform layer.

3This is why the term “retinoschisis” should not be used in eyes with an optic pit (see Sect. 51.1).

F. Kuhn, Vitreoretinal Surgery: Strategies and Tactics,

DOI 10.1007/978-3-319-19479-0_57

a

R

RSC

C

b

c

Fig. 57.1 Schematic representation of the progression of retinoschisis. (a) With a break (thin arrow) in the inner wall of the retinoschisis cavity, there is a risk that the lesion spreads (thick arrow) toward the macula (not shown here). (b) With an additional break (thin arrow) in the outer wall of the retinoschisis cavity, there is a risk that the fluid from the vitreous cavity also spreads through the retina into the subretinal space. (c) What was only a threat on (b) has become a reality; now the macula is at risk from both the retinoschisis and a true RD (thick arrows). RSC retinoschisis cavity, R retina, C choroid

The goal of the laser retinopexy is to create a firm chorioretinal adhesion in the normal retina to prevent the pathology from breaking through. This requires treatment with rather strong laser spots so that the inner retinal layers are also incorporated into the scar.

If the retinoschisis itself or the RD is progressing toward the macula, surgery is the only option left. This is a rather difficult operation because the posterior cortical vitreous is very adherent to the thin inner wall of the cavity. PVR is a rather common postoperative complication; therefore, the VR surgeon should be rather pessimistic during counseling.

Pearl

Retinoschisis is a condition where PPV is best avoided, rather than recommended; however, progression of the pathology may make PPV unavoidable.