Differentiation of Retinoschisis From Rhegmatogenous Retinal Detachment
Retinoschisis must be differentiated from RRD (Table 16-4). Retinoschisis causes an absolute scotoma, whereas RRD causes a relative scotoma. Tobacco dust, hemorrhage, or both are present in the vitreous with retinoschisis only in rare instances, whereas they are commonly observed with RRD. Retinoschisis has a smooth surface and usually appears dome shaped; in contrast, RRD often has a corrugated, irregular surface. In long-standing RRD, however, the retina also may appear smooth and thin, similar to its appearance in retinoschisis. Whereas long-standing RRD may also show atrophy of the underlying RPE, demarcation line(s), and degenerative retinal schisis (macrocysts), the underlying RPE is normal in eyes with retinoschisis.
Table 16-4 Differentiation of Rhegmatogenous Retinal Detachment and Retinoschisis
Retinoschisis is associated with approximately 3% of full-thickness retinal detachments. Two types of schisis-related detachments occur. In the first type, if holes are present in the outer but not the inner wall of the schisis cavity, the contents of the cavity can migrate through a hole in the outer wall and slowly detach the retina (see Fig 16-18). Demarcation lines and degeneration of the underlying RPE are common. A demarcation line in an eye with retinoschisis suggests that a full-thickness detachment is present, or was formerly present and has spontaneously regressed. This type of retinoschisis detachment usually does not progress, or it progresses slowly and seldom requires treatment.
In the second type of schisis detachment, holes are present in both the inner and outer layers. The schisis cavity may collapse, and a progressive RRD may result. Such detachments often progress rapidly and usually require treatment. The causative breaks may be located very posteriorly and thus may be difficult to repair with scleral buckling. Vitrectomy may be appropriate.
Byer NE. Long-term natural history study of senile retinoschisis with implications for management. Ophthalmology. 1986;93(9):1127–1137.
Gotzaridis EV, Georgalas I, Petrou P, Assi AC, Sullivan P. Surgical treatment of retinal detachment associated with degenerative retinoschisis. Semin Ophthalmol. 2014;29(3):136–141.
Ip M, Garza-Karren C, Duker JS, et al. Differentiation of degenerative retinoschisis from retinal detachment using optical coherence tomography. Ophthalmology. 1999;106(3):600–605.
Xue K, Muqit MMK, Ezra E, et al. Incidence, mechanism and outcomes of schisis retinal detachments revealed through a prospective population-based study. Br J Ophthalmol. 2017; 101(8):1022–1026.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.