Acquired tractional retinoschisis with giant outer - layer break underneath macula.

A 41-year-old female patient of Zambian nationality presented with right eye (RE) best-corrected visual acuity (BCVA) counting fingers ½ meters. Fundus showed clear media, neurosensory detachment with schisis-detachment (SD) with a large outer layer break (OLB) involving the macula. On fundus imaging using Zeiss Visucam camera, the OLB with underlying SD was roughly 5-6 DD in greatest linear dimension, had one edge of the break as scrolled band of tissue attached to the RPE superiorly above the arcade, whereas the other edge was lifted off and attached to inner retina inferiorly as a wavy yellow line. Adjacent to SD was localized retinal detachment upto the inferior arcade and little beyond. Supero-temporal to this schisis—retinal detachment (RD) complex were 3 large inner layer breaks 1-1.5 DD in size. The entire lesion was lifted by a band of fibrovascular tissue running supero – temporally and ending at parsplana [Fig. 1]. No other pathologic finding was seen in the other parts of RE retina or in the left eye (LE) fundus. A diagnosis of acquired tractional retinoschisis as a sequelae of healed idiopathic peripheral occlusive vasculitis was made. Meticulous 25 gauge pars plana vitrectomy (PPV) was done with posterior hyaloid dissection followed by transection of fibrovascular band post cauterisation and then resection of inner schisis cavity was completed. Barrage endolaser around the lesion under perfluorocarbon liquid and silicone oil endotamponade was done to attach the retina [Fig. 2]. Three weeks postsurgery foveal contour was good with complete re-attachment of inner – retinal layers. BCVA improved to 20/120 with + 3.5 DS. After 3 months, silicone oil removal was done. At final visit retina was stable with 20/120 BCVA in OD.

Figure 1

Fundus images of the right eye showing: (a) Montage image of central and supero – temporal quadrant showing the entire retinoschisis - schisis detachment - retinal detachment complex with tractional fibrovascular band, (b) posterior pole image, (c) 3 large inner layer breaks (red arrows), (d) extent of large outer layer breaks (blue arrows), (e) extent of schisis-detachment below the outer layer breaks (blue arrow) and (f) extent retinal detachment beyond schisis-detachment underneath macula

Figure 2

Intra operative photos captured on smartphone from TV monitor showing (a) Parsplana core vitrectomy, (b) Peripheral and shave vitrectomy, (c) endodiathermy to inner layer breaks and the fibrotic band, (d) trans-section of fibrotic band by cutter, (f) PFCL injection to flatten retina and (g) Barraged retinoschisis with flattened retina following silicone oil injection

Discussion

Acquired retinoschisis (RS) is an abnormal splitting of neurosensory retina at the level of outer plexiform layer with a prevalence of 1.65% to 7%.[12] OLB usually are round or oval and measure 1–3 disk diameters and have a prevalence of 11-24%.[3] Excluding this case, only 9 known instances of giant (>3DD) OLB have been reported in RS but none underneath macula.[4]

Schisis-detachment results from movement of schitic fluid through outer layer breaks to cause an area of localized retinal detachment. Mostly it is asymptomatic as the typical behavior of schisis-detachment is that only a limited amount of fluid passes into the subretinal space, probably because of the very viscid nature of the intracystic fluid. However, especially if very large outer layer break occurs, progressive retinal detachment results as evident in this case. The ratio of the occurrence of asymptomatic “schisis-detachment” to the progressive symptomatic variety which requires surgery is about 178 to 1.[3] RS with progressive, frank, RD is a rare complication affecting 1 in 2000 patients associated with breaks in both layers, or with only outer layer breaks.[13] Surgical intervention in the form of PPV is indicated for RS with progressive RD and for SD with rare posterior extension of schitic fluid.[3] This case becomes atypical in its presentation by having a traction element to the RS-SD-RD complex, apart from a rare giant outer layer break underneath macula.

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Conflicts of interest

There are no conflicts of interest.