7.5 Retinal Dialysis

7.4Aphakic RRD

Studies have been performed in this area in the 1960s and 1970s when intracapsular cataract surgery and aphakia were common (Menezo et al. 1977; Snyder et al. 1979; Ramos et al. 2002; McDonnell et al. 1985; Tuft et al. 2006). Schepen’s group in 1973 showed an increase in nasal breaks in aphakia versus phakia, 65 and 50.6 %, respectively (Yoshida et al. 1992). The older studies used a system of counting the number of breaks in each quadrant, providing a total number of breaks in each quadrant over a cohort. Applying statistical analysis using this methodology is more complicated because breaks from the same eye are not independent variables. The use of this method explains the increased percentages described in these studies. Similarly, Phillips in 1963 found increased rates of breaks anteriorly, nasally and inferonasally in aphakic retinal detachment compared with phakic retinal detachments (Phillips 1963). His group attempted to exclude patients with vitreous loss during cataract surgery from analysis.

7.5Retinal Dialysis

7.5.1Clinical Features

Retinal dialysis is a dehiscence of the anterior retina at the ora serrata. There is classically no posterior vitreous detachment. This means that the RRD progresses very slowly and often presents by coincidental observation or when the macula finally detaches. In the latter situation, because of the slow onset and delay in noticing the foveal detachment, visual recovery is seldom complete even after successful surgery. The chronicity results in subretinal fibrosis and retinal cysts,

but a low rate of preretinal PVR is described (Kennedy et al. 1997). If PVR is present, subretinal bands are more common than other types of PVR. The dialysis is usually stiff and smooth-edged and the retinal detachment immobile.

A separation of the vitreous base is sometimes seen as a ‘bucket handle’ in the inner surface of the dialysis, especially in traumatic cases. Blunt trauma has been associated with dialysis formation, but a history of trauma is not always present, and some are thought to be spontaneous (Kinyoun and Knobloch 1984). In the latter, a familial basis has been sought but remains uncertain (Verdaguer et al. 1975; Ross 1991). On rare occasions, a retinal dialysis is seen a few days after a severe contusion injury in which case the dialysis and retina are mobile.

The commonest sites are inferotemporal and superonasal. Fifty-six percent of inferotemporal dialyses have been associated with trauma and the 87 % of superonasal dialyses (Zion and Burton 1980). Fourteen percent are bilateral in

Fig. 7.1 A retinal dialysis is seen by indirect ophthalmoscopy and indentation

Fig. 7.2 A retinal dialysis

Clinical features in RRD from retinal dialysis