Fig. 14.23 See previous Þgure

14.3.2 Types of Retinal Break

14.3.2.1 Dialysis

In blunt trauma, the commonest break is an inferotemporal dialysis then superonasal (see Chap. 6), which because of the slow onset of detachment may not become symptomatic until months or years after the injury when the macula detaches. Occasionally, an avulsion of the vitreous base is seen comprising a strip of ciliary epithelium, ora serrata and immediately post-oral retina into which the basal vitreous gel remains inserted. This Ôbucket handle,Õ often in the supranasal quadrant, hangs down in the vitreous cavity. The free posterior edge of

torn retina becomes detached. Beware that some patients can present with giant dialysis (90Ð360¡) in contusion injuries.

14.3.2.2 Pars Ciliaris Tears

In a few cases, retinal tears may be found in the non-pig- mented epithelium of the pars ciliaris, therefore difÞcult to detect, typically causing a slow-onset shallow retinal detachment (Alappatt and Hutchins 1998). This should be considered in children with a poor history and a chronic RRD.

14.3.2.3 Ragged Tear in Commotio Retinae

In severe injury, the choroid and retina have an ischaemic and haemorrhagic appearance (sclopetaria) and can produce a ragged degenerative break that may be large. This should be treated by observation at Þrst, but these can cause retinal detachment and be associated with vitreous haemorrhage when intervention is indicated (Martin et al. 1994).

14.3.2.4 Giant Retinal Tears

Occasionally, posterior-vitreous-detachment-related tears can be seen most classically giant retinal tears but occasionally U tears.

Note: In contusion injury, it is often possible to wait and see what develops.

Fig. 14.25 This patient who suffered macular oedema from a severe blunt trauma also produced a macular hole

Fig. 14.26 Choroidal ruptures occur in blunt trauma and are seen as circumferential white lines. In this case, one is very close to the fovea. These patients can produce type II choroidal neovascular membranes from these defects

Fig. 14.27 A long choroidal rupture from contusion injury caused by a Þst hitting the eye during an assault. Notice associated macular wrinkling

Fig. 14.28 The shock wave from a high-velocity projectile is enough to disrupt the structure of the retina