17.5 Retinochoroidal Coloboma

Some patients may be suffering from renal coloboma syndrome with renal hypoplasia and a mutation of the PAX2 gene, and therefore renal investigations may be advisable (Ttie-Bitach et al. 2001).

17.4.2 Morning Glory Syndrome

This severe optic disc anomaly can be associated with posterior polar retinal detachment in as many as 35 % of patients (Haik et al. 1984). Often vision is poor because of the disc abnormality. A communication has been described between the subarachnoid space (Chang et al. 1984) and the subretinal space (metrizamide cisterography has shown dye migration into the SRF). Patients have been treated by optic nerve sheath fenestration, where a window of dura is removed from the optic nerve, with resolution of the RD (Irvine et al. 1986). More commonly a hole on the optic nerve head has been blamed for the passage of fluid from the vitreous cavity to the subretinal space. For this reason vitrectomy has been used with peripapillary laser applied to block the flow of fluid and with internal tamponade. Such a communication has been demonstrated by the complication of subretinal oil or gas occurring postoperatively in these cases (Coll et al. 1995).

Fig. 17.36 Retinal adhesion from laser photocoagulation to prevent spread of SRF can be employed in selected cases. This can only be used successfully in eyes in which there is very gradual fluid accumulation (tiny break or formed attached vitreous) or little momentum in the SRF to lift the adherent edge (shallow SRF or low volume of SRF). It has been used successfully in this patient with CHARGE who has a shallow ‘blister’ of SRF leaking under the retina on the edge of the coloboma, thereby avoiding more invasive surgery in this complex case

17.5Retinochoroidal Coloboma

Congenital coloboma of the posterior pole can result in rhegmatogenous retinal detachment from breaks on the edge of the defect (Steahly 1990), in the coloboma (Corcostegui et al. 1992) or in the peripheral retina (Gopal et al. 1991, 1995). For breaks in the coloboma, laser should be applied to the edge of the coloboma, but take care if the laser must be applied to the disc margin as visual loss can occur (McDonald et al. 1991). Internal tamponade with or without a scleral buckle can be used. Cyanoacrylate retinopexy has been used to seal breaks in the coloboma (Hotta et al. 1998).

Fig. 17.37 A droplet of oil (arrow) can be seen under the retina in the coloboma, suggesting a communication from the vitreous cavity and the subretinal space postoperatively

Fig. 17.38 A morning glory disc is shown which can be associated with retinal detachment

Fig. 17.43 Optic disc anomalies associated with retinal detachment have been shown to develop subretinal oil or gas, possibly through communication through the optic disc. Subretinal oil was demonstrated in this patient with an optic disc anomaly

Fig. 17.44 A retinal detachment in a patient with retinochoroidal coloboma in this case with a tear between the coloboma and the ora serrata which responded to PPV and inferior indent

17.6Marfan’s Syndrome

Marfan’s syndrome is a connective tissue disorder which affects the skeleton, lungs, eyes, heart and blood vessels. The disease is characterised by unusually long limbs (arm span longer than the patient’s height) and long fingers, especially the middle phalanx. Marfan’s syndrome is an autosomal dominant disorder and has been linked to the FBN1 gene on chromosome 15; this encodes a protein called fibrillin, essential for the formation of elastic fibres.

These patients present in two ways with ocular problems, with dislocated or subluxated crystalline lenses or with RRD associated with their high myopia. Bilaterality of RRD is high at 70 % (Abboud 1998) with tears varying from small breaks to giant retinal tears (Dotrelova et al. 1997). Dislocated lenses can be observed until these become problematic with the edge of the lens interfering with the visual axis. The lenses usually

Fig. 17.47 This patient with Marfan’s syndrome has a dislocated lens which has entered the anterior, chamber causing pupil block glaucoma; the iris is behind the equator of the lens. Lying the patient prone and massaging the eye allowed the lens to drop into the posterior segment with later PPV and removal of the lens

Fig. 17.45 A crystalline lens has dislocated into the posterior segment. A demarcation between the dense nuclear sclerosis and a clearer cortical lens material can be seen with some residual zonular fibres

require removal by vitreolensectomy (Hubbard et al. 1998) often at a young age. Lens implantation is problematic in that sutured sulcus lenses are prone to problems such as suture erosion, vitreous haemorrhage, lens tilt and dislocation in the long term (Bading et al. 2007; Johnston et al. 2000). Therefore, leaving the eye aphakic may be appropriate with contact lens usage. Fully dislocated lenses may be left in situ if asymptomatic, but there is a risk of lens-induced uveitis or glaucoma (Abourizk et al. 1980) or lens dislocation into the anterior chamber.