DISEASE
Tilted disc syndrome (TDS), also known as Fuchs Coloboma, is a congenital anomaly that occurs in 1 to 2% of the population.
While mostly understood as a nonhereditary process, reports of autosomal dominant inheritance exist. It is characterized by inferonasal tilting of the optic disc and most commonly occurs bilaterally.
Tilted disc syndrome also has an association with high myopia as one-fifth of patients with greater than 5 diopters of myopia have tilted discs.
Bitemporal superior visual field defects are present in about one-fifth of patients with tilted discs and other features of TDS include inferior or inferonasal crescent, the irregular orientation of retinal vessels (situs inversus), and ectasia of the lower fundus or inferior staphyloma.
Tilted disc syndrome is thought to be caused by oblique insertion of the optic nerve and retinal vessels due to incomplete closure of the embryonic fissure of the eye.
Additionally, there is hypoplasia and thinning of the retinal, choroidal, and scleral layers with focal hypopigmentation and ectasia of the inferonasal posterior wall of the globe.
It is unclear whether both the disc anomalies and inferior staphylomas co-exist at birth or whether the inferior staphyloma deepens with time.
Complications
There are various macular complications described in TDS in the literature. These include retinal pigment epithelium (RPE) atrophy, choroidal neovascular membrane (CNVM), subretinal fluid (SRF), polypoidal choroidal vasculopathy (PCV), fovea plana, foveoschisis, and lamellar macular hole (LMH).
Choroidal mechanical and hemodynamic changes at the upper edge of the staphyloma have been proposed to explain the pathophysiology of these complications.
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Photograph the retinal findings described here with the phone already in your pocket — 22 D optics and built-in illumination in one handheld unit.
From Choroida — the team behind this siteREFERENCES
1. Willams, A, et al. The tilted disc syndrome. Practical Neurology, 2005, 5, 54-55
2. Bottoni FG, et al. Dominant inherited tilted disc syndrome and lacquer cracks. Eye (1990), 4, 504-9
3. Manfre L, Vero S, Focarelli-Barone C, Lagall R. Bitemporal Pseudohemianopia related to the “Tilted Disk” Syndrome: CT, MR, and Fundoscopic Findings. AJNR Am J Neuroradiol 20:1750-1751, October 1999
4. Vuori ML Mantyjarvi M. Tilted disc syndrome may mimic false visual field deterioration. Acta Ophthalmol. 2008 Sep;86(6):622-5.
5. Rucker CW (1944) Bitemporal defects in the visual fields resulting from developmental anomalies of the optic discs. Archives of Ophthalmology, 32, 56-9.
Test yourself
A few questions straight from this article.
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What proportion of the population is affected by tilted disc syndrome?
Tilted disc syndrome is a congenital anomaly that occurs in 1 to 2% of the population. -
In which direction is the optic disc characteristically tilted in tilted disc syndrome?
The syndrome is characterised by inferonasal tilting of the optic disc; an inferior or inferonasal crescent is another listed feature. -
How does tilted disc syndrome most commonly present in terms of laterality?
Tilted disc syndrome is a congenital anomaly that most commonly occurs bilaterally. -
What proportion of patients with more than 5 dioptres of myopia have tilted discs?
Tilted disc syndrome is associated with high myopia: one-fifth of patients with more than 5 dioptres of myopia have tilted discs. -
Which visual field defect is present in about one-fifth of patients with tilted discs?
Bitemporal superior visual field defects are found in about one-fifth of patients with tilted discs. -
Which retinal vessel abnormality is a recognised feature of tilted disc syndrome?
Irregular orientation of the retinal vessels (situs inversus) is one of the listed features, along with the inferior crescent and inferior staphyloma. -
What is tilted disc syndrome thought to result from?
It is thought to arise from oblique insertion of the optic nerve and retinal vessels caused by incomplete closure of the embryonic fissure. -
What is known about the inheritance of tilted disc syndrome?
Tilted disc syndrome is mostly understood as a nonhereditary process, although reports of autosomal dominant inheritance exist. -
Which macular complication has been described in tilted disc syndrome?
Described macular complications include CNVM, RPE atrophy, subretinal fluid, polypoidal choroidal vasculopathy, foveoschisis and lamellar macular hole. -
In tilted disc syndrome, where are choroidal changes proposed to drive macular complications?
Mechanical and haemodynamic choroidal changes at the upper edge of the inferior staphyloma have been proposed to explain these macular complications.
