• Clinical condition characterized by an abnormal funduscopic appearance of the macula and decrease or absence of the foveal reflex and varying degrees of macular hypoplasia
• Macular vessels often traverse near or across the normally avascular zone of the fovea.
• Optic nerves and peripheral retina may appear normal.
• Visual acuity typically in the 20/100–20/200 range but variable depending on degree of hypoplasia
• Commonly associated with albinism and aniridia
• Family history
• When seen in combination with aniridia or albinism the genetics of those syndromes apply. Also reported with Axenfeld–Reiger spectrum.
• Isolated autosomal dominant macular hypoplasia may be due to mutations in PAX6 (11p13).
• Autosomal recessive inheritance also reported including foveal hypoplasia with anterior segment dysgenesis (FHASD, 16q23.2–24.2).
Genetic counseling and/or prenatal testing (if mutated gene known or syndrome recognized in family).
• Results from incomplete development of the fovea.
• In albinism, the absence of melanin in the retinal pigmented epithelium leads to a failure of induction of proper macular development
• In aniridia or isolated macular hypoplasia due to PAX6 mutation it is presumed that there is a failure of induction of a gene(s) downstream from PAX6, responsible for macular differentiation.
Thought to result from incomplete embryologic development of the fovea, which typically develops in stages:
• Stage 1: Indistinct pigmented area
• Stages 2 and 3: Development of the annular reflex
• Stage 4: Appearance of the foveal pit
• Stage 5: Development of the foveal reflex
COMMONLY ASSOCIATED CONDITIONS
• Less common: Axenfeld–Reiger
• Reduced vision
Poor vision, possible nystagmus.
• Full ocular examination including careful evaluation of the macula
• Careful examination with indirect ophthalmoscope by noting presence or absence of annular ring and foveal light reflex and anomalous patterns of macular vessels
• Assess vision, nystagmus
DIAGNOSTIC TESTS & INTERPRETATION
Initial lab tests
Follow-up & special considerations
Consider molecular genetic testing where appropriate.
• OCT can be used for grading.
– Widespread thickening of the retina throughout the entire fovea with no difference in thickness from the surrounding macula
– High reflectivity of the inner retina
Visual field, especially Goldmann, may be helpful.
• Absence of foveal differentiation and red-free zone
• Continuation of ganglion cell layer throughout macula
• Associated with reduction in the thickness of the optic nerve and in the volume of gray matter in the visual cortex
• Abnormalities in the length and mean surface area of the calcarine fissure present in visual cortex
• Epiretinal membrane
• Macular drag (e.g., retinopathy of prematurity, familial exudative retinopathy)
• High myopia
• Blonde fundus
• Congenitally anomalous retinal vascular (e.g., macrovessel, tortuosity)
• Optic atrophy with secondary macular nerve fiber loss
• Optic nerve hypoplasia
• Retinal/macular dystrophy
• Amblyopia therapy as indicated
• Genetic counseling
• If photophobia consider Corning lenses
Issues for Referral
• Genetic counseling/ocular genetics
• Low vision
Maximization of vision potential with spectacles, contact lenses, and/or low-vision aids.
COMPLEMENTARY & ALTERNATIVE THERAPIES
None proven or indicated.
• None for foveal hypoplasia
• Strabismus and nystagmus surgery as indicated (nystagmus surgery unlikely to yield great visual acuity improvement)
• As needed for amblyopia and strabismus monitoring and treatment
– Low-vision evaluation
• Monitor patients for associated conditions of aniridia and albinism and congenital nystagmus
• Visual development and function
• If asymmetric, amblyopia can occur.
• Visual prognosis based on associated conditions and degree of macular hypoplasia
• Presence of anomalous blood vessels in macula (e.g., crossing midline raphe, extending close or through putative fovea) associated with worse visual prognosis
Low vision, nystagmus, amblyopia, strabismus.
• Brodsky MC, Baker RS, Hamed LM. “Pediatric Neuro-Ophthalmology”, 2nd ed. Springer: New York, New York, 1996:304–307,314.
• Schroeder HW, et al. Hereditary foveal hypoplasia. Klin Monbl Augenheikd 2003;220(8):559–562.
• Holmstrom G, et al. Optical coherence tomography is helpful in the diagnosis of foveal hypoplasia. Acta Ophthalmol 2010;88(4):439–442.
• Mietz H, et al. Foveal hypoplasia in complete oculocutaneous albinism. A histopathologic study. Retina 1992;12(3):254–260.
• Huynh SC, et al. Macular and nerve fiber layer thickness in amblyopia: the Sydney Childhood Eye Study. Ophthalmology 2009;116(9):1604–1609.
362.89 Other retinal disorders
• Look for this condition in patients with significant subnormal vision and without nystagmus.
• Look closely for this condition in patients who do not respond as expected to amblyopia therapy.