choroidal effusion

Nanophthalmos 2

Clinical Characteristics
Ocular Features: 

In this condition the axial length of the globe is often only 14-16 mm (normal >20 mm) resulting in extreme hyperopia of +8-25 diopters.  Corrected vision is usually 20/40 to 20/80 but 20/200 is not uncommon.  The choroid and sclera are thickened in nanophthalmos to a greater degree than seen in common mild hyperopia.  While all ocular structures are small in microphthalmia, in nanophthalmos the lens dimensions are generally normal.  In a small globe this causes ‘crowding’ of the anterior chamber angles and angle closure glaucoma is a major risk.

Folds in the choroid and retina are common.  Choroidal effusions, retinal edema and retinal detachments are not uncommon.  The retinal pigment epithelial may have mild window defects.  Hypoplasia, cysts, yellowish discoloration, and horizontal striae of the macula have been reported.  The foveal reflex is frequently absent corresponding to the lack of a normal foveal pit as revealed by OCT.  The foveal avascular zone may be small or absent.  The disks often appear crowded.  ERGs and VEPs are usually normal.   Scleral collagen is abnormal and thickened, leading to the postulation that this interferes with suprachoroidal drainage resulting in effusion and non-rhegmatogenous retinal detachments.

Systemic Features: 

No systemic disease has been consistently associated with simple nanophthalmos. Individuals with Kenny’s syndrome, Hallerman-Streiff-Francois (234100) syndrome and oculodentodigital dysplasia syndrome (164200) with nanophthalmos have been reported.


Nanophthalmos may result from several mutations. Most cases occur sporadically but familial cases suggesting autosomal recessive inheritance (NNO2, 609549) have been reported. The mutation is a frameshift insertion, 1143C, in the MFRP gene on chromosome 11 (11q23.3) and has been found in the homozygous configuration in several families. The protein product has a domain that may be related to the Frizzled family of transmembrane  cell-cell signaling molecules responsible for regulation of growth and differentiation. In this connection, it is of interest that this gene is highly expressed in the retinal pigment epithelium.

It seems that at least two dominant mutations can also cause nanophthalmos. One (NNO3, 611897), located on chromosome 2 (2q11-q14), has been identified in a large Chinese pedigree although the molecular mutation remains unknown. Another, NNO1, (600165), has also been mapped to chromosome 11 but at 11p.  The molecular mutations also remain unknown.

Homozygous mutations in serine protease PR2258 have also been reported in several families with nanophthalmos.

Autosomal dominant
Autosomal recessive
Treatment Options: 

Prophylactic iridotomies should be considered.

Article Title: 

Familial nanophthalmos

Cross HE, Yoder F. Familial nanophthalmos. Am J Ophthalmol. 1976 81(3):300-6.

PubMed ID: 

The nanophthalmic macula

Serrano JC, Hodgkins PR, Taylor DS, Gole GA, Kriss A. The nanophthalmic macula. Br J Ophthalmol. 1998 Mar;82(3):276-9.

PubMed ID: 

Mutations in a novel serine protease PRSS56 in families with nanophthalmos

Orr A, Dub?(c) MP, Zenteno JC, Jiang H, Asselin G, Evans SC, Caqueret A, Lakosha H, Letourneau L, Marcadier J, Matsuoka M, Macgillivray C, Nightingale M, Papillon-Cavanagh S, Perry S, Provost S, Ludman M, Guernsey DL, Samuels ME. Mutations in a novel serine protease PRSS56 in families with nanophthalmos. Mol Vis. 2011;17:1850-61.  PubMed PMID: 21850159.

PubMed ID: 
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