Developmental Basis of Nanophthalmos:MFRPIs Required for both Prenatal Ocular Growth and Postnatal Emmetropization

Abstract

Background-Nanophthalmos is a genetic disorder characterized by very small, hyperopic eyes that are without gross structural defects. Recessive nanophthalmos is caused by severe mutations in the MFRP gene, which encodes a Frizzled-related transmembrane protein that is selectively expressed in the retinal pigment epithelium (RPE) and ciliary body.

A 61-year-old man with cystoid macular edema and chorioretinal folds after cataract surgery

“…7 Other characteristics include severe hyperopia, increased retinal-choroidal-scleral thickness, a crowded anterior chamber, and chorioretinal folds. 5,6,8,9 The crowded anterior chamber of nanophthalmos is of particular concern, because it predisposes the patient to acute angle-closure glaucoma. 10 Additional complications arise from a thick scleral collagen, which can result in choroidal effusion, retinal detachment, and cystoid macular edema.…”

“…Nanophthalmos is a rare condition; a preliminary diagnosis can be made with a measurement of axial length <21 mm. 6 Presentation is normally bilateral, and patients can have slight enophthalmos and narrow palpebral fissures. 7 Other characteristics include severe hyperopia, increased retinal-choroidal-scleral thickness, a crowded anterior chamber, and chorioretinal folds.…”

“…The MFRP protein is expressed in the retinal pigment epithelium and ciliary body and is important to later stages of ocular development. 6,7 It is thought that mutations in MFRP result in decreased ocular growth, leading to crowding and thickening of the retina and choroid, abnormal foveal development, and chorioretinal folds. [6][7][8]12 A gene TMEM98 (transmembrane protein 98) on chromosome 17 has also recently been implicated in a form of AD nanophthalmos.…”

“…6,7 It is thought that mutations in MFRP result in decreased ocular growth, leading to crowding and thickening of the retina and choroid, abnormal foveal development, and chorioretinal folds. [6][7][8]12 A gene TMEM98 (transmembrane protein 98) on chromosome 17 has also recently been implicated in a form of AD nanophthalmos. 13,14 Nanophthalmos can additionally be present in less common conditions such as oculo-dento-digital and Kenney-Caffey syndromes.…”

Contact lenses for visual rehabilitation in Bilateral Nanophthalmos with Retinal Dystrophy- A case report

“…Introduction Nanophthalmos is a rare bilateral genetic disease, included in the spectrum of developmental eye disorders, characterized by a small eye secondary to compromised growth (Sundin OH et al, 2008). Nanophthalmos is derived from the Greek word nano, meaning dwarf, and nanophthalmic eyes typically present very high to extreme axial hyperopia without other obvious structural defects (O'Grady RB, 1971;Cross & Yoder, 1976).…”