LAUSR

Complete microphthalmos, also known as nanophthalmos, is a rare developmental ocular anomaly that is characterized by short axial length (≤20 mm), microcornea, high hypermetropia (+8D to +25D), relative anterior or posterior microphthalmos, and global reduction in ocular volume.[1] It is usually a bilateral symmetrical condition with high corneal curvature, high lens/eye volume ratio, narrow anterior chamber angle, and thickened sclera. The clinical appearance is small sunken deep, set eyes (relative enophthalmos), and narrow palpebral fissure height; occasionally, mild ptosis can be present.[2] The majority of cases are sporadic. Autosomal dominant and recessive modes have also been reported in the literature. NNO1 and NNO3 genetic loci are associated with autosomal dominant non‐syndromic nanophthalmos, and NNO2 is associated with autosomal recessive non‐syndromic nanophthalmos.[3] Nanophthalmos can present as an isolated entity or spectrum of various syndromes such as oculo‐dento‐digital (ODD) syndrome, foveoschisis, retinitis pigmentosa, optic drusen syndrome, Kenny–Caffey syndrome, and autosomal dominant vitreoretinochoroidopathy with nanophthalmos (ADVIRC).[4] Children with nanophthalmos are at high risk of developing strabismus, amblyopia, angle‐closure glaucoma, retinal detachment, choroidal detachment, and uveal effusion syndrome. Various posterior segment pathologies such as cystoid macular edema, retinal and choroidal folds, crowded optic disc, sclerochoroidal thickening, and pigmentary retinal dystrophy have also been reported with nanophthalmos. In nanophthalmos, there is growth arrest due to rearrangement of scleral collagen and may not be associated with structural eye defects. The diagnosis in these cases is based on meticulous anterior and posterior segment examination, cycloplegic retinoscopy, applanation tonometry, gonioscopy, keratometry, A‐scan, structural analysis of optic nerve head, B‐scan, ultrasound biomicroscopy (UBM), and visual evoked potential (VEP) in required cases. The management options available are spectacles, strabismus surgery for non‐refractive esotropia, laser peripheral iridectomy for angle closure, filtration surgery, and cataract surgery. Nanophthalmos management is still a therapeutic challenge for clinicians; thus, prompt diagnosis and meticulous management are warranted in each case to safeguard vision and prevent irreversible complications. The clinical and biometric parameters of nanophthalmos in children are less well understood, and the clinical features may overlap with relative anterior microphthalmos and simple, partial, complex, and posterior microphthalmos. There is limited literature available on pediatric nanophthalmos. Recently, some studies have offered promising insights into the clinical, morphological, biometric features, and management aspects.