To the Editor:
In their otherwise excellent article, Sundin et al.Citation1 erroneously state that the term “posterior microphthalmia” is synonymous with nanophthalmos. Although both conditions are characterized by shortened axial lengths and high hyperopia, in nanophthalmos anterior chamber dimensions are decreasedCitation1,Citation2 whereas in posterior microphthalmos the anterior segment is of normal (or slightly subnormal) size.Citation3,Citation4,Citation5 Thus the phenotype of posterior microphthalmos does not include the predisposition to angle-closure glaucoma that is part of nanophthalmos phenotype.Citation3,Citation4,Citation5 Additional findings of posterior microphthalmos include retinal folds, occasional pigmentary retinopathy, and a propensity for uveal effusion.Citation3,Citation4,Citation5 Published reports and my own experience suggest that posterior microphthalmos is a distinct autosomal recessive isolated ocular phenotype.Citation3,Citation4,Citation5
REFERENCES
- Sundin O H, Dharmaraj S, Bhutto I A, Hasegawa T, McLeod D S, Merges C A, et al. Developmental basis of nanophthalmos: MFRP is required for both prenatal ocular growth and postnatal emmetropization. Ophthalmic Genet. 2008; 29: 1–9
- Othman M I, Sullivan S A, Skuta G L, Cockrell D A, Stringham H M, Downs C A, Fornés A, Mick A, Boehnke M, Vollrath D, Richards J E. Autosomal dominant nanophthalmos (NNO1) with high hyperopia and angle–closure glaucoma maps to chromosome. Am J Hum Genet. 1998; 63: 1411–1418
- Khan A O. Recognizing posterior microphthalmos. Ophthalmology. 2006; 113: 718
- Spitznas M, Gerke E, Bateman J B. Hereditary posterior microphthalmos with papillomacular fold and high hyperopia. Arch Ophthalmol. 1983; 101: 413–417
- Khairallah M, Messaoud R, Zaouali S, Ben Yahia S, Ladjimi A, Jenzri S. Posterior segment changes associated with posterior microphthalmos. Ophthalmology. 2002; 109: 569–574