Insight into small eyes: a practical description from phenotypes presentations to the management

This narrative review aimed to have an algorithmic approach to microphthalmos by a systematic search.The definition can be related to a number of special phenotypes.In the more challenging cases of complex microphthalmos,relative anterior microphthalmos,and nanophthalmos,the surgeon can approach these cases more safely if they have a deep understanding of the anatomical variations and ideal formulae for intraocular lens computation and knows how to avoid intra-and post-operative complications.In this article,we review the criteria by which we recognize and describe pre-,intra-,and post-operative considerations,as well as discuss the ideal intraocular lenses for microphthalmos,given the intricate varieties of small eye phenotypes.

Three Novel Mutations of Microphthalmos Identified in Two Chinese Families

Genetic alterations are a major cause of microphthalmos,while novel-related genes and mutations in microphthalmos have rarely been explored.To identify the underlying genetic defect responsible for microphthalmos eyes in two three-generation Chinese families,we screened 425 genes involved in common inherited non-syndromic eye diseases with next-generation sequencing-based target capture sequencing of the two probands of two three-generation Chinese families diagnosed with microphthalmos.Variants were filtered and analyzed to identify possible disease-causing variants before Sanger sequencing validation.We enrolled two families with microphthalmos(Family 1:microphthalmos with congenital ocular coloboma and Family 2:simple microphthalmos).Two novel heterozygous mutations,Peroxidasin(PXDN)c.3165C>T(p.Pro1055Pro)and PXDN c.2640C>G(p.Arg880Arg),were found in Family 1,and Crystallin Beta B2(CRYBB2)c.481G>A(p.Gly161Arg)was found in Family 2,but none of the mutations were found in the unaffected individuals,who were phenotypically nor-mal.Multiple orthologous sequence alignment(MSA)revealed that the CRYBB2 p.Gly161Arg mutation was a deleterious effect mutation.In conclusion,the three novel mutations found in our study extend our current understanding of the genetic basis of microphthalmos and provide early pre-symptomatic diagnosis and emphasize the significance of genetic diagnosis of microphthalmos.

Clinical features of posterior microphthalmic and nanophthalmic eyes

AIM： To clinically differentiate nanophthalmos（NO） and posterior microphthalmos（PM） and to explore the mechanisms related to papillomacular folds（PMF）.METHODS： Medical records of 34 unrelated patients with microphthalmos（54 eyes） from April 2009 to October 2017 were retrospectively reviewed.RESULTS： Fourteen eyes of 7 unrelated patients with NO and PM were included in the study. The presenting age of the NO cohort was significantly higher compared with the PM cohort（NO： 27±16 y; PM： 3.7±0.6 y）. PMF was more likely to occur in cases with PM than in NO（25% in NO, 100% in PM）. The anatomic features of PMF from optical coherence tomography（OCT） included： ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer and outer nuclear layer. In eyes without an apparent PMF（these were all NO eyes）, rudimentary fovea without a foveal pit was noted. Four eyes that were NO developed angle closure glaucoma. Three NO eyes developed exudative retinal detachment and were successfully treated with lamellar sclerectomy.CONCLUSION： Posterior segment changes are pervasive both in PM and NO. Complications like angle closure glaucoma and exudative retinal detachment are likely to occur in eyes with NO but not with PM. Detailed OCT analysis found that PMF was partially a neural retinal issue, suggesting that redundancy of retinal issues involved only inner retinal layers.