![]() Secondary angle closure glaucoma is the most common sight threatening complication of microspherophakia. Glaucoma is common in microspherophakia and has been reported in up to 51% of patients. Microspherophakia with minimal to mild lens subluxation Photo courtesy - LVPEI Bhubaneswar Screening tests may be required for associated systemic conditions like serum homocysteine levels and urine screening test for homocysteinuria. It provide morphological details of anterior chamber angle, iris, ciliary body, zonules & lens and is specially useful in challenging cases like those having small and fixed pupil. This imaging technology uses ultrasonic waves to produce two dimensional cross sectional images of the anterior segment. UBM ( ultrasound biomicroscopy) might be useful in diagnosis of microspherophakia. Signs associated with complications like ectopia lentis, glaucoma, high myopia, retinal detachment, etc.Posterior staphyloma, myopic crescent, ectopic pupil, or blue sclera.Entire equatorial margin of the lens is seen with full mydriasis which will move with change in posture.Thick crystalline lens with smaller diameter and defective accommodation.Patients might present with diminution of vision or acute eye pain.Ĭlassically, signs of microspherophakia include the triad of angle closure glaucoma, shallow anterior chamber, and refractive myopia. Zonular instability might lead to lens dislocation/ subluxation or secondary angle closure glaucoma. Zonular fibers may also be rudimentary due to lack of tension and arrest in lens development so that it may remain spherical instead of gradually converting to a normal biconvex shapeĪ thorough family history and history of systemic anomalies is required.Arrest in development or abnormal insertion of secondary lens fibers both of which may be secondary to a nutritional deficiency from defects in tunica vasculosa lentis and may occur in the fifth and sixth month of embryonic life as the lens is normally spherical at this stage.Later on hyaloid degenerations are noted due to changes in shape of lens affecting the lens fibers.įollowing mechanisms has been suggested : In addition there may be abnormal development and distribution of secondary lens fibers. In histopathological study it has been found that zonular fibers may be abnormally long and somewhat rudimentary. Pattern of inheritance is mainly autosomal recessive, but it can also be autosomal dominant. Rhizomelic form of Chondrodysplasia punctataįamilial microspherophakia is not associated with systemic abnormalities. Microspherophakia may occur as an isolated defect, may be familial or it might be associated with systemic / local anomalies as follows:Įntities associated with microspherophakia It might have a role in regulation of elastic fibre assembly.ĪDAMTS17 is part of same family of metalloproteinases as ADAMTS10 which is the main gene associated with Weill-Marchesani syndrome. LTBPs are a family of proteins showing structural homologies with fibrillins and is expressed in trabecular meshwork, ciliary processes and lens capsule/epithelium layer. ![]() Latent TGF β-binding protein-2 (LTBP2) gene.Mutations in following genes have been noted: May be associated with lens dislocation/ subluxation, high myopia, defective accommodation, glaucoma.Movement of lens with change in posture.Equator of the lens is visible with full mydriasis.Increased anteroposterior diameter of the lens.Studies in families with ectopia lentis et papillae have revealed that as many as 50% of individuals with dislocated lenses do not have ectopic pupils.Microspherophakia has the following characteristics: Prominent iris processes into the anterior chamber angle have been reported and glaucoma, both acute and chronic, is sometimes seen. Visual acuity is highly variable, ranging from 20/20 to light perception depending upon the density of cataracts which often develop at a relatively young age. The lens displacement can progress and cataracts seem to form at a relatively young age. The lens is often malformed and in some cases frankly microspherophakic. The iris may transilluminate (67%) and the pupils dilate poorly. However, other abnormalities are often present such as persistent pupillary membrane (87%), iridohyaloid adhesions, increased corneal thickness, enlarged corneal diameters, and axial myopia. This disorder is generally considered to consist of simple displacement of the pupil and dislocation of the lens (usually in opposite directions).
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