• 1 AbnormalitiesSECTION Congenital
Mittendorf Dot
Key Facts
•Remnant of the anterior end of the hyaloid vessel at posterior lens apex
•Sometimes associated with posterior lenticonus
Clinical Findings
• A grey-white dot opacity axial or nasal paraxial to lens posterior pole
Ancillary Testing
• None
Differential Diagnosis
•Posterior polar cataract
•Persistent hyperplastic primary vitreous
•Congenital cataract
Treatment
• Non-progressive, almost never requires surgery
Prognosis
• Visually insignificant
Fig. 1.8 A coincidental finding on routine eye examination, this Mittendorf dot was of no visual consequence (pictured here 180º away from the camera’s light reflex). It is typically found just nasal to center.
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Fig. 1.9 A more dramatic example of Mittendorf dot in a 6-year-old girl (the persistent anterior hyaloid vasculature is shown in Fig. 1.10). The small posterior lens opacity, the once anterior hyaloid vessel attachment to the posterior lens capsule, is not an uncommon finding in routine eye examinations.
Fig. 1.10 The persistent anterior hyaloid vessel attachment at the posterior lens apex. A dramatic illustration of the anterior hyaloid vascular remnant attached to the posterior lens capsule.
Dot Mittendorf
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Section 2 |
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Developmental Defects |
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Marfan Syndrome |
10 |
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Homocystinuria |
12 |
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Ectopia Lentis |
14 |
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Simple Ectopia Lentis |
16 |
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Ectopia Lentis et Pupillae |
18 |
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Weill–Marchesani Syndrome |
20 |
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Persistent Fetal Vasculature |
22 |
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• 2 SECTIONDefects Developmental
Marfan Syndrome
Key Facts
•Autosomal dominant (4–6/100 000)
•Mutation of fibrillin gene FBN1 on chromosome 15
•Systemic features:
•tall • long limbs • arachnodactyly • flexible joints • pectus excavatum
•high-arched palate • aortic dilation, valvular insufficiency, and dissection, and mitral valve prolapse
Clinical Findings
•Axial myopia, astigmatism
•Lens:
•bilateral • superotemporal (two-thirds of cases) • lens subluxation (50–80%) or dislocation
•Zonules usually intact
•Cornea:
•increased diameter • flatter
•Thin, blue sclera
•Glaucoma or angle anomaly
•Iris:
•smooth, velvety appearance (lacks circumferential ridges, furrows, and crypts)
•iridodonesis • transillumination (hypopigmentation of posterior iris pigment epithelium) • miotic (dilator muscle hypoplasia) • can be eccentric
•Cataract
•Lattice retinal degeneration, tears, and detachments
Ancillary Testing
•Keratometry (astigmatism mainly corneal)
•Biometry (long axial length measurements)
•Cardiac evaluation necessary
•Genetic counseling
•Work-up for aortic pathology
Differential Diagnosis
•Homocystinuria • Weill–Marchesani syndrome • Ehlers-Danlos syndrome • Sulfite oxidase deficiency • Hyperlysinemia • Congenital syphilis • Crouzon syndrome • Trauma • Ectopia lentis • Congenital
glaucoma • Retinitis pigmentosa • Rieger syndrome • Medulloepithelioma
Treatment
•Initially, optimize refractive correction optically
•Consider optical iridectomy
•Lensectomy
• Consider capsular tension rings, sulcus fixation, or sutured intraocular lenses
Prognosis
•Intraoperative complications can be high, although this is improving with newer endocapsular techniques
•Good surgical results can be limited by amblyopia
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Fig. 2.1 Lenticular subluxation in a Marfan syndrome patient.
Syndrome Marfan
Fig. 2.2 Superior lens subluxation in a Marfan syndrome patient. The capsular lens zonules remain intact for the most part.
Fig. 2.3 Retroillumination highlights the stretched but mostly intact zonules.
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