JAMA Ophthalmology: Ophthalmology Topic Collection

Outer Retinal Structure in Best Vitelliform Macular Dystrophy Best Vitelliform Macular Dystrophy

Kay DB, Land ME, Cooper RF, et al. — Thu, 13 Jun 2013 00:00:00 GMT

Importance

Demonstrating the utility of adaptive optics scanning light ophthalmoscopy (AOSLO) to assess outer retinal structure in Best vitelliform macular dystrophy (BVMD).

Objective

To characterize outer retinal structure in BVMD using spectral-domain optical coherence tomography (SD-OCT) and AOSLO.

Design, Setting, and Participants

Prospective, observational case series. Four symptomatic members of a family with BVMD with known BEST1 mutation were recruited at the Advanced Ocular Imaging Program research lab at the Medical College of Wisconsin Eye Institute, Milwaukee.

Intervention

Thickness of 2 outer retinal layers corresponding to photoreceptor inner and outer segments was measured using SD-OCT. Photoreceptor mosaic AOSLO images within and around visible lesions were obtained, and cone density was assessed in 2 subjects.

Main Outcome and Measure

Photoreceptor structure.

Results

Each subject was at a different stage of BVMD, with photoreceptor disruption evident by AOSLO at all stages. When comparing SD-OCT and AOSLO images from the same location, AOSLO images allowed for direct assessment of photoreceptor structure. A variable degree of retained photoreceptors was seen within all lesions. The photoreceptor mosaic immediately adjacent to visible lesions appeared contiguous and was of normal density. Fine hyperreflective structures were visualized by AOSLO, and their anatomical orientation and size were consistent with Henle fibers.

Conclusions and Relevance

The AOSLO findings indicate that substantial photoreceptor structure persists within active lesions, accounting for good visual acuity in these patients. Despite previous reports of diffuse photoreceptor outer segment abnormalities in BVMD, our data reveal normal photoreceptor structure in areas adjacent to clinical lesions. This study demonstrates the utility of AOSLO for understanding the spectrum of cellular changes that occur in inherited degenerations such as BVMD. Photoreceptors are often significantly affected at various stages of inherited degenerations, and these changes may not be readily apparent with current clinical imaging instrumentation.

Personalized Medicine Bayesian Inference as Applied to the Measurement of Glaucomatous Visual Field Loss Personalized Medicine

Zarbin MA. — Thu, 13 Jun 2013 00:00:00 GMT

If presented with visual fields from a patient with central islands of vision, most of us would have difficulty in determining, on the basis of this information alone, the correct diagnosis. If we were given additional information that the intraocular pressure was 35 mm Hg OU, we might be more inclined to suggest that the visual field results signify the presence of advanced glaucoma. However, if we were then presented with fundus photographs illustrating diffuse waxy pallor of the optic nerves with no cupping, attenuated retinal vascular caliber at the optic nerve heads, and bone-spicule hyperplasia of the retinal pigment epithelium in a bilaterally symmetric pattern, we would probably conclude that the cause of the visual field findings is retinitis pigmentosa (RP). If we then obtained a family history and learned that the patient's father and paternal grandfather had been diagnosed as having RP, we would likely conclude that this is a case of autosomal dominant RP. If we obtained genetic testing and learned that there is a mutation in this patient's rhodopsin gene (eg, P23H), we would be confident in the diagnosis of RP. This patient illustrates how our assessment of the probability of a diagnosis is influenced by both the prior probability and the addition of new information. The probability of a diagnosis being correct increases as additional information that is consistent with that diagnosis is acquired, and it decreases as information that is not consistent with that diagnosis is acquired. Beyond a certain point, additional information only changes our level of certainty minimally. We also use this sort of reasoning to reject the validity of clinical data. If, for example, as part of a preoperative assessment, a patient's testing reveals an abnormally high prothrombin time (PT)/partial thromboplastin time (PTT) but the patient has no history of abnormal bleeding, does not use an anticoagulant, and does not have a history of rheumatological disease, we are likely to conclude that the result is spurious and are likely to either ignore the test or repeat it rather than initiate treatment with fresh frozen plasma before major surgery on the basis of the PT/PTT result alone. This approach is sound because the likelihood of the abnormal PT/PTT being a valid result, in view of all the other information available to us, is low.

Distinct Ocular Expression in Infants and Children With Down Syndrome in Cairo, Egypt Myopia and Heart Disease Ocular Manifestations of Down Syndrome in Cairo

Afifi HH, Abdel Azeem AA, El-Bassyouni HT, et al. — Thu, 13 Jun 2013 00:00:00 GMT

Importance

The study establishes the importance of genetic background for the expression of Down syndrome phenotype.

Objective

To define the ocular manifestations of Down syndrome in infants and children in Cairo, Egypt, a historically isolated region, and compare them with systemic features and with findings in other geographic groups.

Design and Participants

We prospectively studied the ocular status and systemic features of 90 infants and children with Down syndrome and monitored all patients for 3 years. The complete ophthalmic examinations were performed along with ultrasonography, if media opacities were evident. Thyroid and cardiac status were assessed. An extensive literature search for comparison was performed.

Setting

Outpatient clinical genetics department at the National Research Centre in Cairo, Egypt.

Main Outcomes and Measures

Ocular and systemic manifestations of Down syndrome in infants and children in Cairo, and comparison of these features with patients with this anomaly from other geographic regions and ethnic populations.

Results

Fifty-two infants or children (58%) had at least 1 abnormal ocular finding identified at the first visit. Significant refractive errors (in 37 [41%] patients) were the most common. Nasolacrimal duct obstruction, blepharoconjuctivitis, or conjunctivitis was found in 18 (20%), strabismus in 13 (14%), cataract in 5 (6%), nystagmus in 3 (3%), and optic nerve dysplasia in 2 (2%). Brushfield spots were not found. Additional ocular features developed over time. Thirty-six patients (40%) had congenital heart defects, and many (31 [86%]) had associated ocular disorders; a statistically significant correlation with myopia was established. Chromosomal translocations were high. The phenotype in Cairo was distinct.

Conclusions and Relevance

More than half of infants and children with Down syndrome in Cairo had ophthalmic abnormalities; myopia was correlated with congenital heart defects. Comparison of the specific ocular features in our population with those in previous worldwide studies shows differences that may be related to overexpression or polymorphisms of key, modifying genes or other mutations in this historically isolated region along the Nile River. Down syndrome is more common in the highly consanguineous and multiparous Middle Eastern populations, and our Cairo findings underscore regional differences.