PURPOSE OF REVIEW: To summarize recent advances in the diagnosis of giant cell arteritis (GCA). RECENT FINDINGS: Less common manifestations of GCA include corneal edema, proptosis from lacrimal gland ischemia and sensorineuronal hearing loss. Histology studies have suggested that temporal artery biopsies (TAB) with fixed specimen lengths of 15 mm may be adequate to prevent false negative biopsies. In centers with appropriate radiologic expertise, a European rheumatology consensus guideline has proposed Doppler ultrasound as a first-line confirmatory test for GCA in lieu of temporal artery biopsy. Finding extracranial large vessel disease can help to diagnose GCA. Statistical prediction rules can help risk stratify patients with suspected GCA. Age and platelet level when maintained as continuous variables are the strongest predictors for GCA. SUMMARY: GCA can present with diverse ophthalmic and systemic presentations and expedient recognition of same can avoid diagnostic delay and possible vision loss, among other complications. TAB remains the conventional diagnostic standard test for GCA. The use of statistical prediction models and increased expertise in noninvasive imaging techniques such as ultrasound may decrease reliance on TAB, especially in patients determined to be at low risk for GCA.

The mucosal glycocalyx of the ocular surface constitutes the point of interaction between the tear film and the apical epithelial cells. Membrane-associated mucins (MAMs) are the defining molecules of the glycocalyx in all mucosal epithelia. Long recognized for their biophysical properties of hydration, lubrication, anti-adhesion and repulsion, MAMs maintain the wet ocular surface, lubricate the blink, stabilize the tear film and create a physical barrier to the outside world. However, it is increasingly appreciated that MAMs also function as cell surface receptors that transduce information from the outside to the inside of the cell. A number of excellent review articles have provided perspective on the field as it has progressed since 1987, when molecular cloning of the first MAM was reported. The current article provides an update for the ocular surface, placing it into the broad context of findings made in other organ systems, and including new genes, new protein functions and new biological roles. We discuss the epithelial tissue-equivalent with mucosal differentiation, the key model system making these advances possible. In addition, we make the first systematic comparison of MAMs in human and mouse, establishing the basis for using knockout mice for investigations with the complexity of an in vivo system. Lastly, we discuss findings from human genetics/genomics, which are providing clues to new MAM roles previously unimagined. Taken together, this information allows us to generate hypotheses for the next stage of investigation to expand our knowledge of MAM function in intracellular signaling and roles unique to the ocular surface.

Meibomian gland dysfunction (MGD) is the leading cause of evaporative dry eye disease and is one of the most common conditions encountered by eye care providers. MGD is characterized by obstruction of the meibomian gland terminal ducts and/or changes in their glandular secretion, resulting in changes in tear film stability, inflammation, and symptoms of irritation. There is no gold standard treatment for MGD, but rather a diversity of options. Conservative measures include warm compresses and lid hygiene, but there is growing interest and need for medical treatments and procedures. Potential medical treatments include antibiotics, non-steroidal and steroidal anti-inflammatory agents, essential fatty acid supplementation, hormone therapy, and control of Demodex infestation. Procedures include intraductal meibomian gland probing, the use of electronic heating devices, intense pulsed light therapy, and intranasal neurostimulation. We provide an update on MGD treatments based on recent studies.

The light-sensitive photoreceptors in the retina are extremely metabolically demanding and have the highest density of mitochondria of any cell in the body. Both physiological and pathological retinal vascular growth and regression are controlled by photoreceptor energy demands. It is critical to understand the energy demands of photoreceptors and fuel sources supplying them to understand neurovascular diseases. Retinas are very rich in lipids, which are continuously recycled as lipid-rich photoreceptor outer segments are shed and reformed and dietary intake of lipids modulates retinal lipid composition. Lipids (as well as glucose) are fuel substrates for photoreceptor mitochondria. Dyslipidemia contributes to the development and progression of retinal dysfunction in many eye diseases. Here, we review photoreceptor energy demands with a focus on lipid metabolism in retinal neurovascular disorders.

Purpose: To report a postmenopausal patient with keratoconus who experienced significant progression after using hormone replacement therapy. Observations: A 51-year-old woman with previously stable keratoconus presented with acute disease progression following hormone replacement therapy in the context of prophylactic hysterectomy and bilateral ovariosalpingectomy. Over a 14-month period after starting hormone therapy, the steepest K increased from 63.7D to 71.5D in the right eye and from 65.8D to 78.1D in the left eye. Conclusions: Hormone replacement therapy may amplify progression of keratoconus.

Purpose: The clinical features of autoimmune retinopathy (AIR) can resemble and be difficult to differentiate from inherited retinal degenerations (IRDs). Misdiagnosis of an IRD as AIR causes unnecessary treatment with immunosuppressive agents. The purpose of this study is to calculate the predictive value of genetic testing for IRDs in patients with suspected AIR and provide clinical examples where genetic testing has been useful. Methods: We identified patients seen at MEEI between April 2013 and January 2017 for whom the differentiation of AIR vs. IRDs was difficult based on clinical assessment alone. All patients had some atypical features for AIR, but tested positive for anti-retinal antibodies. Within this group, we identified six patients who had genetic testing for IRDs with the Genetic Eye Disease panel for retinal genes (GEDi-R). We calculated the positive predictive value (PPV) and negative predictive value (NPV) of genetic testing in a population with approximately equal numbers of IRD and AIR patients. Results: Six patients had clinical features that made distinguishing between IRDs and AIR on a clinical basis difficult and were sent for genetic testing: four women and two men with a mean age of 59.5 years. In two of these six patients, genetic diagnoses were made based upon the identification of known pathogenic variants in the common IRD genes and . Two patients had variants of unknown significance within genes associated with IRDs, and the other two had no relevant genetic findings. Given the 60% sensitivity and 3% false positive rate for GEDi-R testing and assuming a 50% pre-test probability of having an IRD, the PPV for GEDi-R for detecting IRD is 95.2% and the NPV is 70.8%. Conclusions and Importance: In patients for whom the differential diagnosis of AIR and IRDs is unclear based on clinical information, genetic testing can be a valuable tool when it identifies an IRD, sparing the patient unnecessary immunosuppressive treatment. However, the test has a low NPV so a negative genetic testing result does not confidently exclude IRD as the true diagnosis.

PURPOSE OF REVIEW: Optic neuritis is an autoimmune optic neuropathy that has been associated with multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and more recently antimyelin oligodendrocyte glycoprotein (anti-MOG)-positive disorder. At initial presentation, it is often difficult to differentiate these entities given their significant overlap in clinical presentation and MRI findings. This review summarizes the distinguishing clinical and radiological features of MS, NMOSD, and anti-MOG disorders to help clinicians accurately diagnose and manage patients affected by these conditions. RECENT FINDINGS: Antiaquaporin-4 (AQP4) and more recently anti-MOG antibodies are both associated with central nervous system demyelinating diseases that often initially present with optic neuritis. Serologic testing now allows for a new classification of these overlapping conditions that can help to differentiate 'typical' optic neuritis that is often associated with MS from 'atypical' optic neuritis associated with NMOSD and anti-MOG-positive disorder. SUMMARY: Optic neuritis associated with MS, NMOSD, and anti-MOG-positive disease can have a similar clinical presentation. However, some clinical and radiologic findings can help clinicians to differentiate these entities so that they can be properly managed to optimize visual prognosis.