Thomas N. Hwang

Giant cell arteritis in Asians: a comparative study

Background Giant cell arteritis (GCA) is a common systemic vasculitis, with a presumed Caucasian predominance. The occurrence of GCA in Asians has rarely been addressed. This study aims to assess the incidence of giant cell arteritis in Asians. Methods In this retrospective review, the self-reported ethnicities of patients with biopsy-proven GCA at the University of California–San Francisco (UCSF) were recorded. Ethnic distribution of the patient population served by UCSF was estimated from an age- and sex-matched control group. The odds ratio for each ethnicity (Asian and Caucasian) was determined and compared using Fishers exact test and logistic regression analysis. Results The ethnic distribution of the 38 patients with positive temporal artery biopsies were as follows: Caucasian n=31 (81.6%), Asian n=1 (2.6%) and other n=6 (15.8%). The ethnic distribution of the patient population served by UCSF was as follows: Caucasian 42%, Asian 28% and other 30%. The difference in the proportion of GCA in Asians and Caucasians was statistically significant (OR 0.049 (95% CI 0.0065 to 0.374), p=0.0036). Conclusions In our patient population, GCA was seen 20 times less frequently in Asian than Caucasian patients. Although this difference is significantly different (p=0.036), given the small sample size and wide CI this should be viewed as a rough estimate.

Automatic detection, characterization, and discrimination of kinetically distinct spontaneous synaptic events.

Rapid and reliable detection of randomly occurring small amplitude synaptic events resulting from activation of different classes of ligand-gated receptors is a difficult task. Here, we describe and characterize an amplitude threshold algorithm, written as an IGOR Pro procedure, which detects events as well as characterizes their amplitudes and kinetics. The program was developed to analyze recording traces that each contained both excitatory (glutamate-mediated) and inhibitory (GABA and glycine-mediated) events. By using differences in kinetics, the program could discriminate between the two different classes of events. In summary, the program has the following strengths: (1) it is generally applicable to circumstances in which different populations of elementary events occur concurrently, a drawback of methods that employ matched filtering techniques, (2) it is relatively insensitive to drifts in baseline, and (3) it generates user-accessible arrays of the timing, amplitude and kinetic parameters of the detected events, making customized statistical analysis of event characteristics easily executable.

Evisceration in the modern age.

Evisceration is an ophthalmic surgery that removes the internal contents of the eye followed usually by placement of an orbital implant to replace the lost ocular volume. Unlike enucleation, which involves removal of the entire eye, evisceration potentially causes exposure of uveal antigens; therefore, historically there has been a concern about sympathetic ophthalmic (SO) associated with evisceration. However, critical review of the literature shows that SO occurs very rarely, if ever, as a consequence of evisceration. Its clinical applications overlap with those of enucleation in cases of penetrating ocular trauma and blind painful eyes, but it is absolutely contraindicated in the setting of suspected intraocular malignancy and may be preferred for treatment of end-stage endophthalmitis. From a technical standpoint, traditional evisceration has a limitation in the orbital implant size. Innovations with scleral modification have overcome this limitation, and accordingly, due to its simplicity, efficiency, and good cosmetic results, evisceration has once again been gaining popularity.

Levator Superioris Muscle Function in Involutional Blepharoptosis

PURPOSE To assess the role of muscular degeneration, we evaluated the correlation between ptosis severity and levator muscle function. DESIGN Retrospective cohort study. METHODS The medical records of 136 patients (53 men and 83 women; mean age, 67 years) with acquired blepharoptosis were reviewed for levator function (LF), margin reflex distance (MRD), age, and gender. Multivariate linear regression was performed for statistical analysis. RESULTS A significant correlation (P < .001) was seen between MRD (mean, 1.0 + 1.0 mm; range, -3.0 to 3.0 mm) and LF (mean, 15.0 + 1.0 mm; range, 11.0 to 20.0 mm). On average, a 0.5-mm reduction in LF was observed for each 1.0-mm decrease in MRD. This was independent to other variables assessed. CONCLUSIONS In patients with involutional blepharoptosis, a directly proportional decrease in levator function and eyelid height was observed. This may implicate an abnormality of the levator muscle itself as a contributing factor in the development of involutional blepharoptosis.

Sunken Eyes, Sagging Brain Syndrome: Bilateral Enophthalmos from Chronic Intracranial Hypotension

PURPOSE To explain the mechanism for acquired enophthalmos after ventriculoperitoneal shunting (VPS). DESIGN Case series and a case-control study. PARTICIPANTS AND CONTROLS Four study patients with bilateral enophthalmos after VPS and 10 control subjects. METHODS Case description of 4 study patients. Calculated orbital volumes for 2 study patients were compared with controls using the Wilcoxon rank-sum test. MAIN OUTCOME MEASURES Exophthalmometry measurements and total orbital and fat volumes. RESULTS Patient 1 is a 25-year-old man who presented with progressive enophthalmos 3 years after VPS for traumatic intracranial bleeding. Imaging demonstrated upward expansion of the orbital roof and evidence of intracranial hypotension. The intracranial pressure (ICP) was 20 mm H₂O. The enophthalmos improved after shunt revision. Patient 2 is a 19-year-old man who presented with progressive enophthalmos 18 months after VPS for traumatic intracranial hemorrhage. Patient 3 is a 38-year-old woman who presented with bilateral enophthalmos 15 years after VPS after a ruptured aneurysm. Imaging showed orbital expansion. Patient 4 is a 16-year-old man who presented with severe enophthalmos 5 years after a VPS for aneurysm-related hemorrhage. Imaging demonstrated orbital enlargement and findings of intracranial hypotension. Intracranial pressure ranged between -200 and 0 mm H₂O. Shunt revision improved the enophthalmos. Total orbital volumes were significantly greater in the study patients than in the controls. Control subjects (5 male, 5 female, ages 23-45 years) had an average right orbital volume of 24.6 ± 3.3 cm³ (n = 10). In comparison, the right orbital volumes of patients 1 and 3 were 32.6 and 32.1 cm³. Similar results were found for the left orbits (23.9 ± 2.7 cm³ [control average] vs. 35.9 and 32.6 cm³). In patient 1, the post-shunt volumes increased 14% (right) and 23% (left) from pre-shunt volumes. In contrast, orbital fat volume was not statistically significantly different between the control group and enophthalmic patients (right orbit control mean 7.94 ± 3.1 cm³ [n = 10] vs. 7.9 and 9.8 cm³; left orbit control mean 7.88+3.1 cm³ vs. 9.2 and 10.0 cm³). CONCLUSIONS Enophthalmos after VPS results primarily from chronic intracranial hypotension. Low ICP causes expansion of orbital volume with no fat atrophy. In such patients, shunt revision with a pressure-regulating valve to correct intracranial hypotension should be considered. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Interactive image-guided endoscopic dacryocystorhinostomy

The authors describe dacryocystorhinostomy performed with CT guidance. A 53-year-old man with a history of cocaine abuse was referred for bilateral nasolacrimal duct obstruction. Nasal speculum examination revealed an oronasal fistula and obliteration of the inferior nasal septum. Bilaterally, the inferior and middle turbinates were contracted, forming thick scar tissue conglomerates. The loss of normal anatomic landmarks and extensive contracted scar tissue precluded standard dacryocystorhinostomy approaches. Endoscopic dacryocystorhinostomy was therefore undertaken using CT-guided navigation. The location of the superior nasolacrimal duct was identified and subsequently exposed. Dissection was continued superiorly, marsupializing the lacrimal sac. Silicon stents were placed and tied intranasally. Right and left sides were managed similarly. Several months later, following stent removal, the patient was without epiphora. This case demonstrates that CT guidance can be a useful adjunct to standard dacryocystorhinostomy techniques, allowing otherwise challenging surgical cases to be managed effectively and safely.

Acquired enophthalmos in lupus erythematosus profundus

Lupus erythematosus profundus (LEP) is an uncommon subtype of lupus erythematosus. A 76-year old man presented with inflammation of the eyelids and underlying orbital soft tissue. A biopsy disclosed inflammation and atrophy of the orbital fat consistent with LEP. Systemic corticosteroid treatment produced resolution of the inflammation. but as the edema subsided, enophthalmos became apparent. LEP should be considered in patients with a characteristic rash and orbital inflammation and may cause acquired enophthalmos.

Adult orbital trapdoor fracture.

Trapdoor fractures occur almost exclusively in the pediatric population. The authors describe an adult with an entrapped inferior rectus muscle sheath in a trapdoor fracture. A 37-year-old man presented with persistent diplopia 3 weeks after blunt right orbital trauma. The only abnormal findings on clinical examination were limited vertical ductions. No bony defect or displacement was evident on CT. However, several small pockets of air were visible adjacent to the inferior rectus muscle. On surgical exploration, a linear nondisplaced orbital floor fracture was confirmed, and the entrapped inferior rectus muscle was released. One month postoperatively, extraocular motility had improved with no diplopia in primary or reading positions. This case demonstrates that trapdoor fractures can occur in adults and should be considered when suggestive findings are encountered. Clinicians should be aware of this because timely diagnosis and treatment might achieve more favorable outcomes.

Comparison of Humphrey Matrix frequency doubling technology to standard automated perimetry in neuro-ophthalmic disease.

Purpose: We compared Humphrey Matrix FDT 30-2 (FDT) and Humphrey Visual Field Analyzer 30-2 SITA standard (SAP) in the assessment of anterior (optic nerve or chiasm) and posterior (retro-chiasmal) afferent visual pathway defects. Materials and Methods: In this retrospective comparative study, the charts of 37 patients (16 males, range 13-84 years, mean 72.1), with neuro-ophthalmic visual field defects who were tested with both FDT and SAP, were reviewed. Two masked graders assessed the concordance and extent of field defects between the perimeters. The mean concordance between anterior and posterior disease was compared using the Wilcoxon rank sum test. The mean deviation (MD) and pattern standard deviation (PSD) of each perimeter were correlated with the Spearman coefficient. Results: Twenty-eight patients had anterior and nine had posterior disease. Most had a fair or good concordance (89.3% anterior, 88.9% posterior). When comparing anterior to posterior disease, the mean concordance of the defects of the two parameters was not statistically different (P = 0.94 and P = 0.61 for total deviation and pattern deviation, respectively). The MD and PSD between perimeters had a significant correlation. Conclusions: Our series, using 30-2 field analysis, demonstrates fair to good correlation between FDT and SAP in the majority of patients. In roughly 10% findings between FDT and SAP were discordant. This difference was similar for anterior and posterior disease.

Amyloidosis-associated neurotrophic keratopathy precipitated by overcorrected blepharoptosis.

Purpose: To describe amyloidosis-associated neurotrophic keratopathy. Methods: In this interventional case report, we describe the clinical findings of a patient with amyloidosis-associated neurotrophic keratopathy, precipitated by exposure from overcorrected blepharoptosis. Results: A 70-year-old woman with a history of amyloidosis was referred with bilateral eyelid retraction 1 month after levator aponeurosis advancement surgery. Examination demonstrated visual acuities of count-fingers OD and 20/400 OS and severe corneal epithelial irregularity with diffuse fluorescein staining. She had marked eyelid retraction with 5-mm right and 3-mm left superior scleral show and incomplete closure. Corneas were anesthetic, and neurologic examination was notable for peripheral sensory loss. Despite eyelid position normalization, the corneal abnormalities progressed to large epithelial defects refractory to aggressive lubrication, punctal occlusion, bandage contact lenses, extended patching, and ultimately tarsorrhaphy consistent with neurotrophic keratopathy. One year postoperatively, the epithelial disease persists. Conclusion: Neurotrophic keratopathy can occur in association with amyloidosis and may be precipitated by exposure related to blepharoptosis repair.