Publications

2012

Chui T, Bissig D, Berkowitz B, Akula J. Refractive Development in the "ROP Rat". J Ophthalmol. 2012;2012:956705.
Although retinopathy of prematurity (ROP) is clinically characterized by abnormal retinal vessels at the posterior pole of the eye, it is also commonly characterized by vascular abnormalities in the anterior segment, visual dysfunction which is based in retinal dysfunction, and, most commonly of all, arrested eye growth and high refractive error, particularly (and paradoxically) myopia. The oxygen-induced retinopathy rat model of ROP presents neurovascular outcomes similar to the human disease, although it is not yet known if the "ROP rat" also models the small-eyed myopia characteristic of ROP. In this study, magnetic resonance images (MRIs) of albino (Sprague-Dawley) and pigmented (Long-Evans) ROP rat eyes, and age- and strain-matched room-air-reared (RAR) controls, were examined. The positions and curvatures of the various optical media were measured and the refractive state (℞) of each eye estimated based on a previously published model. Even in adulthood (postnatal day 50), Sprague-Dawley and Long-Evans ROP rats were significantly myopic compared to strain-matched controls. The myopia in the Long-Evans ROP rats was more severe than in the Sprague-Dawley ROP rats, which also had significantly shorter axial lengths. These data reveal the ROP rat to be a novel and potentially informative approach to investigating physiological mechanisms in myopia in general and the myopia peculiar to ROP in particular.
Dagi L, Bhargava A, Melvin P, Prabhu S. Associated signs, demographic characteristics, and management of dacryocystocele in 64 infants. J AAPOS. 2012;16(3):255–60.
PURPOSE: To describe the incidence of associated infection, respiratory compromise, apparent intranasal cyst, as well as sex, laterality, and age at presentation in 64 infants with dacryocystocele and to assess characteristics associated with successful interventions. METHODS: A retrospective chart review of all patients with dacryocystocele seen at Children's Hospital Boston between 1996 and 2010 was performed. Inclusion criteria were accuracy of diagnosis, treatment, and follow-up at our institution. Interventions were divided into 3 categories: procedures that did not require general anesthesia; simple procedures requiring general anesthesia, such as nasolacrimal probing with or without stent or balloon dilation; and more complex procedures under general anesthesia, specifically, those aided by intranasal endoscopy. RESULTS: Of the 90 identified patients, 64 met inclusion criteria. The majority of patients were female (63%) and had unilateral involvement (77%). More than one-half of all patients were successfully treated without anesthesia; however, patients presenting with infection were more likely to be treated with a simple procedure under general anesthesia. All patients treated endoscopically had intranasal cysts. Age, sex, and infection did not predict the use of intranasal endoscopy. Bilaterality of dacryocystocele was associated with the use of an endoscopic approach. CONCLUSIONS: Many infants with dacryocystocoele can be successfully treated without general anesthesia. The incidence of occult intranasal cyst among those treated without endoscopy remains unknown. Patients who were treated under general anesthesia but without the use of nasal endoscopy were more likely to have an infected system, but the clinical significance of this association is not clear.
Daniels A, Lee JE, MacConaill L, Palescandolo E, Hummelen P, Adams S, Deangelis M, Hahn W, Gragoudas E, Harbour W, Garraway L, Kim I. High throughput mass spectrometry-based mutation profiling of primary uveal melanoma. Invest Ophthalmol Vis Sci. 2012;53(11):6991–6.
PURPOSE: We assessed for mutations in a large number of oncogenes and tumor suppressor genes in primary uveal melanomas using a high-throughput profiling system. METHODS: DNA was extracted and purified from 134 tissue samples from fresh-frozen tissues (n = 87) or formalin-fixed, paraffin-embedded tissues (n = 47) from 124 large uveal melanomas that underwent primary treatment by enucleation. DNA was subjected to whole genome amplification and MALDI-TOF mass spectrometry-based mutation profiling (>1000 mutations tested across 120 oncogenes and tumor suppressor genes) using the OncoMap3 platform. All candidate mutations, as well as commonly occurring mutations in GNAQ and GNA11, were validated using homogeneous mass extension (hME) technology. RESULTS: Of 123 samples, 97 (79%, representing 89 unique tumors) were amplified successfully, passed all quality control steps, and were assayed with the OncoMap platform. A total of 58 mutation calls was made for 49 different mutations across 26 different genes in 34/98 (35%) samples. Of 91 tumors that underwent hME validation, 83 (91%) harbored mutations in the GNAQ (47%) or GNA11 (44%) genes, while hME validation revealed two tumors with mutations in EGFR. These additional mutations occurred in tumors that also had mutations in GNAQ or GNA11. CONCLUSIONS: The vast majority of primary large uveal melanomas harbor mutually-exclusive mutations in GNAQ or GNA11, but very rarely have the oncogenic mutations that are reported commonly in other cancers. When present, these other mutations were found in conjunction with GNAQ/GNA11 mutations, suggesting that these other mutations likely are not the primary drivers of oncogenesis in uveal melanoma.
Daniels A, Sandberg M, Chen J, Weigel-DiFranco C, Fielding Hejtmancic, Berson E. Genotype-phenotype correlations in Bardet-Biedl syndrome. Arch Ophthalmol. 2012;130(7):901–7.
OBJECTIVE: To determine whether mutations in different Bardet-Biedl syndrome (BBS) genes result in different ocular phenotypes. METHODS: Thirty-seven patients from 31 families were enrolled who met the clinical criteria for BBS and for whom a BBS mutation had been identified. Seventeen patients harbored mutations in BBS1, 10 in BBS10, and 10 in other genes (BBS2, BBS3, BBS5, BBS7, and BBS12). All the patients underwent ocular examination; 36 patients had computerized full-field electroretinograms (ERGs). RESULTS: Visual acuity was significantly better in BBS1 patients than in patients with other BBS mutations (P=.01), and a larger proportion of BBS1 patients had good (≥20/50) visual acuity (P=.01). The ERG amplitudes were significantly higher in BBS1 patients than in patients with other BBS mutations in response to 0.5-Hz and 30-Hz flashes (P<.001 for both). All the BBS1 patients harbored at least 1 missense mutation compared with only 45% of patients with mutations in other BBS genes (P<.001); the rest harbored only null alleles. However, multivariate analysis demonstrated that visual acuity or ERG amplitude did not depend on the type of mutation present (missense or null) when controlling for BBS gene. Prevalences of bone spicule pigmentation and cataract were comparable in BBS subtypes. CONCLUSIONS: Patients with BBS1 mutations had a milder phenotype than did patients with mutations in other BBS genes. Clinically, this manifested as significantly better visual acuity and larger ERG amplitudes. CLINICAL RELEVANCE: These phenotypic differences can help guide genetic testing and genetic counseling for patients with this syndrome.
De Castro D, Hadlock T, Fay A. Dynamic imaging of paralytic eyelid disorders. Semin Ophthalmol. 2012;27(5-6):167–74.
PURPOSE: Eyelid dysmotility may result from trauma, tumors, inflammation, infection, and a variety of other conditions. In these cases, a mechanical effect is disrupting a normal neuromuscular apparatus. Dysmotility can also be caused by paralytic eyelid disorders; included in this broad category are neurologic and myogenic disorders of eyelid opening and/or closure. Secondary effects include spastic eyelid closure and synkinesis syndromes. These conditions, by definition, are disorders of movement, and can only be studied adequately using dynamic imaging techniques. METHODS: A comprehensive literature search was performed on PubMed. Ninety abstracts were reviewed. RESULTS: Dynamic eyelid imaging has evolved dramatically over the past two decades, at least partially due to the rise of inexpensive digital technology. Magnetic search coil imaging, high- and low-speed videography, electromyography, and high-resolution microscopy coil magnetic resonance imaging each has its advantages and disadvantages, an understanding of which will guide appropriate selection of technology in any given clinical situation. CONCLUSIONS: Dynamic eyelid imaging is useful to study dysmotility. The optimal technique depends upon the clinical setting and the physiologic or pathologic topic of interest. To our knowledge, a report of this type has not been previously summarized.
Dela Paz N, Walshe T, Leach L, Saint-Geniez M, D’Amore P. Role of shear-stress-induced VEGF expression in endothelial cell survival. J Cell Sci. 2012;125(Pt 4):831–43.
Vascular endothelial growth factor (VEGF) plays a crucial role in developmental and pathological angiogenesis. Expression of VEGF in quiescent adult tissue suggests a potential role in the maintenance of mature blood vessels. We demonstrate, using a Vegf-lacZ reporter mouse model, that VEGF is expressed by arterial but not by venous or capillary endothelial cells (ECs) in vivo. Using an in vitro model, we show that arterial shear stress of human umbilical vein ECs (HUVECs) decreases apoptosis and increases VEGF expression, which is mediated by the induction of Krüppel-like factor 2 (KLF2). Additionally, shear stress stimulates the expression of VEGF receptor 2 (VEGFR2) and is associated with its activation. Knockdown of VEGF in shear stressed HUVECs blocks the protective effect of shear stress, resulting in EC apoptosis equivalent to that in control ECs cultured under static conditions. Similarly, treatment of ECs subjected to arterial shear stress with the VEGF receptor tyrosine kinase inhibitor SU1498, or VEGFR2 neutralizing antiserum, led to increased apoptosis, demonstrating that the mechanoprotection from increased shear is mediated by VEGFR2. Taken together, these studies suggest that arterial flow induces VEGF-VEGFR2 autocrine-juxtacrine signaling, which is a previously unidentified mechanism for vascular EC survival in adult arterial blood vessels.
Ding J, Sullivan D. Aging and dry eye disease. Exp Gerontol. 2012;47(7):483–90.
Dry eye disease is a prevalent eye disorder that in particular affects the elderly population. One of the major causes of dry eye, meibomian gland dysfunction (MGD), shows increased prevalence with aging. MGD is caused by hyperkeratinization of the ductal epithelium of meibomian gland and reduced quantity and/or quality of meibum, the holocrine product that stabilizes and prevents the evaporation of the tear film. Of note, retinoids which are used in current anti-aging cosmetics may promote the development of MGD and dry eye disease. In this review, we will discuss the possible mechanisms of age-related MGD.
Durrani K, Foster S. Fundus autofluorescence imaging in posterior uveitis. Semin Ophthalmol. 2012;27(5-6):228–35.
Although the phenomenon of fundus autofluorescence has been known for decades, it has only recently been recognized as a measure of retinal pigment epithelial function and health. Characteristic fundus autofluorescence patterns have been described in eyes affected by inflammation of the posterior segment, and these patterns have provided insights into the pathogenesis of posterior uveitis entities. In addition, preliminary data indicate that fundus autofluorescence characteristics may serve as markers of disease activity, allow prediction of visual prognosis, and may help determine the adequacy of therapy. We provide an overview of the current state of fundus autofluorescence imaging technology and review our current knowledge of fundus autoflourescence findings and their clinical use in the posterior uveitis entities.