Persistent orbital inflammation following complete excision of deep dermoid cysts.

Piecemeal excision of dermoid cysts carries the risk of implanting epithelial fragments into orbital fat, which is well recognized to continue secreting oily debris, inciting chronic, often granulomatous inflammation. The authors present the clinical and histological details for two patients with persistent lipogranulomatous inflammation for years after piecemeal excision of deep orbital dermoid cysts, in the absence of any residual epithelium. The importance of copious saline lavage - to 'float-out" and reduce microscopic lipid droplets - is also emphasised.

Developmental Cysts of the Orbit With Mixed Conjunctival and Cutaneous Epithelial Phenotypes.

AIM: To describe the characteristics of patients presenting with congenital orbital cysts containing epithelia of both cutaneous phenotype-that is, epidermis with or without keratin, and at least one dermal structure (sweat gland or pilosebaceous unit)-and conjunctival phenotype (with goblet cells); these cysts with mixed lining are termed "dermo-conjunctival" cysts. PATIENTS AND METHODS: Review of clinical records for patients having dermo-conjunctival cysts that were treated between 1997 and 2017; patients with cysts of solely conjunctival or solely cutaneous origin were omitted. Data recorded included gender, age at presentation, laterality, orbital location, ophthalmic features, surgical and radiological data, and light microscopic findings. RESULTS: Of 241 patients with congenital orbital cysts, 22 (9%) contained both cutaneous and conjunctival epithelium; unlike the relatively common congenital cysts lined with solely cutaneous epithelia, these dermo-conjunctival cysts typically occupied the superonasal or nasal quadrants of the orbit (p < 0.000001). Fifteen (68%) of the 22 patients were male, and the group presented at a median age of 22 years (range 8-51 years), with symptoms for a median duration of 5 years (range 1 month-33 years). Fourteen (64%) had noted an orbital mass, 3 (14%) had inflammatory pain, and 1/22 (4%) had reduced acuity. Globe displacement was axial in 7 patients (32%) and nonaxial in 13 (59%), and ocular motility was restricted in 4/22 (18%). Of 17 patients with imaging, 9 (53%) had bone expansion, and the cyst was intimately related to the trochlea in 10 (59%). By definition, all cysts contained conjunctival epithelium with goblet cells: hair shafts were present in 13/22 (59%) specimens, sebaceous units in 18 (82%), sweat glands in 6 (27%), and keratinized epithelium was present in 8 (36%). Fourteen (63%) of cysts had mild chronic inflammation within the cyst wall, and granulomas were present in 8 (36%). CONCLUSION: Congenital dermo-conjunctival orbital cysts are rare and favor a medial location-this suggesting an origin from sequestered caruncular tissues, the only postseptal source of both dermal and conjunctival structures. Unlike pure cutaneous cysts that typically present as superficial masses in childhood, dermo-conjunctival cysts are often postseptal and present in adults.

Congenital Conjunctival Cysts of the Orbit.

PURPOSE: To evaluate the clinical presentation, anatomical location, and histological features of congenital conjunctival cysts of the orbit. The location and the histological features of inflammation in these patients were compared with those for 293 orbital dermoid cysts. PATIENTS AND METHODS: Retrospective review of the clinical details, imaging, and histopathology for patients who had excision of conjunctival cysts from their orbit between 1992 and 2020; patients with a history of trauma or surgery were omitted. RESULTS: Twelve patients (7 male; 58%) with congenital conjunctival cysts were identified, the patients presenting at an average age of 16 years (median 26; range 1-61) with a symptoms for a mean duration of 20 months (median 24; range 6-36). The commonest symptoms were peribulbar lump (6/12 patients; 50%), and eyelid swelling and blepharoptosis (6/12 patients; 50%). An orbitaxl mass was palpable in 10 patients (83%), 3 patients (25%) had mild proptosis (1-3 mm), and the cysts were most commonly located superiorly (6/12 patients; 50%) or superonasally (3/12; 25%) in the anterior half of the orbit. Imaging was performed in 7 cases, this showing an intimate relation to the common sheath of the superior rectus/levator complex in 3 patients (25%) and to the trochlea in 1 (8%). All cysts were excised completely, and no patient had postoperative complications or recurrence. Chronic mild and nonspecific inflammation was evident within the cyst wall in 7 cases (54%), but-unlike 55% of the 293 dermoid cysts-none showed granuloma formation. CONCLUSION: Congenital conjunctival cysts are rare and usually present with a palpable mass in the upper eyelid sulcus. A significant proportion of these cysts have an intimate relationship with the trochlea, or the superior rectus, levator palpebrae or superior oblique muscles and, to minimize the risk of postoperative diplopia or ptosis, particular care must be exercised during surgery.

Orbital involvement of Sitosterolemia.

Sitosterolemia is a rare inherited condition in which plant sterols are stored and deposited in the tissues. Described in 1974 by Battacharyya and Connor, it is characterized by tendon and tuberous xanthomas and a propensity to premature coronary atherosclerosis. We present the first reported case of the disease being manifest in the periorbital region. A 44-year-old man presented with a six-month history of swelling below the left eyebrow overlying the orbital rim, but without displacement of the globe. Magnetic resonance imaging identified a soft tissue mass within the orbit, with subsequent biopsy confirming a xanthogranulomatous process consistent with the diagnosis of sitosterolemia. Management of sitosterolemia aims to reduce plasma plant sterol concentrations which subsequently lowers serum cholesterol reducing the xanthomas and atherosclerotic cardiovascular diseases. This report highlights a rare, under-recognised condition (and indeed the first reporting periocular disease), and the potential dangers if misdiagnosed as hypercholesterolemia.

Ectopic GRHL2 Expression Due to Non-coding Mutations Promotes Cell State Transition and Causes Posterior Polymorphous Corneal Dystrophy 4.

In a large family of Czech origin, we mapped a locus for an autosomal-dominant corneal endothelial dystrophy, posterior polymorphous corneal dystrophy 4 (PPCD4), to 8q22.3-q24.12. Whole-genome sequencing identified a unique variant (c.20+544G>T) in this locus, within an intronic regulatory region of GRHL2. Targeted sequencing identified the same variant in three additional previously unsolved PPCD-affected families, including a de novo occurrence that suggests this is a recurrent mutation. Two further unique variants were identified in intron 1 of GRHL2 (c.20+257delT and c.20+133delA) in unrelated PPCD-affected families. GRHL2 is a transcription factor that suppresses epithelial-to-mesenchymal transition (EMT) and is a direct transcriptional repressor of ZEB1. ZEB1 mutations leading to haploinsufficiency cause PPCD3. We previously identified promoter mutations in OVOL2, a gene not normally expressed in the corneal endothelium, as the cause of PPCD1. OVOL2 drives mesenchymal-to-epithelial transition (MET) by directly inhibiting EMT-inducing transcription factors, such as ZEB1. Here, we demonstrate that the GRHL2 regulatory variants identified in PPCD4-affected individuals induce increased transcriptional activity in vitro. Furthermore, although GRHL2 is not expressed in corneal endothelial cells in control tissue, we detected GRHL2 in the corneal "endothelium" in PPCD4 tissue. These cells were also positive for epithelial markers E-Cadherin and Cytokeratin 7, indicating they have transitioned to an epithelial-like cell type. We suggest that mutations inducing MET within the corneal endothelium are a convergent pathogenic mechanism leading to dysfunction of the endothelial barrier and disease.

Peripapillary Hyper-reflective Ovoid Mass-like Structure (PHOMS): An Optical Coherence Tomography Marker of Axoplasmic Stasis in the Optic Nerve Head.

BACKGROUND: With the development and widespread adoption of spectral-domain optical coherence tomography (OCT), peripapillary hyper-reflective ovoid mass-like structures (PHOMS) have become a frequent OCT finding in neuro-ophthalmic practice. Although originally assumed to represent a form of buried optic disc drusen (ODD), PHOMS differ from ODD in many important ways. The histopathological underpinnings of PHOMS are now becoming more clearly understood. EVIDENCE ACQUISITION: Review of literature. RESULTS: PHOMS can be broadly classified as disk edema-associated PHOMS, ODD-associated PHOMS, or anomalous disk-associated PHOMS. PHOMS are seen in many conditions, including papilledema, nonarteritic anterior ischemic optic neuropathy, central retinal vein occlusion, acute demyelinating optic neuritis, ODD, and tilted disks (myopic obliquely inserted disks) and in many cases resolve along with the underlying condition. The histopathological study of these diverse entities reveals the common feature of a bulge of optic nerve fibers herniating centrifugally over Bruch membrane opening into the peripapillary space, correlating exactly with the location, shape, and space-occupying nature of PHOMS on OCT. Because of the radial symmetry of these herniating optic nerve fibers, PHOMS are best thought of as a complete or partial torus (i.e., donut) in 3 dimensions. CONCLUSIONS: PHOMS are a common but nonspecific OCT marker of axoplasmic stasis in the optic nerve head. They are not themselves ODD or ODD precursors, although they can be seen in association with ODD and a wide spectrum of other conditions. They do not exclude papilledema and often accompany it. The circumferential extent and characteristic 3D toroidal nature of a PHOMS are best appreciated by scrolling through consecutive OCT images.

Autosomal-Dominant Corneal Endothelial Dystrophies CHED1 and PPCD1 Are Allelic Disorders Caused by Non-coding Mutations in the Promoter of OVOL2.

Congenital hereditary endothelial dystrophy 1 (CHED1) and posterior polymorphous corneal dystrophy 1 (PPCD1) are autosomal-dominant corneal endothelial dystrophies that have been genetically mapped to overlapping loci on the short arm of chromosome 20. We combined genetic and genomic approaches to identify the cause of disease in extensive pedigrees comprising over 100 affected individuals. After exclusion of pathogenic coding, splice-site, and copy-number variations, a parallel approach using targeted and whole-genome sequencing facilitated the identification of pathogenic variants in a conserved region of the OVOL2 proximal promoter sequence in the index families (c.-339_361dup for CHED1 and c.-370T>C for PPCD1). Direct sequencing of the OVOL2 promoter in other unrelated affected individuals identified two additional mutations within the conserved proximal promoter sequence (c.-274T>G and c.-307T>C). OVOL2 encodes ovo-like zinc finger 2, a C2H2 zinc-finger transcription factor that regulates mesenchymal-to-epithelial transition and acts as a direct transcriptional repressor of the established PPCD-associated gene ZEB1. Interestingly, we did not detect OVOL2 expression in the normal corneal endothelium. Our in vitro data demonstrate that all four mutated OVOL2 promoters exhibited more transcriptional activity than the corresponding wild-type promoter, and we postulate that the mutations identified create cryptic cis-acting regulatory sequence binding sites that drive aberrant OVOL2 expression during endothelial cell development. Our data establish CHED1 and PPCD1 as allelic conditions and show that CHED1 represents the extreme of what can be considered a disease spectrum. They also implicate transcriptional dysregulation of OVOL2 as a common cause of dominantly inherited corneal endothelial dystrophies.

Immunohistochemical characterization of feline lymphoplasmacytic anterior uveitis.

OBJECTIVE: To characterize the immune cells present in different forms of feline anterior uveitis. SAMPLES: Eyes were obtained from 49 cats diagnosed with chronic idiopathic lymphoplasmacytic anterior uveitis, 7 cats with feline infectious peritonitis (FIP), and 9 cats euthanized for nonocular disease. METHODS: H&E sections were scored on the level of infiltrate in the anterior uvea. Immunohistochemistry was performed for FoxP3, CD3, and IL-17A, and positive cells were quantified in multiple images of each sample. A generalized estimating equation tested for an association between the level of inflammation and the prevalence of these cell types. RESULTS: Cells stained positive for IL-17A in idiopathic uveitis but not in FIP samples. We found significantly fewer FoxP3+ and CD3+ cells in low-grade compared with high-grade inflammation in idiopathic uveitis or FIP samples (P values all <.005), but no difference between FIP and high-grade samples. CONCLUSIONS: Idiopathic, but not FIP-associated, uveitis appears to have Th17 cell involvement. The numbers of FoxP3+ and CD3+ T-cells present appear directly correlated; thus, the severity of disease does not appear directly determined by the numbers of regulatory cells.

Detection of extrascleral extension in uveal melanoma with histopathological correlation.

PURPOSE: Uveal melanoma is the most common primary intraocular malignancy. Extrascleral extension (ESE) is rare, but associated with an increased rate of orbital recurrence and an overall poor prognosis. Clinical studies show low rates when compared with histological studies. Due to the prognostic importance of ESE, we sought to compare our clinical, intraoperative, and histological detection rates. DESIGN: A retrospective cross-sectional case series. METHODS: A list of eyes enucleated for uveal melanoma was compiled from the admissions records of the London Ocular Oncology Service during the 28-month period, i.e. January 2010-April 2012. The surgical and clinical notes of patients with histopathology proven ESE were reviewed to determine when it was first diagnosed or suspected. The subsequent management of these cases is discussed. RESULTS: A total of 16 out of 174 (9%) eyes had histologically proven ESE. Eight of 16 cases were detected preoperatively at clinical examination, including the use of ocular ultrasound, 3 of 16 were discovered intra-operatively, and 5 of 16 deemed microscopic ESE, were first detected on histological examination. Seven of 7 (100%) of cases with anterior ESE were detected clinically by slit lamp biomicroscopy, while only 1 out of 9 (11%) of cases with posterior ESE was detected preoperatively with ultrasound. CONCLUSIONS: Slit lamp biomicroscopy is sensitive for detecting anterior ESE. Most posterior ESE is microscopic, but macroscopic posterior ESE may also be missed by B-scan ocular ultrasound. Orbital surgeons should be suspicious of clinically undetected posterior ESE, and consider adjuvant orbital radiotherapy in cases with macroscopic ESE.

A dominant-negative mutation of mouse Lmx1b causes glaucoma and is semi-lethal via LDB1-mediated dimerization [corrected].

Mutations in the LIM-homeodomain transcription factor LMX1B cause nail-patella syndrome, an autosomal dominant pleiotrophic human disorder in which nail, patella and elbow dysplasia is associated with other skeletal abnormalities and variably nephropathy and glaucoma. It is thought to be a haploinsufficient disorder. Studies in the mouse have shown that during development Lmx1b controls limb dorsal-ventral patterning and is also required for kidney and eye development, midbrain-hindbrain boundary establishment and the specification of specific neuronal subtypes. Mice completely deficient for Lmx1b die at birth. In contrast to the situation in humans, heterozygous null mice do not have a mutant phenotype. Here we report a novel mouse mutant Icst, an N-ethyl-N-nitrosourea-induced missense substitution, V265D, in the homeodomain of LMX1B that abolishes DNA binding and thereby the ability to transactivate other genes. Although the homozygous phenotypic consequences of Icst and the null allele of Lmx1b are the same, heterozygous Icst elicits a phenotype whilst the null allele does not. Heterozygous Icst causes glaucomatous eye defects and is semi-lethal, probably due to kidney failure. We show that the null phenotype is rescued more effectively by an Lmx1b transgene than is Icst. Co-immunoprecipitation experiments show that both wild-type and Icst LMX1B are found in complexes with LIM domain binding protein 1 (LDB1), resulting in lower levels of functional LMX1B in Icst heterozygotes than null heterozygotes. We conclude that Icst is a dominant-negative allele of Lmx1b. These findings indicate a reassessment of whether nail-patella syndrome is always haploinsufficient. Furthermore, Icst is a rare example of a model of human glaucoma caused by mutation of the same gene in humans and mice.

Isolated diffuse episcleral neurofibroma.

AIMS: To report a rare case of isolated diffuse episcleral neurofibroma and to discuss possible differential diagnoses. CASE REPORT: A 37 year old Caucasian female was found to have an epibulbar tumour arising from the superior aspect of her left eye. Clinical examination revealed a 12 mm × 8 mm "salmon pink" coloured lesion. RESULTS: A biopsy was performed and histopathologic examination and subsequent systemic evaluation showed it to be a rare case of isolated diffuse episcleral neurofibroma. CONCLUSION: There are many differential diagnoses for an epibulbar lesion and neurofibroma should be added to these. Even though a small risk of malignant transformation exists, we recommend a conservative approach for slow growing lesions.