Nanophthalmos-Associated MYRF Gene Mutation Causes Ciliary Zonule Defects in Mice.

Purpose: Patients with nanophthalmos who undergo intraocular surgery often present with abnormal ciliary zonules. In a previous study, we reported mutation in MYRF that is implicated in the pathogenesis of nanophthalmos. The aim of this study was to model the mutation in mice to explore the role of MYRF on zonule structure and its major molecular composition, including FBN1 and FBN2. Methods: Human MYRF nanophthalmos frameshift mutation was generated in mouse using the CRISPR-Cas9 system. PCR and Sanger sequencing were used for genotype analysis of the mice model. Anterior chamber depth (ACD) was measured using hematoxylin and eosin-stained histology samples. Morphologic analysis of ciliary zonules was carried out using silver staining and immunofluorescence. Transcript and protein expression levels of MYRF, FBN1, and FBN2 in ciliary bodies were quantified using quantitative real-time PCR (qRT-PCR) and Western blot. Results: A nanophthalmos frameshift mutation (c.789delC, p.N264fs) of MYRF in mice showed ocular phenotypes similar to those reported in patients with nanophthalmos. ACD was reduced in MYRF mutant mice (MYRFmut/+) compared with that in littermate control mice (MYRF+/+). In addition, the morphology of ciliary zonules showed reduced zonular fiber density and detectable structural dehiscence of zonular fibers. Furthermore, qRT-PCR analysis and Western blot showed a significant decrease in mRNA expression levels of MYRF, FBN1, and FBN2 in MYRFmut/+ mice. Conclusions: Changes in the structure and major molecular composition of ciliary zonules accompanied with shallowing anterior chamber were detected in MYRFmut/+ mice. Therefore, MYRF mutant mice strain is a useful model for exploring pathogenesis of zonulopathy, which is almost elusive for basic researches due to lack of appropriate animal models.

Recurrent lacrimal gland choristoma of the ciliary body in an infant mimicking a medulloepithelioma.

PURPOSE: Choristoma is a congenital tumor made up of ectopic normal tissue. Different histopathologic subtypes have been described. Among them, lacrimal gland choristoma is found mainly in infants and can affect the iris, the ciliary body, or the choroid and epibulbar region. Our aims were to report a case of lacrimal gland choristoma, review the published cases, and present the main differential diagnoses. METHODS: A local resection of a limited mass of the ciliary body was performed on a 12-month-old girl who had a 6-month history of visual loss, leukocoria, and pupillary deformation. RESULTS: Histopathologically, we observed a well-demarcated lesion involved under the epithelium of the ciliary body. It was composed of acini delineated by a well-differentiated epithelium without atypia and mitotic figures. Immunohistochemical analyses confirmed the lacrimal nature with the expression of epithelial markers (cytokeratin 7 positive and cytokeratin 20 negative) and neuron-specific enolase without immunoreactivity for other neuronal markers. Two years later, a local recurrence appeared and was resected. It showed nearly the same histopathologic features. CONCLUSIONS: Lacrimal gland choristoma is a very rare lesion of the infant. Diagnosis is based on a histopathologic analysis with immunohistochemical studies to exclude other differential diagnoses such as a more common malignant tumor in childhood, medulloepithelioma. This observation shows an atypical clinical presentation of this benign lesion characterized by local recurrences.

Full-thickness sclerotomy for uveal effusion syndrome.

To report the surgical outcome of full-thickness sclerotomy in five cases of uveal effusion syndrome (UES). Full-thickness sclerotomy without sclerectomy was performed on five eyes of four patients with UES with or without nanophthalmos. In four of the eyes, exudative retinal detachment associated with UES resolved after the sclerotomy. The subretinal fluid in one eye, which had a normal axial length, was relieved after undergoing three sclerotomy procedures. Full-thickness sclerotomy without vortex vein decompression or sclerectomy is an effective surgical option for the management of significant UES.

Transscleral albumin diffusion and suprachoroidal albumin concentration in uveal effusion syndrome.

PURPOSE: To test the hypothesis that uveal effusion syndrome is caused by reduced transscleral albumin permeability. METHODS: Surgical scleral specimens were obtained from a 55-year-old patient with nanophthalmic uveal effusion syndrome. Specimens were clamped in a modified Ussing chamber, and the rate of transscleral diffusion of fluorescein isothiocyanate-albumin was measured over 12 hours, using a spectrophotometer and predetermined standard curves. The diffusion coefficient was determined at 20°C, and then adjusted to body temperature using Einstein's equation. Results in 3 scleral samples were compared with 10 age-matched controls. Albumin and total protein concentration were measured in choroidal fluid and serum. RESULTS: Histologic staining with Alcian blue showed interfibrillary acid mucin deposits. Transmission electron microscopy showed deposits measuring 1 µm to 10 µm and collections of expanded, degenerate collagen fibrils. The mean (±SD) albumin diffusion coefficient was 12% of that in controls (1.22 ± 0.67(-8) × 10 vs. 10.3 ± 7.0 × 10(-8) cm2/second) and below the lower 95% confidence limit of the control group. The diffusion coefficient was calculated to increase 53% to 1.87 ± 1.03 × 10(-8) cm2/second at 37°C. Choroidal albumin concentration was much higher than physiologic levels, measuring 200 g/L (total protein 321 g/L), 5 times the serum albumin concentration of 42 g/L (total protein 70 g/L). CONCLUSION: Nanophthalmic uveal effusion syndrome can be associated with reduced scleral permeability to albumin, and a very high concentration of retained suprachoroidal albumin. This will lead to an osmotic gradient that retains fluid and may partly explain the pathogenesis of uveal effusion syndrome in some patients.

Castleman's disease presenting with uveal effusion syndrome.

We report a rare case of multicentric Castleman's disease that presented with ophthalmic involvement, along with a review of the literature. A 63-year-old male presented with decreased visual acuity in both eyes. Both eyes had serous elevations of the retinas with shifting subretinal fluid and annular choroidal detachment. No retinal breaks were found. Laboratory tests revealed pancytopenia, hypergammaglobulinemia, and an increased erythrocyte sedimentation rate. Chest and abdominal computed tomographies showed multiple lymphadenopathies in the mediastinum, abdomen, and in both inguinal areas. Histological examination of the inguinal lymph node biopsy was consistent with Castleman's disease. After combination chemotherapy, the serous elevations of both retinas and the annular choroidal detachments of both eyes disappeared. Ophthalmic involvement in Castleman's disease is very rare, and to the authors' knowledge, this is the first report of ophthalmic involvement of Castleman's disease in Korea.

Fundus autofluorescence and spectral-domain optical coherence tomography findings of leopard spots in nanophthalmic uveal effusion syndrome.

PURPOSE: To describe fundus autofluorescence (FAF) imaging and spectral domain optical coherence tomography (SD-OCT) findings of leopard spots in nanophthalmic uveal effusion syndrome. METHODS: A 34-year-old man with retinal detachment associated with nanophthalmic uveal effusion syndrome in the right eye underwent sclerotomy three times. After the final surgery, the subretinal fluid resolved gradually. Then, SD-OCT examination, FAF photography, fluorescein angiography (FA), and indocyanine green angiography (ICGA) were performed simultaneously with the spectralis Heidelberg retina angiograph + OCT system. RESULTS: SD-OCT revealed focal thickening of the retinal pigment epithelium (RPE) layer at the same locations as leopard spots, which appeared hypofluorescent on FA and ICGA. These spots showed hyperautofluorescence on FAF imaging. Six months later, focal thickening of the RPE layer became smaller on OCT and hyperautofluorescence was attenuated on FAF imaging. CONCLUSIONS: Simultaneous imaging of the fundus with multiple modalities including OCT, FAF, FA, and ICGA indicates that leopard spots in the fundus of uveal effusion syndrome may show hyperautofluorescence and correspond to focal thickening of the RPE layer by SD-OCT. This imaging method may help elucidate the pathology of various fundus lesions in vivo.

Scleral punch method with topical mitomycin C for safe revision of failed deep sclerectomy in nanophthalmic uveal effusion syndrome.

PURPOSE: To describe a novel surgical technique for revision of deep sclerectomy surgery in nanophthalmic uveal effusion syndrome. METHODS: A 46-year-old woman with recessively inherited nanophthalmos and chronic uveal effusions underwent a revision of previous failed deep sclerectomy surgery. In the presence of scar tissue, revision of sclerectomies was greatly facilitated by the use of a Kelly scleral punch (Katena Products, Inc., Denville, NJ, USA). To inhibit further scarring, mitomycin-C (MMC) was applied topically in each quadrant posterior to the equator. RESULTS: The scleral punch allowed outward scleral dissection from the suprachoroidal space, and brisk enlargement of sclerectomies in all quadrants without perforation of choroidal tissue. Post-operative conjunctival wound healing appeared unimpeded by the posteriorly placed MMC sponges. Near-total resolution of the effusions had occurred by 3 months. CONCLUSIONS: The scleral punch provides a safe and effective method for constructing and revising full-thickness sclerectomies in the nanophthalmic eye, minimizing the risk of choroidal trauma. The use of topical MMC may reduce the risk of late failure of trans-scleral outflow due to fibrosis.

Scleral hydraulic conductivity and macromolecular diffusion in patients with uveal effusion syndrome.

PURPOSE: To determine whether uveal effusion syndrome (UES) is caused by altered scleral permeability to water and large molecules. METHODS: Transscleral water movement was measured using surgically removed sclera clamped in a modified Ussing chamber and connected to a water column set at intraocular pressure. Sclera was also clamped between two hemichambers, and transscleral diffusion of FITC-dextrans (4.4-77 kDa) was measured with a spectrophotometer. Clinical data were prospectively collected using postal questionnaires. RESULTS: Ten patients (mean age, 63 years; mean spherical equivalent, +4.7 D) had a median preoperative visual acuity of 0.20 that improved to 0.33 after surgery. Nine eyes showed visual improvement, three worsened, and two were unchanged. Histology showed disorganization of collagen fibrils, with amorphous deposits expanding the interfibrillary spaces. The mean thickness (+/-1 SD) of the excised scleral specimens was 585 +/- 309 microm, and the mean specific hydraulic conductivity was 23.9 +/- 27.5 x 10(-14) cm(2), compared with 5.8 +/- 3.9 x 10(-14) cm(2) in age-matched control specimens (P = 0.068). Three specimens had hydraulic conductivity above the 95% CI of the controls. Control eyes showed a significant reduction in diffusion coefficient (D) with age. Eyes had a mean D of 5.69 +/- 5.35 x 10(-8) cm(2) x s(-1), similar to control eyes (6.14 +/- 2.40 x 10(-8) cm(2) x s(-1), 20 kDa dextran). In one eye, the result was higher than the 95% CI of the control; in three, it was lower. CONCLUSIONS: UES is not caused by reduced scleral hydraulic conductivity, which tends to be higher than expected. Reduced macromolecular diffusion may impede the normal transscleral egress of albumin with subsequent osmotic fluid retention in some, but not all eyes.

Prevalence of ciliochoroidal effusion after prophylactic laser iridotomy.

PURPOSE: To study the prevalence of ciliochoroidal effusion (CE) after prophylactic laser iridotomy (LI). METHODS: An ultrasound biomicroscope (UBM) examination was performed before, 2, and 24 hours after LI to investigate the changes in supraciliary-choroidal space after LI in circumference of 38 eyes in 23 chronic primary angle-closure patients. Subjects were divided randomly into two groups based on LI settings: 21 eyes by argon laser (Ar-LI group) and argon combined with yttrium-aluminum-garnet (YAG) laser in 17 eyes (Ar-YAG-LI group). Ciliochoroidal effusion was observed predominantly in the inferior sector (12 of 12 eyes, 100%) and rare in nasal part of the eyes (4 of 12 eyes, 33%). Ciliochoroidal effusion appeared more often in the Ar-LI group (10 eyes, 52%) than in the Ar-YAG-LI group (2 eyes, 12%). All CE disappeared 7 days after by UBM observation. CONCLUSIONS: Subclinical CE observed by UBM frequently occurs after LI.

Age-dependent iris abnormalities in collagen XVIII/endostatin deficient mice with similarities to human pigment dispersion syndrome.

PURPOSE: Collagen XVIII is expressed in ocular basement membranes (BMs) and inactivating mutations cause Knobloch syndrome, with several ocular abnormalities. In this study we investigated ocular structures in collagen XVIII/endostatin (Col18a1(-/-))-deficient mice to elucidate the role of this extracellular matrix component in the eye. METHODS: Eyes of Col18a1(-/-) and control mice were examined by light and transmission electron microscopy, laser scanning ophthalmoscopy, and fluorescence angiography. Immunohistochemical analysis of neuronal, epithelial, and immune cells in the eye was performed with antibodies against established cell markers. RESULTS: Col18a1(-/-) mice showed a disruption of the posterior iris pigment epithelial (IPE) cell layer with release of melanin granules. The BM of the posterior IPE was attached to the lens and the nonpigmented epithelium of the ciliary body, which was flattened in mutant mice. In aged mutant mice a severe thickening of the stromal iris BM zone was found, and pigmented cells migrated out of the iris and covered the retina along the inner limiting membrane (ILM), sometimes penetrating into the retina. These cells resembled iris clump cells, and immunohistochemistry demonstrated that they were macrophage-like cells. Furthermore, morphologically abnormal retinal vasculature was seen by fluorescence angiography. CONCLUSIONS: The abnormalities in the iris and ciliary body of Col18a1(-/-) mice demonstrate an important role of collagen XVIII for the function of ocular BMs. The absence of this collagen alters the properties of BMs and leads to severe defects in the iris, showing striking similarities to human pigment dispersion syndrome. In addition, loss of collagen XVIII creates changes that allow clump cells to migrate out of the iris. These cells have not been well characterized previously. In the current study we showed that they are macrophage-like cells and are able to penetrate the ILM in mutant mice. The disease mechanism of human pigment dispersion syndrome is not well understood, but Col18a1(-/-) mice may serve as a model and demonstrate the potential importance of alterations in extracellular matrix components in this disease.

Immunocytochemical characterization of cysts in the peripheral retina and pars plana of the adult primate.

PURPOSE: To better characterize the cellular constituents of cysts in the peripheral retina and pars plana of the adult monkey. METHODS: Frozen sections of the peripheral retinal margin and pars plana from monkeys (Macaca nemestrina) between 1 and 15 years of age were stained with toluidine blue or immunolabeled with a variety of glia- and neuron-specific antibodies. RESULTS: In animals 1 to 2 years of age, the nonpigmented inner layer of the pars plana is a pseudostratified columnar epithelium. In these young animals, the peripheral retina had distinct layers and did not contain cysts. In animals 6 years of age or older, there were numerous cysts in the pars plana and in the peripheral retina. In the peripheral retina, neurons were randomly distributed and did not have a laminar organization. Cells surrounding cysts were immunoreactive for different types of markers for retinal neurons. Some of the cells surrounding cysts in the pars plana were also unexpectedly immunoreactive for antigens normally expressed only in retinal neurons and glia. CONCLUSIONS: Cysts form in the peripheral retina and pars plana in adult monkeys. The peripheral retinal cysts disrupt the normal lamination of the cells, but all types of retinal neurons are still present in the cysts. In an unexpected finding, cysts in the pars plana also contained cells immunoreactive for a few of the markers of retinal cells, suggesting that neurogenesis may occur in the pars plana of the adult primate.

A new approach to the surgical management of idiopathic uveal effusion syndrome.

PURPOSE: To describe a new method for managing retinal detachment associated with idiopathic uveal effusion syndrome. METHODS: A 73-year-old man with idiopathic uveal effusion syndrome and total retinal detachment in the right eye underwent quadrantic partial-thickness sclerectomies in conjunction with pars plana vitrectomy, internal drainage of subretinal fluid, and fluid-gas exchange. RESULTS: In the right eye, the patient's retina remained attached for 1 year after the procedure, and visual acuity improved to 20/70 on final follow-up. CONCLUSION: Internal drainage of subretinal fluid performed in conjunction with quadrantic partial-thickness sclerectomies may be a preferred method of treating secondary retinal detachment in idiopathic uveal effusion syndrome. This procedure hastens reattachment of the neurosensory retina and may thereby improve the visual outcome.

Lack of p53 protein immunoreactivity in bilateral diffuse uveal melanocytic proliferation.

BACKGROUND: Bilateral diffuse uveal melanocytic proliferation is a poorly understood disorder characterized by the progressive proliferation of uveal melanocytes associated with a systemic nonocular malignancy. Overexpression of p53 protein plays a role in the loss of regulatory control of normal cell proliferation, and p53 is the most commonly identified oncogenic protein in human malignancies. We tested the hypothesis that the aberrant cellular activity in bilateral diffuse uveal melanocytic proliferation involves the overexpression of p53 protein. METHODS: Eight eyes from four patients with bilateral diffuse uveal melanocytic proliferation were tested for p53 protein using an immunoperoxidase technique with an anti-p53 protein monoclonal antibody sensitive for normal and mutant p53 protein. RESULTS: The p53 protein could not be detected in any of the eight eyes. CONCLUSIONS: The proliferation of uveal melanocytes in bilateral diffuse uveal melanocytic proliferation does not depend on the overexpression of p53 protein. The loss of cellular regulatory control in bilateral diffuse uveal melanocytic proliferation is probably mediated through another mechanism.

[Retinitis pigmentosa with uveal effusion syndrome, a case report].

We reported a 65 year old female patient with retinitis pigmentosa accompanied by unilateral uveal effusion syndrome. Reduction in visual acuity and loss of depth of the anterior chamber were followed by peripheral choroidal detachment and then by retinal detachment. Subretinal fluid shifted to the lower part of the fundus for a short period and easily shifted to the posterior pole in a supine position. The axial length of both eyes was 21.3 mm. Fluorescein angiography revealed no definite points of leakage or abnormally dilated vessels. Chorioretinal detachment gradually disappeared with systemic steroid therapy. After that two recurrences, both of which were accompanied with loss of depth of the anterior chamber, we found during a follow-up period of two years. We thought this combination of retinitis pigmentosa and uveal effusion syndrome to be incidental. Since the exudative fluid easily accumulated in the subretinal space and shifted according to the head position, retinochoroidal adherence in retinitis pigmentosa may not be so strong as previously presumed.

Cataract surgery in nanophthalmic eyes.

Cataract surgery in nanophthalmic eyes may be complicated by postoperative uveal effusion. Evidence is presented that prophylactic lamellar scleral resection with decompression of the vortex veins, performed 2 months or more prior to cataract extraction, may reduce the incidence of this severe complication. A randomized study to determine the benefit of such prophylaxis is advocated.

The uveal effusion syndrome and trans-scleral flow.

Recent studies of the uveal effusion syndrome, a rare condition characterised by idiopathic spontaneous serous detachment of the retina and peripheral choroid, have suggested a primary scleral abnormality as the underlying cause. In particular, abnormal deposition of glycosaminoglycans within the sclera may impair normal trans-scleral flow of fluid and contribute to increased scleral thickness. In four cases of uveal effusion syndrome, we have confirmed the accumulation of glycosaminoglycans in the sclera. Histochemical studies show that most of this material is proteodermatan sulphate with a smaller contribution from proteochondroitin sulphate, while electron microscopy showed an increase in collagen fibril thickness. Secondary changes within the retinal pigment epithelium were also observed, particularly foci of proliferation which corresponded to the characteristic 'leopard-spot' fundal appearances of this disorder. We therefore suggest that the uveal effusion syndrome is due to a primary defect in proteodermatan synthesis and/or degradation by scleral fibroblasts and may represent a form of ocular mucopolysaccharidosis.