Retrobulbar Region Research Articles

Microphthalmia with a Large Orbital Cyst: A Case Report

Purpose: We present the case of a 4-month-old boy with a large orbital cyst that caused lateral displacement of the optic nerve resulting in progressive exophthalmos of the left eye since birth.Case summary: A 4-month-old boy presented with progressive exophthalmos of the left eye since birth. Physical examination revealed marked left eye proptosis. Magnetic resonance imaging revealed microphthalmia and a 2.2 × 1.9 cm orbital cyst in the retrobulbar region. Subsequently, an anterior orbitotomy of the left eye was performed to dissect and excise the cyst. Histopathological examination revealed an orbital cyst containing neuroectodermal tissue. No complications or recurrences were observed during the 3-month post-surgery period.Conclusions: Congenital microphthalmia with orbital cysts is a rare condition that does not always require surgical intervention. However, timely surgical intervention in cases of severe exophthalmos can result in favorable functional and cosmetic outcomes. We present a case that exhibited significant improvement following surgical removal of the orbital cyst.

GLIOMA-11 JUVENILE OLIGODENDROGLIOMA OF THE OPTIC NERVE: UNIQUE CASE REPORT AND CHALLENGE IN DIAGNOSIS ACCORDING TO CURRENT 2021 WHO CLASSIFICATION IN LIMITED RESOURCES COUNTRIES.

Abstract BACKGROUND The list of most commonly occurring primary brain tumors includes gliomas, and the vast majority of these are astrocytomas or oligodendrogliomas. Oligodendrogliomas, account for about 3% of all intracranial tumors and 20% of gliomas. They are more commonly found in adults and occur mainly in the superficial gray matter of the cerebral hemispheres. For this tumor, 69% of the lesion is located in the frontal lobes. Involvement of the hypothalamus and optic chiasm are rarely seen and the tumor is most rare within the eye itself. The positive stain of IHC stain GFAP and OLIGO-2 overexpression is required for confirmation of diagnosis. Molecular genetics study of IDH-mutant is used for WHO grading and management of the oligodendrogliomas lesions. CASE PRESENTATION A 10 years old male presented with progressive blurred vision for 2 years and left eye globe protrusion for 1 month. On examination, he present with keratopathy, loss of vision, and pus discharge on the left eye. The Brain MRI was done and showed a left orbital heterogeneous enhancing lesion with mixed cystic and soft tissue involving both the globe and retrobulbar region with associated distortion of the optic nerve. The eye globe enucleation was done and tissue samples were taken for histopathology. The histopathology diagnosis reveals the optic nerve oligodendroglioma (NOS). The patient was kept on 8 cycles of Carboplatin chemotherapy. CONCLUSION Definitive diagnosis of Juvenile Oligodendroglioma of the optic nerve can be made only after the results of pathological and immunohistochemical analyses are known. Also, the current WHO grading of Oligodendroglioma requires molecular genetics IDH study. Although Juvenile Oligodendroglioma of the optic nerve is extremely rare, preoperatively oligodendroglioma should be included in the differential diagnosis of optic nerve tumors in pediatrics especially in limited settings with no molecular IDH testing.

Can orbital artery resistive indexes detect complications of diabetes in the prediabetic phase?

Prediabetic patients have generalized microvascular dysfunction, which leads to end-organ damage, just like diabetes. Therefore, prediabetes is not just a mild elevation in blood sugar, and early detection and prevention of possible complications should be the main goal. Color Doppler imaging (CDI) provides morphologic and vascular information on various diseases. The Resistive Index (RI) is a widely used measure of resistance to arterial flow and is calculated from the CDI. CDI evaluation of vessels in the retrobulbar region may be the first sign of micro- and macrovascular complications. Consecutively, 55 prediabetic patients and 33 healthy subjects were recruited for the study. Prediabetic patients were divided into three groups according to their fasting and postprandial blood glucose values. The groups included an impaired fasting glucose (IFG) group (n = 15), an impaired glucose tolerance (IGT) group (n = 13), and an IFG+IGT group (n = 27). The RI of the ophthalmic artery, posterior ciliary artery, and central retinal artery were measured in all patients. The orbital artery, central retinal artery, and posterior cerebral artery mean RI of prediabetic patients (0.76 ± 0.06, 0.69 ± 0.03, and 0.69 ± 0.04, respectively) were significantly higher than those of the healthy group (0.66 ± 0.04, 0.63 ± 0.04, and 0.66 ± 0.04, respectively; p < 0.001; Student's t-test). The mean ophthalmic artery RI of the healthy, IFG, IGT, and IFG+IGT groups were 0.66 ± 0.39, 0.7 ± 0.27, 0.72 ± 0.29, and 0.82 ± 0.16, respectively, with a significant difference between the groups (p < 0.001, ANOVA). The mean central retinal artery RI of the healthy, IFG, IGT, and IFG+IGT groups were 0.63 ± 0.04, 0.66 ± 0.02, 0.7 ± 0.02, and 0.71 ± 0.02, respectively (p < 0.001, post-hoc Tukey). The mean posterior cerebral artery RI of the healthy, IFG, IGT, and IFG+IGT groups were 0.66 ± 0.04, 0.66 ± 0.04, 0.69 ± 0.03, and 0.71 ± 0.03, respectively, with a significant difference between the groups (p < 0.001 Fisher ANOVA). Increased RI may be the first sign of developing retinopathy, as well as the first sign of microangiopathies occurring simultaneously in the coronary, cerebral, and renal vessels. Precautions to be taken during the prediabetic stage can prevent many possible complications.

SADI-S with Extended Duodeno-Bulb Preservation: Case Report

Obesity has been growing in Brazil and in the world. It is reaching epidemic proportions, and bariatric surgery is the most effective treatment for patients with this disease. Among the procedures described in the literature, ileal surgeries such as biliopancreatic diversion with duodenal switch (BPD-DS) and single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) present better long-term results in terms of weight loss and comorbidities control. However, there are concerns regarding long term nutritional problems with these procedures. In this case report the aim is to demonstrate the technical feasibility of preserving an extended duodenal bulb segment, in the SADIS-S procedure, when there are difficulties in dissecting the retrobulbar region, as occurred here, due to fibrosis in this area. This assures the maintenance of the proposed surgical technique, in such a situation. The dissection and transection of the duodenum was done 7 cm distally to the pylorus, under endoscopic view, proximally to the papillae, where the tissue was normal. Additionally, due the importance of the duodenal mucosa on minerals and trace elements absorption and the release of important hormones in this region, this case report elicits the evaluation of the impact of this technical modification, which occurred casually, in the nutritional, hormonal and metabolic results, long term. In this case report, the extended duodenal length has demonstrated reasonable weight loss, adequate comorbidities control and good nutritional status, so far. These aspects must be evaluated in the long term, by clinical trials.

Bilateral blindness with a single bullet injury

Gunshot injuries are a rising concern, which can have ocular involvement in almost 2% of cases. We present a case of a 35-year-old woman with accidental gunshot injury with no perception of light Oculus Uterque (OU). OD had disk pallor and OS, a repaired corneoscleral perforation. The bullet entered the left orbit perforating the left globe, crossed over to the opposite side, and exited through the right temple. Noncontrast computed tomography (NCCT) head revealed comminuted fractures of the roof, lateral and medial orbital walls. Multiple tiny bony fragments and foreign bodies were seen in the retrobulbar region of OD in relation to the optic nerve near the optic disk. This case highlights that gunshot injuries to the eye have high morbidity, but they are largely preventable as most injuries are unintentional, as was seen in this case. The priority should be to spread awareness and sensitize the masses regarding preventive factors.

Ultrasound-guided retrobulbar nerve block in donkey cadavers

ObjectiveTo develop and describe an acoustic window to access and inject the retrobulbar region in donkey cadavers. Study designProspective cadaveric experimental study. AnimalsA total of 14 donkey cadaver heads. MethodsUltrasound landmarks for retrobulbar injection were identified by dissection of two cadavers. Ultrasound-guided retrobulbar injection of 3, 6 and 9 mL of contrast–lidocaine mixture (1:1) were evaluated using computed tomography (CT) in 12 cadavers for needle position and spread of injectate into the extraocular muscle cone. ResultsReal-time visualization of needle, extraocular muscle cone and optic nerve enabled successful intraconal instillation of injectate, as documented on CT images. Conclusions and clinical relevanceUltrasound-guided retrobulbar injections in cadaver donkeys provided adequate infiltration of the intraconal space.

A RARE CASE OF EXTRAOCULAR ORBITAL LYMPHOMA IN A YOUNG PATIENT

Orbital lymphoma refers to a lymphoma that commonly involves the conjunctiva, lacrimal gland, eyelid and ocular musculature. Primary non1 Hodgkin's lymphoma (NHL) of the orbit is a rare subset, representing only 1% of all NHL and 8-10% of extranodal NHL. We report a case of 24 year old female presented with redness, swelling, an intermittent pain and gradual protrusion of the right eye (RE) since 6 months. Her vision in RE was 6/60 and in Left eye (LE) 6/6. Intraocular pressure (IOP) was 16 mmHg in Both Eye. On examination, RE was proptosed 30mm approximately. Extraocular movement were restricted in all gazes, conjunctiva was chemosed and congested. LE was within normal limits. No lymph nodes were palpable. Ultrasonography of the right orbit showed a mass in the lateral aspect in extraconal space extending to the superior, lateral and retrobulbar region. CT scan of the right orbit showed a mass encasing the extraocular muscles and displacement of the optic nerve. FNAC reports were suggestive of non-Hodgkin's Lymphoma of the right orbit. She was given 6 cycles of RCHOP regime which includes (rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin and prednisolone). Follow-up during each cycle of chemotherapy was done and showed good response initially. Even though rare, primary orbital NHL should be kept in considerat Conclusion- ion in a young female patient with slow growing unilateral Proptosis. After imaging &amp; diagnostic biopsy, patient should be immediately staged &amp; treated. Early diagnosis and treatment improves survival.

Retrobulbar Cryptococcoma Mimicking Tumor in a Labrador Retriever

Background: Cryptococcosis is a systemic mycotic disease caused by encapsulated yeasts C. neoformans and C. gattii. Cryptococcus neoformans is predominantly found in soils and feces of pigeons and psittacids. Infection occurs mainly through the respiratory tract, through the inspiration of fungal propagules (basidiospores and/or desiccated yeast cells). The main lesions observed are in the nasal cavity and lungs, but in dogs, the central nervous system and eyes are widely affected. Despite some previously mentioned reports, the retrobulbar form has not been described in the literature. Therefore, the purpose of this report is to describe a case of retrobulbar cryptococcoma mimetizing a tumor in a young bitch. Case: A 2-year-old female Labrador Retriever, was admitted to one Veterinary Hospital with exophthalmia on the left eye for 15 days and other signs included negative retropulsion, mydriasis, and abscence of menace and pupillary reflexes. Ocular ultrasound imaging revealed a hyperecotic and heterogeneous retrobulbar mass in the mid-dorsal region compressing the optic nerve. Computed tomography of the skull showed the presence of proliferation of neoplastic tissue in a locally invasive retrobulbar region promoting moderate rostrolateral displacement of the left ocular bulb, discrete osthelysis in maxillary bone, palatine, medial wall of the orbital bone and frontal bone, with destruction of cribiform plate adjacent to the dorsal region of the orbital wall and presence of mild contrast uptake in the region of the left olfactory bulb lobe, characterizing a picture compatible with neoplasia with malignancy and locally invasive characteristics. Exenteration and excision of part of the frontal bone were performed and histopathological examination revealed granulation with the presence of fibroblasts and numerous typical blastoconidia of Cryptococcus neoformans. The patient was treated with Itraconazole [10 mg/kg, v.o, SID, for 90 days] and one year after diagnosis, X-ray was performed to control the lesion and radiographic aspects were within normal limits.Discussion: Cryptococcus sp. is an environmental fungus that has the potential to be pathogenic to humans and animals. Fungus present as a basidiospores in pigeon droppings. The patient described had a history of contact with free-living pigeons, making it a risk factor for the occurrence of cryptococcosis, being the possible cause of the infection. In dogs, the disease is mainly described in immunosuppressed animals, which was not the case of the patient, who presented clinical and laboratory results within the normal range and without a previous history of use of immunosuppressants. The alterations described in the computed tomography, such as destruction of the cribriform plate adjacent to the dorsal region of the left orbital wall and the presence of slight contrast uptake in the left olfactory bulb lobe region, are compatible with the main entry point for propagules of Cryptococcus sp. In the present case, no periocular and ocular alterations were observed as described in the literature, and the lesion was restricted to the retrobulbar space. Ultrasonography and computed tomography revealed a neoformation mimicking a malignant neoplasm and the diagnosis of cryptococcoma was revealed by histopathology. Based on the present case, cytology through aspiration of retrobulbal neoformations is imperative as a diagnostic method, especially in endemic areas for fungal diseases that can mimic ocular neoplasms. Keywords: cryptococcosis, fungus, Cryptococcus sp., dog. Descritores: criptococose, fungo, Cryptococcus sp., cão.

Urothelial bladder carcinoma metastasizing to the eye: A systematic review and case report.

The eye is a rare site for disseminated malignancies; nevertheless, several tumors may metastasize to ocular structures. Few cases of urothelial and bladder cancer with eye involvement have been described in the literature thus far. The rarity of metastatic ocular localization implies an accurate differential diagnosis among the possible primary tumor sites. However, a specific diagnostic algorithm is not currently available, nor a defined therapeutic approach. Eye metastases are associated with advanced disease and poor prognosis. Physicians should be made aware of the possibility of eye involvement in patients with a past medical history of urothelial bladder cancer associated with ocular symptoms. The present case reports discusses the first documented case, to the best of our knowledge, of an urothelial bladder cancer metastasizing to the retro bulbar region that infiltrates the lacrimal gland. Furthermore, the report provides a systematic qualitative review of the current literature on eye metastases from urothelial bladder cancer using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Contrast-enhanced ultrasonography for evaluation of blood perfusion in normal canine eyes.

This study was performed to evaluate ocular structures using contrast-enhanced ultrasonography (CEUS) in dogs to assess the feasibility of CEUS for investigating the blood perfusion of canine eyes. Eight purpose-bred beagles were used. Blood perfusion and vascularity of the right eye were evaluated using color Doppler, power Doppler, and CEUS with Sonazoid® . Vascular changes were quantitatively evaluated by measuring peak intensity, time to initial upslope, and time to peak from the ciliary body, iris, choroid, retina, and the retrobulbar region by CEUS. On CEUS images, all parts of the examined ocular structures were markedly enhanced and clearly identified from the adjacent region. After injection, the contrast agent initially flowed to the choroid and retina at 14.2seconds, then to the ciliary body and iris at 20seconds. The blood signal reached its peak intensity in the ciliary body at 27.2seconds (47.4±10.63), in the iris at 31.6seconds (74.00±41.85), and in the retrobulbar region at 23.4seconds (149±24.59). The optic nerve was clearly distinguished from the retrobulbar region over 5minutes after the initiation of CEUS. Significantly, more vascular signals were detected in the ciliary body and iris by CEUS than by color and power Doppler. Blood perfusion of the intraocular structures and the retrobulbar region can be quantitatively and qualitatively analyzed by CEUS. CEUS may be a useful, noninvasive, and sensitive tool for the evaluation of blood perfusion in ocular diseases.

Prospective study of ocular and periocular diseases in animals: 188 cases

ABSTRACT: Histopathology of the ocular and periocular tissues submitted for diagnosis and research is still incipient in Brazil, in contrast to veterinary clinical ophthalmology. In this study, ocular and periocular tissues from domestic and wild animal species, mainly from the state of Minas Gerais, Brazil, were evaluated between February 2012 and September 2015. The samples were analyzed grossly and microscopically. Histochemistry and immunohistochemistry were performed on some of the samples. The frequency, type of ocular alteration, affected animal species, and affected ocular or periocular tissues were recorded. One hundred eighty-eight ocular and periocular tissues from domestic and, occasionally, wild animals were examined. Nine animals presented two concurrent alterations, adding up to 197 alterations. Proliferative lesions were the most frequent (92), followed by traumatic (43), inflammatory (37), degenerative (18), developmental (4) and vascular/hemorrhagic diseases (3). The globe was the most affected structure (112), followed by eyelids (52), third eyelid (17), bulbar conjunctiva (14) and retrobulbar region (2). Neoplasms arising from periocular tissues were the most frequent alteration (60), possibly related to a more active surgical service and histopathologic evaluation request. Many animals presented ocular lesions that reflected systemic diseases, which were diagnosed by necropsy and examination of other organs. Particularly in cases of neoplasia, early detection and surgical treatment can prevent systemic involvement. Ocular histopathologic evaluation can provide better characterization and prognosis of the clinical-pathological condition of the patient as well.

Abordagem de tumor intra-orbitário pelo acesso supra-orbital sinusal

Descreve-se a técnica de acesso à órbita pelos seios frontais (acesso supra-orbital sinusal) para abordagem de lesões intra-orbitais localizadas no ápice e na região póstero-medial da órbita. Esse acesso é realizado sem orifícios de trépano, possibilitando melhor resultado cosmético. A parede anterior dos seios frontais é remoida juntamente com a porção ântero-medial do teto da órbita. É descrito um caso em que essa técnica foi utilizada.

Pleomorphic adenoma of retrobulbar ectopic lacrimal gland: a rare occurrence

Ectopic lacrimal gland encompasses all lacrimal tissue that is outside the lacrimal gland fossa, excluding the accessory glands of Krause and of Wolfring. The bulbar conjunctiva and limbus are most commonly involved regions while retrobulbar region is unusual. This tissue may undergo neoplastic transformation, the commonest tumour being pleomorphic adenoma. A 30 year old male presented with painless loss of vision and mild proptosis of the right eye since 5 months. MRI disclosed a well-defined, lobulated contrast enhancing mass in the right retrobulbar region measuring 2 X 2 X 2 cm and a differential diagnosis of vascular or glial neoplasm was entertained. Excision biopsy revealed an encapsulated mass away from the lacrimal fossa. Histopathology showed features of pleomorphic adenoma which was confirmed on IHC.

Surtos de conidiobolomicose ovina por Conidiobolus lamprauges no Estado da Bahia, Nordeste do Brasil

The present work describes the occurrence of two conidiobolomycosis outbreaks in Santa Ines breedsheep, in the state of Bahia. The first outbreak (FO) occurred in a property located in Santo Estevao city,involving three animals, and the second outbreak (SO) occurred in a property in Entre Rios city, affecting one sheep. In both outbreaks, the clinical findings were characterized by progressive weight loss, dyspnea, andbloody serous nasal discharge. In the FO was also observed unilateral craniofacial asymmetry, associatedwith exophthalmia and epiphora of the right eye. Autopsies performed on the three FO sheep showeda large mass predominantly yellowish-white with red-black areas of the uneven surface, finely granular,moist and crumbly located in the ethmoidal region, invading the nasopharyngeal, choana, sinuses, retrobulbar region, who infiltrated the cribriform plate and reached the meninges. In two sheep of the FO, themass reached the front portion of the brain. In SO sheep it was found, on the mucous membrane of thenasal vestibule, small red-black multifocal to coalescing nodules, with eroded surface and hyperemiaof the nasal turbinates with hemorrhagic catarrhal secretion, and in the most rostral portion of nasalcavity, the mucosa had a irregular, wet, bleeding and red-black surface, with blackish gray and brownishareas, displaying partial focal destruction of nasal turbinates. Microscopic examination of granulomatouslesions revealed multiple areas of coagulation necrosis containing intense reaction of Splendore-Hoeppliassociated with negative images of fungal hyphae and granulomatous inflammation. In all cases, theGMS and PAS staining showed numerous wide hyphae, with bulbous distension at one end. By PCRtechnique it was characterized Conidiobolus lamprauges by analysis of serum samples of two sheep andparaffin block lesions of one sheep. Immunohistochemical analyzes were positive for C. lamprauges inall animals. It can be proved, for the first time, the occurrence of nasopharyngeal / rhinocerebral andrhinofacial conidiobolomycosis infection by C. lamprauges in the state of Bahia.

Orbital multilobular osteochondrosarcoma in a dog

Retrobulbar tumors may arise from any orbital tissue. Some are primary and others may extend from adjacent structures or derived from metastases. Multilobular osteochondrosarcomas are regarded as slowly growing and potentially malignant neoplasms in dogs. This tumor is of rare occurrence on retrobulbar region. This paper aims to report a rare case of female dog, Shih Tzu, spayed, five-year-old, that was referred to the Hospital of Veterinary Medicine, Federal University of Bahia, Brazil, with an increased volume in the orbital space, after enucleation for exophthalmia of unknown etiology. This animal was evaluated clinic and the diagnosis image (radiography and computed tomography) demonstrated a large formation of bone predominantly in the region of the right orbit and zygomatic arch, with invasion and destruction of adjacent bones. Due to her poor quality of life, the dog was submitted to euthanasia and after necropsy. On gross examination, an encapsulated nodular mass with an irregular surface, measuring 5.6 x 4.6 x 3.9 cm, was located in the right lateral skull, occupying the orbit with displacement of the zygomatic arch. The tumor was identified by histopathology as a malignant mesenchymal neoplasm, multilobular osteochondrosarcoma. Thus, differential diagnoses for exophthalmos should include cancers, including the multilobular osteocondrossarcoma.

A difficult surgical approach for primary orbital hydatid cyst: transconjunctival medial orbitotomy

Hydatid cysts rarely appear isolated in the orbital cavity without involvement of other organs. The cysts are usually located in the retrobulbar region, and may be extraconal or intraconal. Herein we present a case of primary orbital cyst hydatid that is adjacent to the medial rectus muscle and optic nerve in the intraconal space and the difficulties during the surgical and medical treatment period.

Mechanism study on trans-lamina cribrosa pressure difference correlated with optic neuropathy in glaucoma

Glaucomatous optic neuropathy is among the most common causes of blindness worldwide. Elevated intraocular pressure (IOP) has long being considered to be the major risk factors for the development and progression of glaucomatous optic nerve damage. However, numerous studies have shown that a relatively large number of patients with typical glaucomatous optic neuropathy, in whom the IOP measurements have always been in the normal range (<21 mmHg, 1 mmHg = 0.133 kPa). Thus, the role of IOP in the pathogenesis of POAG becomes vague and controversial. Based on prospective clinical observations, Beijing iCOP (Intracranial and Intraocular Pressure) Study has found that the orbital cerebrospinal fluid pressure (CSF-P) may be of importance for the physiology and patho-physiology of the optic nerve head and may play a role in the pathogenesis of glaucomatous optic neuropathy. A low CSF-P in the retrobulbar region of the orbit may act as the counter-pressure against IOP and theoretically have a similar effect as an increased IOP on the trans-lamina cribrosa pressure difference which may be more relevant to the glaucomatous optic neuropathy than IOP alone. Moreover, an experimental and chronic reduction in CSF-P in monkeys was associated with the development of optic nerve damage morphologically typical for glaucomatous optic neuropathy. The findings support the hypothesis the CSF-P may play a role in the pathogenesis of glaucomatous optic neuropathy.

Internal Carotid Artery Dissection and Asymmetrical Facial Flushing

A 47-year-old woman presented to her primary care physician (PCP) with severe left-sided headache localized in the retrobulbar and temporal region. The PCP suspected migraine and prescribed a nonsteroidal anti-inflammatory drug. But despite analgesic treatment, her headache continued, and she returned to her PCP 2 weeks later. At this visit, the PCP noticed new anisocoria with a miotic pupil on the left. Emergent magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of neck and brain revealed no acute or subacute cerebral lesions but a narrowing and semicircular wall hematoma of the left internal carotid artery (ICA) up the petrous segment (Figure 1). The wall hematoma resulted in almost complete occlusion of the arterial lumen. Hereafter, she was transferred to our stroke center, where we confirmed diagnosis of ICA dissection with incomplete Horner syndrome. Figure 1. A , T2-TIRM (turbo inversion recovery magnitude) dark fluid MRI, axial slices; this sequence shows the typical intramural hematoma in the left ICA (arrow). B , T1 TSE (turbo spin echo) with fat saturation, coronal slices; use of fat-saturation technique shows bright (met-hemoglobin containing) hematoma in the left ICA below the scull base. Extracranial and intracranial duplex sonography revealed a resistance flow profile in the dissected ICA indicating distal occlusion. Collateral circulation through the left posterior communicating artery maintained the blood flow in the left anterior and middle cerebral artery. Six days later a repeated ultrasound showed improving blood flow with only local flow accelerations in the distal extracranial portion of the dissected ICA. The patient was treated with aspirin 300 mg daily for 2 weeks followed by a dose reduction to 100 mg daily. During hospitalization, she remained clinically stable and was discharged home after 8 days. At …

Nonneuronal Control of the Differential Distribution of Myelin Along Retinal Ganglion Cell Axons in the Mouse

In most mammalian species, retinal ganglion cell (RGC) axons are myelinated in the optic nerve, but remain nonmyelinated in the retinal nerve fiber layer and the most proximal (i.e., retina-near) region of the nerve. Here we analyzed whether RGCs are involved in the control of this characteristic distribution of oligodendrocytes and myelin in the primary visual pathway of mice. Neurospheres were enriched in oligodendrocyte progenitor cells (OPCs) by a short-term exposure to platelet-derived growth factor (PDGF) and grafted into the retina of young postnatal mice close to the optic disc. Immunohistochemistry was performed to study the integration and differentiation of the grafted cells, and the formation of donor-derived myelin in the normally nonmyelinated retinal nerve fiber layer and intrabulbar and most proximal retrobulbar region of the optic nerve. Intraretinal transplantations of small-sized PDGF-treated neurospheres into young postnatal mice resulted in extensive integration of the grafted cells into host retinas. A significant fraction of the donor cells differentiated into oligodendrocytes that myelinated the nerve fiber layer. Importantly, RGC axon segments within the normally nonmyelinated intrabulbar and most proximal retrobulbar region of the nerve also became myelinated in a fraction of animals. This is the first report demonstrating that the normally nonmyelinated intrabulbar and retrobulbar segments of RGC axons are competent to become myelinated. Results support the view that the differential distribution of myelin and oligodendrocytes in the primary visual pathway is controlled by nonneuronal factors rather than by the RGCs themselves.

Recurrent neurofibroma of the orbit

A 55-year-old male patient presented with gradual progressive outward and downward deviation of right eye since last two years, with history of a similar complaint 10 years ago when he was diagnosed as having neurofibroma of the orbit. Computed Tomography imaging revealed a large, multilobulated, heterogeneous, soft tissue density mass lesion in the retro bulbar region on the medial side of right orbit suggestive of a neurofibroma. Excision and histopathology confirmed it to be a recurrence of neurofibroma of the orbit.