SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY EVIDENCE OF RETINAL NERVE FIBER LAYER AND GANGLION CELL LOSS IN ADULT PATIENTS WITH NEUROFIBROMATOSIS TYPE 1

A novel stop-gain NF1 variant in neurofibromatosis type 1 and bilateral optic atrophy without optic gliomas

BACKGROUND

Neurofibromatosis type 1 (NF1) is a multisystem disorder that primarily affects the skin and peripheral nervous system and is caused by chromosomal abnormalities and mostly truncating variants in the NF1 gene. Ocular complications such as Lisch nodules and optic pathway gliomas (OPGs) can occur in NF1 patients. Herein, we report a novel NF1 variant in an NF1 patient with bilateral optic atrophy.

METHODS

Ophthalmological examinations and genetic analyses were performed using targeted next-generation sequencing (NGS).

RESULTS

A 14-year-old girl diagnosed with NF1 visited our hospital with decreased visual acuity (VA). The patient had no family history of NF1 or visual impairment. Brain and orbital magnetic resonance imaging revealed no remarkable findings. Ophthalmoscopy revealed temporal pallor of the optic discs, which was confirmed by optical coherence tomography findings of significant thinning of the circumpapillary retinal nerve fiber layer in both eyes. At 23 years of age, the decimal-corrected VA had deteriorated to 0.2 in the right eye and 0.1 in the left eye. Additionally, the targeted NGS panel revealed a novel heterozygous stop-gain variant (p.Tyr628Ter) in the NF1 gene; however, no pathogenic variants in OPA1 or the mitochondrial DNA were identified.

CONCLUSIONS

A patient with NF1 without OPGs developed bilateral optic atrophy and carried a novel de novo stop-gain variant of NF1. Although the relationship between NF1 variants and bilateral optic atrophy remains unclear, further investigations are required.

Insights into Novel Choroidal and Retinal Clinical Signs in Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a rare inherited neurocutaneous disorder with a major impact on the skin, nervous system and eyes. The ocular diagnostic hallmarks of this disease include iris Lisch nodules, ocular and eyelid neurofibromas, eyelid café-au-lait spots and optic pathway gliomas (OPGs). In the last years, new manifestations have been identified in the ocular district in NF1 including choroidal abnormalities (CAs), hyperpigmented spots (HSs) and retinal vascular abnormalities (RVAs). Recent advances in multi-modality imaging in ophthalmology have allowed for the improved characterization of these clinical signs. Accordingly, CAs, easily detectable as bright patchy nodules on near-infrared imaging, have recently been added to the revised diagnostic criteria for NF1 due to their high specificity and sensitivity. Furthermore, subclinical alterations of the visual pathways, regardless of the presence of OPGs, have been recently described in NF1, with a primary role of neurofibromin in the myelination process. In this paper, we reviewed the latest progress in the understanding of choroidal and retinal abnormalities in NF1 patients. The clinical significance of the recently revised diagnostic criteria for NF1 is discussed along with new updates in molecular diagnosis. New insights into NF1-related neuro-ophthalmic manifestations are also provided based on electrophysiological and optical coherence tomography (OCT) studies.

Correlation Between Ophthalmologic and Neuroradiologic Findings in Type 1 Neurofibromatosis

BACKGROUND

Neurofibromatosis Type 1 (NF-1) is a genetic disease affecting the eye, and ocular findings such as Lisch nodules (LN) or optic pathway gliomas (OPGs) are a part of its diagnostic criteria. Recent imaging technologies such as infrared (IR) imaging and optical coherence tomography (OCT) have highlighted the visualization of choroidal focal abnormalities in these patients, even in the absence of other ocular lesions. This study aimed to establish a morphological multimodal evaluation of choroidal findings in patients with NF-1, correlating them with central nervous system (CNS) findings.

METHODS

This retrospective study included 44 eyes from 22 patients with NF-1. Central 30° IR imaging was obtained, and the number and total area of detectable lesions were calculated. Both macular and optic disc scanning with OCT were performed, with and without the enhanced depth imaging technique, to assess the presence of choroidal focal hyperreflective lesions. Central macular thickness, ganglion cell layer, and outer nuclear layer thickness were assessed, as well as subfoveal choroidal thickness. The peripapillary retinal nerve fiber layer (RNFL) thickness was also assessed. Patients' magnetic resonance images (MRI) were reviewed and categorized by a neuroradiology specialist, determining the presence of OPGs and CNS hamartomas. Correlations between the ophthalmological and neuroradiological findings were established.

RESULTS

Patients' mean age was 16.4 ± 7.3 years and 59.1% were women. On the MRI, 86.4% of the patients had CNS hamartomas, and 34.1% of the eyes had OPGs. LN were described in 29.5% of the eyes, whereas a total of 63.4% of the eyes presented the characteristic hyperreflective lesions in IR imaging, all of them matching the underlying choroidal lesions. A mean of 2.9 ± 3.3 lesions per eye and a median total lesion area of 1.52 mm2 were found. The presence of OPGs was correlated with a greater number (P = 0.004) and a larger area (P = 0.006) of IR lesions. For a cut-off of 3.5 lesions per eye, the sensitivity and specificity for the presence of OPGs were 75% and 80%, respectively. For a total lesion area of 2.77 mm2, the sensitivity and specificity for the presence of OPGs were 69.2% and 93.1%, respectively. Eyes with OPGs presented a significant reduction in the temporal RNFL (P = 0.018) thickness, as well as a reduction in subfoveal choroid thickness (P = 0.04). No relations were found between CNS hamartomas and ophthalmological findings.

CONCLUSIONS

This study suggests that focal choroidal abnormalities are correlated with the presence of CNS lesions as OPGs in patients with NF-1, and it might be a surrogate for the need for CNS imaging in these patients.

Ocular Manifestations of the Sturge-Weber Syndrome

Sturge-Weber syndrome (SWS) or encephalotrigeminal angiomatosis is a non-inherited congenital disorder characterized by neurologic, skin, and ocular abnormalities. A somatic activating mutation (R183Q) in the GNAQ gene during early embryogenesis has been recently recognized as the etiology of vascular abnormalities in SWS. Approximately, half of the patients with SWS manifest ocular involvement including glaucoma as the most common ocular abnormality followed by choroidal hemangioma (CH). The underlying pathophysiology of glaucoma in SWS has not been completely understood yet. Early onset glaucoma comprising 60% of SWS glaucoma have lower success rates after medical and surgical treatments compared with primary congenital glaucoma. Primary angle surgery is associated with modest success in the early onset SWS glaucoma while the success rate significantly decreases in late onset glaucoma. Filtration surgery is associated with a higher risk of intraoperative and postoperative choroidal effusion and suprachoroidal hemorrhage. CH is reported in 40-50% of SWS patients. The goal of treatment in patients with CH is to induce involution of the hemangioma, with reduction of subretinal and intraretinal fluid and minimal damage to the neurosensory retina. The decision for treating diffuse CHs highly depends on the patient's visual acuity, the need for glaucoma surgery, the presence of subretinal fluid (SRF), its chronicity, and the potential for visual recovery.

Ocular biometric parameters changes and choroidal vascular abnormalities in patients with neurofibromatosis type 1 evaluated by OCT-A

Purpose

To analyze ocular biometric parameters alterations of the posterior pole and choroidal abnormalities in patients with neurofibromatosis type 1 (NF1) by adopting multimodal imaging, especially focusing on the role of novel diagnostic devices like swept-source optical coherence tomography angiography (SS-OCTA).

Methods

In this prospective, case-controlled study, patients with NF1 and age-matched control subjects were quantitatively analyzed by using multimodal imaging. All the subjects underwent confocal scanning laser ophthalmoscopy (SLO), SS-OCT and SS-OCTA examinations.

Results

SS-OCT analysis revealed a lower macular retinal nerve fiber layer (RNFL) thickness in patients with NF1 compared with those with suspected NF1 (95.0±15.9 vs 109.7±11.3 μm; P = 0.001) and control subjects (106.8±14.4 μm, P = 0.003). Retinal thickness was significantly lower in NF1 patients compared to those with suspected NF1 (280.7±23.0 vs 304.2±15.3 μm; P < 0.001) and control subjects (298.7±23.8 μm, P = 0.003). The mean vascular flow area of the SCP was significantly higher in patients with NF1 (42.6±2.2%) and suspected NF1 (43.1±2.5%) compared to control subjects (41.0±2.0%; respectively, P = 0.017 and P = 0.002). In the second choroidal layer, the flow area was significantly lower in patients with NF1 compared to control subjects (45.4±4.8 vs 49.0±4.0%,; P = 0.011).

Conclusions

Retinal thicknesses alterations and choroidal nodules are described as ocular manifestations in patients with NF1. In addition, OCTA could represent an important novel advanced imaging technique, capable of detecting early altered retinal and choroidal vascular flow area in patients with NF1.

Current concepts on ocular vascular abnormalities in the phakomatoses

BACKGROUND

Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular abnormalities such as vascular tortuosity, corkscrew retinal vessel configuration, moyamoya-like aspect, microaneurysms, hemangioblastomas, and focal sheathing of retinal arteries, possibly due to abnormal formation, migration, and differentiation of neural crest cells. These alterations can be the first sign or the hallmark of disease and can be related to vasoproliferative tumors.

PURPOSE

Novel imaging technologies in ophthalmology, such as near-infrared reflectances and spectral domain optical coherence tomography, have improved our knowledge in the diagnosis of these pathologies. Previously undetected macular vascular alterations have been reported in phakomatoses using optical coherence tomography angiography. This review will summarize the ophthalmic vascular abnormalities and novel imaging methods in the phakomatoses.

CONCLUSION

Active research is being led into the ophthalmic management of these conditions and their complications, and owing to elevated vascular endothelial growth factor production from hemangioblastoma, hamartoma, and retinal vascular proliferative tumors, increasing interest in this line of therapy has been conducted although research is still ongoing in this area.

Long-term follow-up of adult patient with neurofibromatosis type 1 with retinal astrocytic hamartoma using spectral-domain optical coherence tomography: a review of the literature and a report of a case

Background: Retinal astrocytic hamartoma (RAH) is a tumor that can be sporadic or in the context of tuberous sclerosis complex (TSC) and has been reported to be associated with neurofibromatosis type 1 (NF1) in a few cases.Patient and methods: A 65-year-old male patient with NF1 was referred for ophthalmological evaluation. Comprehensive examination, near-infrared reflectance (NIR), spectral-domain optical coherence tomography (SDOCT), fluorescein angiography (FFA), and indocyanine green angiography (ICGA) were carried out. The follow-up of the patient was at 4 and 7 years.Results: Best-corrected visual acuity (BCVA) was 20/20 in both eyes. Anterior segment examination revealed bilateral Lisch nodules. Fundus examination was unremarkable but at NIR and SDOCT the patient presented choroidal hamartoma, microvascular retinal alterations, and enlarged choroidal vessels in both eyes. NIR also revealed an unusual area of peripapillary hyporeflectivity in the right eye. On SDOCT, this corresponded to an elevated peripapillary mass characterized by intralesional optically empty cavities in the retinal nerve fiber layer (RNFL) and ganglion cell layer-inner plexiform layer (GCL-IPL), diagnosed as a RAH. Four years later, BCVA was 20/25 with a retinal schisis departing from the lesion to the macula. At 7 years, BCVA was stable at 20/25, the lesion was smaller, and there was a slight reduction of the schisis.Conclusion: RAH is a rare finding in NF1 and the translucent type has not been previously reported. RAH in NF1 has a peripapillary location and demonstrates clinically unpredictable behavior; thus, close monitoring with multimodal imaging is advisable.

Ocular manifestations in phakomatosis pigmentovascularis: Current concepts on pathogenesis, diagnosis, and management

Phakomatosis pigmentovascularis is a rare congenital multisystemic disease with variable manifestations where a vascular malformation of the skin is associated with a pigmentary nevus. Ocular involvement includes glaucoma, choroidal hemangioma, and pigmentary alterations that predispose to uveal melanoma. Diagnosis is made on clinical grounds, although recent advances in molecular genetics have better clarified the etiopathogenesis of the condition. The advent of improved imaging techniques such as enhanced depth imaging spectral domain optical coherence tomography has provided new insight into the ocular alterations, enabling better follow-up of patients. We review the ophthalmic manifestations of the disease with an update on etiopathogenesis and current management strategies.

Unusual Case of Indolent Choroidal Alterations Mimicking Neurofibromatosis Type 1

Indolent, non-progressive choroidal alterations can be strongly suggestive of neurofibromatosis type 1 (NF1) but are also rarely of unknown aetiology. A 63-year-old man presented for a routine examination. Comprehensive ophthalmological examination and retinal imaging was performed. Visual acuity was 20/20. The anterior segment and fundus were unremarkable. Near-infrared reflectance (NIR) with spectral-domain optical coherence tomography showed unilateral hyperreflective areas in the left posterior pole, corresponding to choroidal nodules on enhanced depth imaging and hypofluorescent areas on indocyanine green angiography. Dermatological evaluation and genetic testing for NF1 were negative. Chest computed tomography, liver function, HLA-A29, and angiotensin-converting enzyme level were negative. The patient has remained in good health and the choroidal alterations have remained non-progressive for 3 years. Choroidal alterations observed with NIR could be a manifestation of somatic mosaicism or a variation of a new unclassified correlated condition that may be better elucidated in the future, given the use of novel imaging techniques that are currently available in ophthalmology.

Homonymous Retinal Ganglion Cell Layer Atrophy With Asymptomatic Optic Tract Glioma in Neurofibromatosis Type I

Approximately 20% of patients with Neurofibromatosis type 1 (NF1) develop optic pathway gliomas (OPGs). Not all OPGs in NF1 necessarily become vision compromising and predicting which patients might develop visual decline is difficult at present time. Optical coherence tomography (OCT) has emerged as a useful tool able to directly assess the morphology and thickness of individual retinal layers. The ganglion cell layer (GCL) is composed of the retinal ganglion cells which receive information from photoreceptors via interneurons, while the retinal nerve fiber layer (RNFL) contains the retinal ganglion cell unmyelinated axons that merge to form the optic nerve. Lesions of the anterior visual pathway result in retrograde axonal degeneration from ganglion cell death and ultimately manifest as thinning of the RNFL and/or GCL. In this report we highlight a case of a 38 year-old woman with an NF1 associated left chiasmal and optic tract glioma who had normal visual fields and visual acuity. However, using OCT we demonstrate a homonymous pattern of GCL atrophy that corresponds with her left optic tract glioma. Given this homonymous pattern of atrophy in the GCL and the left optic tract lesion, one would expect a right homonymous hemianopia. To our knowledge this is the first reported case of a homonymous pattern of GCL-IPL atrophy in an adult with an NF1 related OPG involving the optic chiasm and optic tract, but without objective visual field or acuity deficits. This case is important because, mechanistically, it suggests that a necessary threshold of GCL atrophy may be needed before visual concerns can be detected and, secondly, it invites future studies to evaluate whether OCT may serve as a potential screening tool for those with NF1 related OPGs.

Bilateral diffuse choroidal hemangioma in Sturge Weber syndrome: A case report highlighting the role of multimodal imaging and a brief review of the literature

PURPOSE

To present a patient with bilateral choroidal hemangioma in Sturge-Weber syndrome (SWS) and highlight multimodal imaging techniques for early detection and management of ocular alterations.

METHODS

A 37-year-old woman with diagnosis of SWS presented to our unit. The patient had been treated with pulsed dye laser for bilateral nevus flammeus and had right leptomeningeal angiomatosis. She had glaucoma, but ultrasound biomicroscopy did not show anterior chamber or ciliary body alterations.

RESULTS

Enhanced depth imaging (EDI) spectral domain optical coherence tomography (SD-OCT) showed bilateral diffuse choroidal hemangiomas in both eyes with choroidal thickness above 1000 μm. B-scan ultrasound examination showed diffuse choroidal hemangioma in both eyes, with a choroidal thickness of 1.53 mm and 1.94 mm in the right and left eye (RE, LE), respectively. Peripapillary retinal nerve fiber evaluation showed thinning of the retinal nerve fiber layer in both eyes.

CONCLUSIONS

This report highlights multimodal imaging techniques for the critical assessment of patients with SWS, especially in rare cases with bilateral choroidal hemangioma of the choroid. Novel imaging modalities enable optimal management and follow-up of rare conditions, and our case adds further evidence to the existing literature.

Optical coherence tomography evidence of macular ganglion cell-inner plexiform layer thinning in eyes with subretinal drusenoid deposits

BACKGROUND/OBJECTIVES

The purpose of this study was to evaluate macular ganglion cell layer-inner plexiform layer (GCL-IPL) and choroidal thickness in early age-related macular degeneration (AMD) in eyes with subretinal drusenoid deposits (SDD).

SUBJECTS/METHODS

Comprehensive ophthalmological examination was performed. Near infrared reflectance and raster images using enhanced depth imaging were acquired with spectral domain optical coherence tomography. Drusen and SDD were diagnosed based on raster scans and near infrared reflectance. GCL-IPL maps were generated with automated segmentation and choroidal thickness maps were obtained by manually delineating the choroid-scleral boundary.

RESULTS

Forty-eight eyes from 48 patients (mean age 77.5 ± 5.7, range 68-90 years) with a diagnosis of early AMD and 42 eyes of 42 age-matched control subjects (mean age 76.9 ± 5.7, range 67-88 years) were included. Of these, 28 eyes (58.3%) had drusen alone, 4 eyes (8.3%) had SDD alone, and 16 eyes (33.3%) had drusen associated with SDD. Compared with controls, average choroidal thickness was significantly decreased in AMD eyes (P < 0.05). There was no significant difference in choroidal thickness in eyes with SDD with respect to those with drusen alone. GCL-IPL thickness was reduced in an annular pattern at the 3 and 6 mm macular areas in AMD patients with respect to controls (P < 0.05). GCL-IPL thickness at 3 mm was significantly reduced in eyes with SDD with respect to those with drusen alone (P = 0.03).

CONCLUSIONS

The GCL-IPL is reduced in thickness with an annular pattern in early AMD and is significantly thinner in eyes with SDD.

Pigment dispersion syndrome and pigmentary glaucoma: a review and update

INTRODUCTION

Pigment dispersion syndrome (PDS) is a condition where anomalous iridozonular contact leads to pigment dispersion throughout the anterior segment and the released pigment is abnormally deposited on various ocular structures.

CLINICAL PRESENTATION

The clinical presentation of PDS is defined by the presence of pigmented cells on the corneal endothelium, an increase of pigmentation of the trabecular meshwork, and mid-periphery transillumination defects of the iris. This syndrome, more common in myopes, is usually bilateral and can be associated with ocular hypertension or glaucoma. Secondary open-angle pigmentary glaucoma (PG) can develop due to reduction of the outflow of aqueous humour and consequent increase in intraocular pressure leading to glaucomatous optic neuropathy. Diagnosis of PG is commonly between 40 and 50 years of age, occurring more frequently in men. The advent of ultrasound biomicroscopy and anterior segment optical coherence tomography has contributed to enhancing our knowledge on the condition. Typical alterations of the anterior segment are the posterior insertion of the iris and iris concavity. Treatment of PG should be initiated early to hinder disease progression, glaucomatous damage, and vision loss. Management is based on medical therapy, laser iridotomy, selective laser trabeculoplasty, and filtration procedures.

CONCLUSIONS

The differential diagnosis of PDS with other disorders can be challenging and awareness of the condition together with meticulous ophthalmologic examination allows early diagnosis followed by appropriate management strategies. The present review is a comprehensive report on the clinical characteristics, pathogenesis, current management, and status quo of PDS and PG.

Ophthalmic manifestations in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a relatively common multisystemic inherited disease and has been extensively studied by multiple disciplines. Although genetic testing and confirmation are available, NF1 remains a clinical diagnosis. Many manifestations of NF1 involve the eye and orbit, and the ophthalmologist, therefore, plays a significant role in the diagnosis and treatment of NF1 patients. Improvements in diagnostic and imaging instruments have provided new insight to study the ophthalmic manifestations of the disease. We provide a comprehensive and up-to-date overview of the ocular and orbital manifestations of NF1.

Sturge-Weber Syndrome Associated with Monolateral Ocular Melanocytosis, Iris Mammillations, and Diffuse Choroidal Haemangioma

We present the case of a 12-year-old boy with Sturge-Weber syndrome and ocular melanocytosis who presented with bilateral naevus flammeus of the face and hyperpigmentation of the right iris associated with ipsilateral iris mammillations. The patient had glaucoma and a diffuse choroidal haemangioma of the right eye. Optical coherence tomography of the anterior segment confirmed iris hyper-pigmentation and did not show abnormalities of the chamber angle structures. B-scan ultrasonography and enhanced depth imaging optical coherence tomography were performed and showed a marked difference in thickness and reflectance between the right and left choroid. Visual field examinations with perimetry showed early defects in the right eye. Peripapillary optical coherence imaging showed borderline values of retinal nerve fibre layer thickness reduction in the right eye. Sturge-Weber syndrome associated with ocular melanocytosis and iris mammillations is an extremely rare condition. This paper highlights the role of multi-imaging methods in the enhanced evaluation of rare diseases towards choosing the most appropriate management strategies and improving the follow-up of patients over time.

Pathophysiology, diagnosis, and management of glaucoma associated with Sturge-Weber syndrome

PURPOSE

Sturge-Weber syndrome (SWS), also known as encephalotrigeminal angiomatosis, is a condition which includes leptomeningeal hemangioma, facial angiomatosis or nevus flammeus, and ocular changes. SWS can lead to severe complications of anterior segment involving conjunctiva and eyelids, whereas posterior segment of the eye may also be affected by diffuse choroidal hemorrhages. This article was written with the objectives to determine the pathophysiology, diagnosis, and treatment of glaucoma associated with this rare and challenging disorder.

METHODS

A detailed literature search was conducted on PubMed, EMBASE, Cochrane Library, and Google Scholar using the key words. Forty-five articles matched our inclusion criteria that were included in this systematic review.

RESULTS

Glaucoma is the one of the commonest ocular manifestations of SWS. It is caused by anterior chamber malformations, increased pressure in the episcleral veins, and changes in ocular hemodynamics. Glaucoma associated with SWS is usually congenital but can develop adults as well. The treatment of glaucoma associated with SWS is quite challenging because of early-onset, severe visual field impairment at the time of diagnosis, and unresponsiveness to standard medical treatment. Several surgical procedures have been devised but the long-term control of the intraocular pressure and visual function remain unsatisfactory. Modifications in the filtration surgery techniques and use of newer anti-fibrotic agents have produced good control of intraocular pressure.

CONCLUSION

Management of glaucoma associated with SWS is multi-dimensional and needs both medical and surgical interventions for better control. The treatment should be devised on case to case basis depending upon the intraocular pressure, stage of the disease, and type of glaucoma.

A review of the role of ultrasound biomicroscopy in glaucoma associated with rare diseases of the anterior segment

Ultrasound biomicroscopy is a non-invasive imaging technique, which allows high-resolution evaluation of the anatomical features of the anterior segment of the eye regardless of optical media transparency. This technique provides diagnostically significant information in vivo for the cornea, anterior chamber, chamber angle, iris, posterior chamber, zonules, ciliary body, and lens, and is of great value in assessment of the mechanisms of glaucoma onset. The purpose of this paper is to review the use of ultrasound biomicroscopy in the diagnosis and management of rare diseases of the anterior segment such as mesodermal dysgenesis of the neural crest, iridocorneal endothelial syndrome, phakomatoses, and metabolic disorders.

An Update on the Ophthalmologic Features in the Phakomatoses

Neurofibromatosis type 1, tuberous sclerosis complex, and Von Hippel-Lindau disease, historically classified as the phakomatoses, are hereditary multisystem disorders characterized by the presence of hamartoma, which carry the risk of malignant transformation. The alteration of tumor suppressor genes seems to be at the basis of their pathophysiogenetic mechanism. Lisch and choroidal nodules in neurofibromatosis type 1, retinal astrocytomas in tuberous sclerosis complex, and retinal capillary hemangioma in Von Hippel-Lindau disease are the principal ophthalmic hamartomatous manifestations. The advent of novel imaging techniques such as near infrared reflectance and optical coherence tomography has provided unprecedented insight on the choroidal and retinal features of these diseases. These methods have improved early diagnosis and the ongoing surveillance in these conditions. Among an array of treatment modalities, antivascular endothelial growth factor therapy has been used in the management of retinal hamartomas but results have been varied. This review is an update on the pathophysiogenetic mechanisms, ophthalmic manifestations, and novel treatment strategies in the phakomatoses with emphasis on the role of imaging techniques.

Neurofibromatosis: an update of ophthalmic characteristics and applications of optical coherence tomography

Neurofibromatosis (NF) is a multisystem disorder and tumor predisposition syndrome caused by genetic mutation on chromosome 17-17q11.2 in NF type 1 (NF1), and on chromosome 22-22q12.2 in NF type 2. The disorder is characterized by considerable heterogeneity of clinical expression. NF1 is the form with the most characteristic ocular manifestations. Lisch nodules of the iris are among the well-known diagnostic criteria for the disease. Glaucoma and associated globe enlargement have been described in a significant proportion of patients with NF1 and orbital–facial involvement. Optic nerve glioma may cause strabismus and proptosis, and palpebral neurofibroma may reach considerable size and occasionally show malignant transformation. Near infrared reflectance has greatly contributed to enhancing our knowledge on choroidal alterations in NF1. Indeed, some authors have proposed to include these among the diagnostic criteria. Optical coherence tomography has given new insight on retinal alterations and is a noninvasive tool in the management of optic nerve gliomas in children. Ocular manifestations in NF type 2 can range from early-onset cataracts in up to 80% of cases to optic nerve hamartomas and combined pigment epithelial and retinal hamartomas.

Ocular manifestations of Sturge-Weber syndrome: pathogenesis, diagnosis, and management

Sturge–Weber syndrome has been included in the group of phakomatoses that is characterized by hamartomas involving the brain, skin, and eyes. The characteristic facial port-wine stain, involving the first branch of the trigeminal nerve and the embryonic vasculature distribution in this area, leads to several ocular complications of the anterior segment and can involve the eyelids and conjunctiva. The posterior segment of the eyes is also affected with diffuse choroidal hemangiomas. However, the most frequent ocular comorbidity is glaucoma with a prevalence rate ranging from 30%–70%. Glaucoma is related to anterior chamber malformations, high episcleral venous pressure (EVP), and changes in ocular hemodynamics. Glaucoma can be diagnosed at birth, but the disease can also develop during childhood and in adults. The management of glaucoma in Sturge–Weber syndrome patients is particularly challenging because of early onset, frequently associated severe visual field impairment at the time of diagnosis, and unresponsiveness to standard treatment. Several surgical approaches have been proposed, but long-term prognosis for both intraocular pressure control and visual function remains unsatisfactory in these patients. Choroidal hemangiomas may also lead to visual impairment thorough exudative retinal detachment and macular edema. Treatment of exudative hemangioma complications is aimed at destructing the tumor or decreasing tumor leakage.