The cupped disc. Who needs neuroimaging?

Normal-Tension Glaucoma Complicated by a Giant Internal Carotid-Ophthalmic Artery Aneurysm

Purpose. We describe a patient with normal tension glaucoma (NTG) of several years whose management was complicated by the presence of a giant internal carotid-ophthalmic artery aneurysm. Observations. A 72-year-old woman presented to our glaucoma clinic with accelerated deterioration of her vision in her left eye (OS) over a 1-month period. Her ophthalmic history was most notable for bilateral NTG diagnosed 3 years prior which had been treated with several laser trabeculoplasty OS and topical bimatoprost 0.01% eye drops in both eyes (OU). Upon evaluation, her visual acuity OS had worsened, and visual field (VF) testing showed extensive progressive losses temporally and pericentrally OS over a year with stable IOP measurements and no neurological complaints. Given her atypical NTG progression, she was referred for an urgent neurological evaluation which revealed an unruptured giant left internal carotid-ophthalmic aneurysm. Following the successful treatment of the aneurysm with platinum coils, she continued to demonstrate additional bilateral ophthalmic changes including further progression of VF loss and RNFL thinning OS > OD on follow-up. Conclusion and Importance. Overall, this report describes a unique complication in the management of a patient with chronic bilateral NTG in the form of a giant internal carotid-ophthalmic aneurysm. Moreover, it highlights the need for clinicians to maintain a degree of suspicion for compressive lesions of the optic nerve when presented with atypical progression of VFs and/or visual acuity loss in glaucomatous patients.

Pituitary Macroadenoma with Optic Cupping Masquerading as Normal Tension Glaucoma

When non-glaucomatous disease with disc cupping mimics normal-tension glaucoma (NTG), diagnosis is challenging. The typical optic disc features of glaucomatous disease are often subjective, and often overlap with disc changes in compressive intracranial lesions. Ancillary diagnostic testing such as retinal nerve fiber layer (RNFL) analysis and visual field testing can elevate the index of suspicion of an underlying non-glaucomatous process. We present a case of a nonfunctional macroadenoma coexisting with NTG, although it is unclear if the concurrent brain lesion aggravated or caused it. This case highlights the diagnostic challenge of recognizing optic cupping and non-matching abnormalities in the visual field from a coexisting intracranial lesion, even in the absence of other neurological signs.

Discriminating Between Compressive Optic Neuropathy With Glaucoma-Like Cupping and Glaucomatous Optic Neuropathy Using OCT and OCTA

Purpose

To discriminate between compressive optic neuropathy with glaucoma-like cupping (GL-CON) and glaucomatous optic neuropathy (GON) by comparing the peripapillary retinal nerve fiber layer (pRNFL) thickness and retinal microvasculature using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA).

Methods

In this retrospective cross-sectional study, OCT scans were performed on 28 eyes of GL-CON, 34 eyes of GON, and 41control eyes to determine the pRNFL thickness, ganglion cell complex thickness, and cup/disc ratio. OCTA scans were conducted for 12 eyes of GL-CON, 15 eyes of GON, and 15 control eyes to measure the vessel density of the peripapillary and macular areas. Analysis of covariance was used to perform the comparisons, and the area under the curve was calculated.

Results

The GON eyes had a significantly thinner pRNFL in the inferior quadrant and greater vertical cup/disc ratio than the GL-CON eyes. In the radial peripapillary capillary segment, the vessel density of the GON in the inferior sectors was significantly lower than in the GL-CON. The superficial macular vessel density in the whole-image, peritemporal, perinasal, and peri-inferior sectors was significantly smaller in the GON group than in the GL-CON group. The best parameter for discriminating between GL-CON and GON was the superficial macular vessel density in the peritemporal sector.

Conclusions

GL-CON eyes showed a characteristic pattern of pRNFL and retinal microvascular changes.

Translational Relevance

GL-CON can be effectively distinguished from GON by detecting the alterations in the pRNFL and retinal microvasculature using OCT and OCTA.

Clinical outcomes in children and adolescents referred for increased cup:disk ratio at a tertiary referral center

PURPOSE

To report clinical outcomes and risk factors for glaucoma in children and adolescents referred for increased cup:disk ratios (CDRs) to a tertiary referral center.

METHODS

This retrospective, single-center study examined all pediatric patients evaluated for increased CDR at Wills Eye Hospital. Patients who had previous known ocular disease were excluded. Demographic data, including sex, age, and race/ethnicity were recorded, as were baseline and follow-up ophthalmic examination findings, including intraocular pressure (IOP), CDR, diurnal curve, gonioscopy findings, and refractive error. Risks of glaucoma diagnosis based on these data were analyzed.

RESULTS

A total of 167 patients were included, of whom 6 were found to have glaucoma. Despite more than 2 years' follow-up on 61 patients, all glaucoma patients were identified within the first 3 months of evaluation. Baseline IOP was statistically significantly higher in glaucomatous patients than nonglaucomatous patients (28 ± 7 vs 15 ± 4, resp. [P = 0.0002]), as was maximum IOP on diurnal curve (24 ± 3 vs 17 ± 3 [P = 0.0005]).

CONCLUSIONS

In our study cohort, diagnosis of glaucoma was apparent in the first year of evaluation. Baseline IOP and maximal IOP on diurnal curve were found to be statistically significantly associated with glaucoma diagnosis in pediatric patients referred for increased CDR.

Artificial Intelligence Meets Neuro-Ophthalmology

ABSTRACT

Recent advances in artificial intelligence have provided ophthalmologists with fast, accurate, and automated means for diagnosing and treating ocular conditions, paving the way to a modern and scalable eye care system. Compared to other ophthalmic disciplines, neuro-ophthalmology has, until recently, not benefitted from significant advances in the area of artificial intelligence. In this narrative review, we summarize and discuss recent advancements utilizing artificial intelligence for the detection of structural and functional optic nerve head abnormalities, and ocular movement disorders in neuro-ophthalmology.

Glaucomatous Type Cupping Caused by Internal Carotid Artery Compression: a Case Report

A 71-year-old woman with a diagnosis of normal tension glaucoma (NTG) presented with complains of progressive visual loss in the right eye. Examination revealed features consistent with compressive optic neuropathy. Although brain magnetic resonance imaging (MRI) was initially interpreted as normal, re-evaluation disclosed a compression on the right optic nerve from the right internal carotid artery. We highlight the clinical differential diagnosis between NTG and compressive optic neuropathy. This case is a reminder that a compressive optic neuropathy may be caused by anatomical variation of normal intracranial structures.

Yield of investigations in patients with questionable nonglaucomatous optic neuropathy

OBJECTIVE

Nonglaucomatous optic neuropathy (NGON) may often be mistaken for normal-tension glaucoma. The distinction between these two entities is important in determining treatment, prognosis, and need for further investigations. We report characteristics of a cohort of patients referred for neuro-ophthalmologic consultation to distinguish between glaucomatous (GON) and NGON.

METHODS

Retrospective chart review of patients presenting to a tertiary neuro-ophthalmology practice investigated for GON versus NGON between 2018 and 2020. Patients were classified as GON or NGON based on presence of optic disc pallor, degree of cupping, central visual acuity, and/or when investigations yielded a cause of NGON.

RESULTS

Eighty-three patients were enrolled. Seventy-one patients (86%) were deemed to have possible NGON after initial evaluation and having undergone neuroimaging. Of these, 14 patients (19.7%) were determined to have NGON and 7 patients (9.9%) both GON and NGON. The most common causes of NGON were undetermined (8), previous optic neuritis (4), and neurovascular conflict (2). The yield of neuroimaging was low, with abnormalities seen in only 4 of 71 patients (5.6%). No patients with bilateral cupping and no relative afferent pupillary defect (RAPD) had abnormalities on imaging, and no patients with positive imaging required intervention. Patients with NGON had lower intraocular pressure and cup-to-disc ratio and usually had optic disc pallor (86%). Nerve fibre bundle defects were most common in both GON and NGON, with more nasal defects seen in GON.

CONCLUSIONS

When NGON resembles GON, the underlying cause is often undetermined, and the yield of neuroimaging is low. The yield of investigating patients with bilateral cupping and no RAPD for NGON is especially low.

Neuro-Ophthalmological Optic Nerve Cupping: An Overview

Optic nerve cupping or enlargement of the cup-to-disc ratio is widely recognized as a feature of glaucoma, however it may also occur in non-glaucomatous optic neuropathies. The most well-recognized non-glaucomatous optic neuropathies that cause cupping include compressive optic neuropathies, arteritic anterior ischemic optic neuropathies, hereditary optic neuropathies, and optic neuritis. Cupping is thought to consist of two main components: prelaminar and laminar thinning. The former is a shallow form of cupping and related to loss of retinal ganglion cells, whereas the latter involves damage to the lamina cribrosa and peripapillary scleral connective tissue. Differentiating glaucomatous and non-glaucomatous optic nerve cupping remains challenging even for experienced observers. Classically, the optic nerve in non-glaucomatous causes has pallor of the neuroretinal rim, but the optic nerve should not be examined in isolation. The patient’s medical history, history of presenting illness, visual function (visual acuity, color vision and visual field testing) and ocular examination also need to be considered. Ancillary testing such as optical coherence tomography of the retinal nerve fiber layer and ganglion cell layer-inner plexiform layer may also be helpful in localizing the disease. In this review, we review the non-glaucomatous causes of cupping and provide an approach to evaluating a patient that presents with an enlarged cup-to-disc ratio.

Revisiting the Awareness and Understanding the Associations between Intracranial Tumors and Optic Neuropathy

The aim of this paper is to report clinically various cases of intracranial tumors in patients referred to glaucoma clinic for consultation. The secondary aim was to increase the awareness of intracranial tumors in atypical cases of glaucoma. We present the retrospective analysis of five patients referred to glaucoma clinic for consultation. Due to atypical course of the disease, in addition to standard glaucoma examinations, all patients had a neurologic full visual field, color vision, and MRI done. In all patients, intracranial malignancies were found, some patients underwent surgery of the lesions with consecutive clinical improvements. Interestingly, in some patients, coexisting glaucoma was diagnosed. Patients were selected deliberately to present a wide spectrum of possible clinical scenarios when glaucoma may be complicated by intracranial tumors. Sometimes, the relevance of intracranial tumors with respect to their influence on the clinical picture of the optic nerve cannot be established. To conclude, in the “atypical cases of glaucoma” the assessment of the optic nerve may indicate the necessity of neuroimaging in differential diagnostics.

Optic Disc Cupping Due to Dolichoectatic Internal Carotid Artery Optic Nerve Compression

BACKGROUND

To determine whether significant compression of the optic nerve by the internal carotid artery (ICA) can produce an optic neuropathy with optic disc cupping that resembles glaucoma in patients without elevated intraocular pressure (IOP).

METHODS

This was a retrospective case series of patients referred to neuro-ophthalmology for a possible nonglaucomatous optic neuropathy. Patients were included in the study if they had preserved visual acuity, optic disc-related visual field defects, optic nerve cupping, IOP less than 21 mm Hg, open angles, and unequivocal radiological compression of the ipsilateral optic nerve by an intracranial blood vessel.

RESULTS

Three patients were included with a mean age of 56.3 (range 29-82) years. Patient 1 was a 58-year-old man incidentally noted to have left optic nerve cupping on a routine examination. He had an inferior arcuate defect and the left prechiasmatic optic nerve was elevated and compressed by a tortuous left ICA. Patient 2 was a 29-year-old man with a normal-tension glaucoma (NTG) diagnosis for 7 years in the right eye treated with latanoprost. He had a superior greater than inferior arcuate defect and there was vascular compression of the optic nerve between the supraclinoid ICA and A1 segment of the anterior cerebral artery. Patient 3 was an 82-year-old woman with an NTG diagnosis for 10 years who had progression of her visual field defects despite low IOPs. MRI showed mass effect on the right optic nerve by a dolichoectatic right supraclinoid ICA.

CONCLUSIONS

Significant compression of the optic nerve by a normal, tortuous, or dolichoectatic ICA may result in an optic neuropathy with optic disc cupping that resembles glaucoma.

Rapid visual field progression in a patient with glaucoma as the presenting manifestation of sarcoidosis

PURPOSE

To report a case of accelerated visual field progression secondary to a new orbital apex lesion in a patient with a longstanding history of fatigue and cough.

OBSERVATIONS

A 73-year-old myopic female with known open angle glaucoma presented with accelerated unilateral visual field progression. Maximally tolerated medical therapy was instituted over a period of 1-2 years with imminent discussions of surgical intervention. Around this time the patient reported worsening cough and fatigue, which were initially attributed to glaucoma medication side effects. Consideration of the patient's remote history of melanoma and the current asymmetry of the visual field progression triggered a computerized tomography (CT) scan of the orbits as part of the management. An orbital apex lesion was discovered, raising suspicion for metastatic melanoma, and restaging CT imaging uncovered renal, hepatic, and mediastinal masses. Unexpectedly, biopsies revealed non-necrotizing granulomatous inflammatory processes consistent with a diagnosis of sarcoidosis. It is perhaps noteworthy that the patient had received interferon therapy for management of her melanoma; previous reports have associated interferon exposure with subsequent sarcoid disease, regardless of duration of therapy or elapsed time since exposure.

CONCLUSIONS AND IMPORTANCE

Although rare, sarcoidosis can occur virtually anywhere in the body, including the orbital apex. Its common early symptoms, fatigue and cough, are insidious and seen frequently in this patient's age group and medication side effect profile. It is important to maintain an appropriate index of suspicion when monitoring atypical visual field progression in a patient with glaucoma. In this case, imaging, subsequent biopsy, and a multi-specialty team were integral to this patient's diagnosis and management.

The American Glaucoma Society 100: Articles with Significant Impact on Clinical Glaucoma Care

PURPOSE

To identify 100 articles with significant impact on the clinical care of patients with glaucoma.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 108 members of the American Glaucoma Society (AGS) in the original survey and 63 in the follow-up survey.

METHODS

The 100 most frequently cited English-language original articles relevant to glaucoma were identified via a Scopus search. The American Academy of Ophthalmology (AAO) Preferred Practice Pattern Glaucoma Panel selected an additional 100 articles including newer and "classic" papers. An anonymous survey including the list of 200 articles was distributed to the AGS membership. Survey participants were asked to rate the impact of each article on the clinical care of glaucoma patients using a 4-point Likert scale. Survey respondents were able to provide "write-in" suggestions for the AGS 100. A subsequent anonymous follow-up survey was distributed asking participants to use the same Likert scale to rate 31 "write-in" articles suggested in the original survey. The AGS 100 was created by ranking the top 100 articles based on mean Likert scores from the original and follow-up surveys.

MAIN OUTCOME MEASURES

Original English-language articles that have influenced the clinical care of patients with glaucoma.

RESULTS

The mean ± standard deviation Likert score of articles included in the AGS 100 was 2.9 ± 0.3 (range, 2.47-3.69). The median citation number was 345 (range, 11-2426). Publication year ranged from 1965 to 2020. Articles were published in 14 journals, the most common of which were Ophthalmology (42%), American Journal of Ophthalmology (21%), and Archives of Ophthalmology (20%). Forty-eight articles were derived from randomized clinical trials.

CONCLUSIONS

The AGS 100 is a collection of articles judged to have significant clinical impact on glaucoma care. The list will serve as an online educational resource for ophthalmologists in training and in practice.

Incidence of non-glaucomatous ocular disease in patients with asymmetric optic disc cupping

PURPOSE

To evaluate the incidence of non-glaucomatous ocular disease in patients with asymmetric optic disc cupping.

METHODS

A retrospective case series, including consecutive patients with cup-to-disc ratio (CDR) asymmetry greater than 0.2. All patients underwent a complete neuro-ophthalmological examination, automated perimetry with the Humphrey 24-2 visual fields program. Retinal nerve fibre layer thickness was measured by optical coherence tomography (OCT). The results of neuroimaging, macular OCT and blood tests were recorded as well. Patients were assigned a diagnosis of glaucomatous optic neuropathy (GON) or non-glaucomatous disease (NGD). The main outcome measure was the rate of non-glaucomatous ocular disease.

RESULTS

A total of 120 (67 males) patients with a mean age of 71.1 ± 12.5 years met the inclusion criteria and were included in this study. The mean asymmetry in CDR between the eyes was 0.3 ± 0.13 (range, 0.2-0.9). Twenty patients (16.6%) had a visual field defect not typical for glaucoma and positive relative afferent pupillary defect was found in 24 patients (20%). Six patients were found to have newly diagnosed non-glaucomatous ocular disease: maculopathy in three patients, retinopathy in one patient and traumatic optic neuropathy in two patients. Patients with NGD were significantly younger than the patients with GON (59.8 ± 23.3 vs. 71.3 ± 11.5 years, P = 0.001). Optic disc pallor was found in 4/93 patients with glaucoma compared to 3/6 with newly diagnosed non-glaucomatous disease (4.7% vs. 50.0%, P = 0.03).

CONCLUSIONS

Asymmetric optic disc cupping can be associated with non-glaucomatous disease and may warrant neuro-ophthalmological evaluation, especially in younger patients or those with optic disc pallor.

Glaucoma Mimickers: A major review of causes, diagnostic evaluation, and recommendations

Background: Glaucoma is characterized by chronic progressive optic neuropathy with corresponding visual field changes, with or without raised intraocular pressure (IOP). When diagnosing glaucoma or monitoring its progression, the examiner has to rely on the appearance of the optic disc, characteristic retinal nerve fiber layer defects, and corresponding visual field defects. However, similar changes and symptoms may be observed in several other disorders of the optic nerve and retina that may mimic glaucoma, often leading to misdiagnosis. Methods and result: The consequences of misdiagnosis not only result in improper treatment that may impact vision but also would negatively affect the overall health, psychological well-being of the patient, and may have considerable economic implications.Conclusion: The current review describes various conditions that mimic glaucoma and the features that help differentiate these conditions from glaucoma.

Double trouble with the disc - Hickam's dictum versus Occam's razor!

Differentiating glaucomatous and non-glaucomatous optic neuropathy can be challenging even to an experienced clinician and it is even more complex to identify early ophthalmic manifestation of neurological lesions when the optic nerve is already jeopardized by advanced glaucoma. This is a case of a patient with juvenile open-angle glaucoma with advanced glaucomatous cupping who developed an intracranial tuberculoma and subsequent obstructive hydrocephalus. Subtle edema identified in an almost totally damaged nerve, coupled with a history of headache and tinnitus, was the clinching factor prompting early treatment in the form of ventriculoperitoneal shunting and antituberculous therapy. Detailed history, systematic clinical exam, and appropriate imaging are imperative in reducing morbidity and sometimes mortality associated with these neurological conditions.

Results of Neuroimaging in Patients with Atypical Normal-Tension Glaucoma

Aim

The aim of the study was to determine the frequency of pathologies which can mimic normal-tension glaucoma (NTG), observed in neuroimaging of NTG patients, and to evaluate the frequency of pathologies in determined additional indications for neuroimaging. Material and Methods. The studied group consisted of 126 NTG patients who met at least one of the following criteria: unilateral NTG, damage in the visual field (VF) inconsistent with optic disc appearance, fast VF progression, worsening of visual acuity, predominant optic disc pallor rather than optic disc excavation, diagnosis under the age of 50, and scotoma in VF restricted by a vertical line. The patients included in the research underwent MRI scans of the brain and both orbits.

Results

After neuroimaging, the results of 29 (23%) patients were qualified as positive; 18 (14.2%) of the identified pathologies were found to clinically affect the visual pathway. The most frequent brain pathology was intracranial meningiomas, observed in 4 patients (3.1%), followed by optic nerve sheath meningiomas diagnosed in 3 cases (2.4%), and brain glioma in 1 patient (0.8%). Pituitary gland adenomas were described in 6 patients (4.5%); 3 of the tumours were in contact with the optic chiasm. 53 (40%) patients had minimal ischemic changes in different regions of the brain. In the case of worsening BCVA or fast VF progression, the frequency of positive results was the highest (50% and 40%), whereas in the case of diagnosis at a young age and unilateral involvement, neuropathology was the rarest (0% and 6.9%).

Conclusions

In the case of NTG, the decision to perform neuroimaging should be made after a detailed assessment of clinical status, rather in the event of finding the signs of possible compressive optic neuropathy than as an obligatory procedure for every patient.

Normal tension glaucoma in Asia: Epidemiology, pathogenesis, diagnosis, and management

Normal tension glaucoma (NTG) has similar optic neuropathy as primary open-angle glaucoma (POAG), but intraocular pressure (IOP) is within the normal range. Compared with high-pressure POAG, the development of NTG is possibly a consequence of a complex interaction of several ocular and systemic factors. Recent data have shown higher translaminar pressure gradient due to impaired cerebrospinal fluid dynamics may account for the pathogenic mechanism. Insufficient blood supply and vascular dysregulation may also be the cause of the disease. In clinical evaluation, NTG is a diagnosis by excluding other nonglaucomatous optic neuropathies. NTG is characterized by larger and deeper optic-disc cupping, more central visual field defects and a higher incidence of disc hemorrhage compared with POAG. In clinical practice, controlling IOP as low as possible (with medication, laser trabeculoplasty, or surgery) is the key to manage NTG patients. In addition to IOP reduction, the control of systemic risk factors or improving ocular perfusion may be beneficial therapies. NTG is more prevalent in Asia than in the Western countries. Due to increasing old population and underdiagnoses in the clinical settings, NTG became a great challenge for ophthalmologist in Asia. Therefore, the aim of this article is to focus on the epidemiology, to update pathogenesis, diagnosis, and management for NTG.

Suprasellar meningioma presenting with glaucomatous type cupping

PURPOSE

To describe a case of a suprasellar meningioma compressing the chiasm from below and producing a unilateral fascicular (nasal) visual field defect that mimicked glaucomatous cupping.

CASE REPORT

A 78-year-old man presented with painless, progressive, unilateral arcuate visual field defect. He was diagnosed with "normal tension glaucoma" based on an asymmetric cup to disc ratio. Despite treatment with anti-glaucoma drops, the visual field defect progressed. Neurophthalmic evaluation was consistent with a compressive optic neuropathy OD. Brain MRI showed a suprasellar meningioma compressing on the junction of the optic nerve and chiasm from below.

CONCLUSION

Although junctional visual field loss (e.g. junctional scotoma and junctional scotoma of Traquair) are well-known presentations of compressive lesions at the optic chiasm, we describe a monocular, ipsilateral compressive superior nasal defect and asymmetric cupping as the presenting sign of a junctional compressive lesion mimicking glaucomatous cupping.

Neuro-ophthalmic Disease in Pediatric Glaucoma Practice

PRECIS

Pediatric glaucoma referral to neuro-ophthalmology has a high yield for diagnosing neurological disease and neuroimaging in this cohort often uncovers intracranial abnormalities.

PURPOSE

Multiple studies have examined the utility of neuro-ophthalmology referrals in an adult glaucoma patient population. No similar studies in the pediatric glaucoma population have been completed. An analysis of pediatric referral patterns and clinical characteristics can serve to guide future physician referrals and improve patient outcomes.

MATERIALS AND METHODS

A retrospective review of medical records was conducted to identify pediatric patients evaluated by both glaucoma and neuro-ophthalmology services at Bascom Palmer Eye Institute from January 2013 to August 2018. Records were reviewed for clinical examination findings, demographics, ophthalmic imaging, neuroimaging, and ultimate diagnosis.

RESULTS

A total of 59 patients, average age 10 years old, were included for analysis. The majority of patients were referred from pediatric glaucoma to neuro-ophthalmology (n=52, 88.1%). The most common reasons for referral included suspected nonglaucomatous optic neuropathy (n=14), optic disc swelling (n=7), color vision deficiency (n=6), and nonglaucomatous visual field defect (n=4). Referral to neuro-ophthalmology resulted in neuro-imaging in 22 patients (22/52, 42.3%), with 7 patients (7/52, 13.7%) having pathology on the scan. Ultimately, 38 patients (73.1%) referred to neuro-ophthalmology had an ultimate diagnosis unrelated to glaucoma. Color vision abnormality, optic nerve pallor, and/or retinal nerve fiber layer <70 µm in at least 1 eye were associated with a diagnosis unrelated to glaucoma. Of the 7 patients referred from neuro-ophthalmology to pediatric glaucoma, none were diagnosed with glaucoma or started on intraocular pressure lowering therapy.

CONCLUSIONS

Patients referred from pediatric glaucoma to neuro-ophthalmology often have nonglaucomatous disease requiring subspecialty evaluation and neuroimaging. Neuroimaging in this cohort is high yield for uncovering intracranial pathology.

Latest Developments in Normal-Pressure Glaucoma: Diagnosis, Epidemiology, Genetics, Etiology, Causes and Mechanisms to Management

Normal-pressure glaucoma (NPG) is part of the spectrum of the open-angle glaucomas and morphologically characterized, as any glaucoma, by a loss of neuroretinal rim parallel to an enlargement and deepening of the optic cup, and development or enlargement of parapapillary beta zone. These morphological characteristics, in addition to the therapeutic benefit of lowering the intraocular pressure (IOP), make NPG differ from vascular-induced optic neuropathy. Based on the anatomy of the optic nerve as a cerebral fascicle, the physiological counter-pressure against the IOP is the orbital cerebrospinal fluid pressure (CSFP), with both pressures forming the trans-lamina cribrosa pressure difference (TLCPD). In contrast to the IOP, the TLCPD is the true pressure exerting force on the optic nerve fibers when passing through the lamina cribrosa. As a theoretical notion, an abnormally high TLCPD due to a low CSFP, in association with a low arterial blood pressure, could therefore be involved in the pathogenesis of NPG. It fits with the finding that the reduction of the IOP (and thus indirectly of the TLCPD) is (the only proven) procedure for NPG therapy. This review additionally highlights the genetic background, diagnostic methods, and therapeutic modalities of NPG.

Optic nerve head cupping in glaucomatous and non-glaucomatous optic neuropathy

BACKGROUND

Enlargement of optic disc cupping is seen both in glaucoma and in neurological disorders. We used enhanced depth imaging with spectral-domain optical coherence tomography to differentiate glaucoma from non-glaucomatous optic neuropathy.

METHODS

The optic discs were scanned in this prospective comparative study, and the lamina cribrosa (LC) thickness and anterior laminar depth (ALD) in the central, superior and inferior optic nerve head, and peripapillary choroidal thicknesses, were measured.

RESULTS

There were 31 eyes of 31 patients with severe glaucoma and 33 eyes of 19 patients with non-glaucomatous cupping. Eyes of 29 healthy controls were also enrolled. There was no significant difference in the cup-to-disc ratio and in the average peripapillary nerve fibre layer thickness between the glaucoma and non-glaucomatous cupping groups (p>0.99). The average peripapillary choroidal thickness was thinner in glaucoma eyes than in the control eyes after adjusting for age and axial length. Glaucomatous and non-glaucomatous eyes had greater ALD and thinner LC than the control eyes (p<0.001 for both). ALDs of glaucoma eyes were deeper than non-glaucomatous eyes (p=0.01 for central ALD) when age, axial length and peripapillary choroidal thickness were included in the linear mixed model. Prelaminar thickness and LC thickness of glaucoma eyes were not different from non-glaucomatous eyes after adjusting.

CONCLUSION

Deeper ALD was observed in glaucoma than non-glaucomatous cupping after adjusting for choroidal thickness.

Chiasmal syndrome: Clinical characteristics in patients attending an ophthalmological center

Purpose

To present the clinical characteristics of a group of patients with the diagnosis of chiasmal syndrome who attended a large ophthalmological institute.

Methods

Retrospective, observational clinical study with the review of medical records of patients with a diagnosis of chiasmal syndrome. The following variables were assessed: demographic characteristics, chief complaint upon presentation, best-corrected visual acuity (BCVA), presence or absence of diplopia, pupillary responses, optic nerve head morphology, etiology, and results from the ancillary tests including Ishihara test, Goldmann visual field (GVF) perimetry and neuroimaging.

Results

A total of 104 met the inclusion criteria, with a median age of 52 years (range 4-86 years). Fifty-four patients (51.9%) were referred to our institution with a diagnosis of a causative etiology for chiasmal syndrome, while in 50 (48.1%) the diagnosis was performed at our center. The most common presenting symptom was low visual acuity in 57 patients (54.8%), and the most common GVF defect was bitemporal hemianopsia in 39 patients (78 eyes, 39.8%). Pupillary abnormalities were present in 58 patients (55.7%), the optic nerve revealed pallor at any degree in 67 patients (64.4%) and the Ishihara test was affected in 65 patients (62.5%). The most common diagnosis was pituitary macroadenoma.

Conclusion

The ophthalmologist participates in the diagnosis and rehabilitation of patients with chiasmal syndrome. Low visual acuity is the most common symptom at presentation, and bitemporal hemianopia the most frequent GVF defect. Examination of the optic nerve head and pupillary responses, and ancillary tests including Ishihara test and neuroimaging are relevant for diagnosis.

Neurophthalmological conditions mimicking glaucomatous optic neuropathy: analysis of the most common causes of misdiagnosis

BACKGROUND

To analyze the most common neurophthalmological conditions that may mimic glaucomatous optic neuropathy and to determine which most often lead to misdiagnosis when evaluated by a glaucoma specialist.

METHODS

We reviewed the charts of consecutive patients with optic neuropathies caused by neurophthalmological conditions screened in a single Eye Clinic within a period of 24 months. Within these enrolled patients, we selected the eyes whose fundoscopic appearance could resemble glaucoma based in pre-defined criteria (vertical cup-to-disc ratio ≥0.6, asymmetry of the cup-to-disc ratio ≥0.2 between eyes, presence of localized retinal nerve fiber layer and/or neuroretinal rim defects, and disc haemorrhages). Then, color fundus photographs and Humphrey Visual Field tests (HVF) of these eyes were mixed with tests from 21 consecutive glaucomatous patients (42 eyes with normal tension glaucoma). These images were mixed randomly and a masked glaucoma specialist was asked to distinguish if each set of exams was from a patient with glaucoma or with a neurophthalmologic condition.

RESULTS

Among the 101 eyes (68 patients) enrolled with neurophthalmological diseases, 16 (15.8%) were classified as conditions that could mimic glaucoma. The most common diagnoses were ischemic optic neuropathy (25%), compressive optic neuropathy (18.7%) and hereditary optic neuropathy (18.7%). Based on the analysis of fundus photographs and HVF tests, 25% of these were misdiagnosed as glaucoma (two ischemic optic neuropathies and two congenital optic disc anomalies). Conversely, 11.9% of the glaucomatous neuropathies were misdiagnosed as neurophthalmological disorders. Overall, the glaucoma specialist correctly diagnosed 84.5% of the eyes.

CONCLUSIONS

Some neurophthalmological disorders can mimic glaucoma. In our study, isquemic and compressive optic neuropathies were the ones that most often did so. Almost one quarter of the eyes were misdiagnosed when evaluated by a glaucoma specialist, which can lead to inadequate management and influence the prognosis of these patients.

Macular Ganglion Cell Analysis Determined by Cirrus HD Optical Coherence Tomography for Early Detecting Chiasmal Compression

Purpose

To evaluate the performance of macular ganglion cell-inner plexiform layer (mGCIPL) measurement with Cirrus high-definition (HD) optical coherence tomography (OCT) for early detection of optic chiasmal compression.

Methods

Forty-six eyes of 46 patients with optic chiasmal compression caused by a pituitary adenoma (PA group), 31 eyes of 31 patients with normal tension glaucoma (NTG group), and 32 eyes of 32 normal participants (control group) were enrolled. The PA group was subdivided into two subgroups, which comprised patients with temporal visual field (VF) defects (perimetric PA group, 34 eyes) and without VF defect (preperimetric PA group, 12 eyes). The mGCIPL thickness and circumpapillary retinal nerve fiber layer (cpRNFL) thickness were measured using Cirrus HD-OCT. We calculated the number of patients who had an abnormal GCA sector map, defined as at least one yellow or red sector.

Results

Eyes in the perimetric PA group had significantly decreased mGCIPL thickness in all sectors. Eyes in the preperimetric PA group had significantly thinner mGCIPL in the superior, superonasal, inferonasal, and inferior sectors than eyes in control group, but no changes in cpRNFL parameters were observed. The mGCIPL thickness in inferonasal area showed the greatest AUC value (0.965), followed by the superonasal area (0.958) for discriminating preperimetric PA group from the control group. A higher reduction rate of mGCIPL thickness was noted in the nasal sector compared to other sectors, which was irrespective of temporal visual field defects. The mGCIPL thickness maps showed superonasal (P = 0.003) and inferonasal thinning in the PA group (P = 0.003), while inferotemporal thinning was revealed in the NTG group (P = 0.001).

Conclusions

Macular GCIPL thickness parameters obtained with the Cirrus HD-OCT were useful in early detection of chiasmal compression and differentiating from NTG by characteristic nasal mGCIPL thinning.

Ophthalmic segment of internal carotid artery aneurysm mimicking normal tension glaucoma

A 41-year-old caucasian male was referred to the Glaucoma clinic at our tertiary referral centre with a diagnosis of normal tension glaucoma after the finding of increased bilateral asymmetrical cup/disc ratios, with normal intraocular pressures. On examination, the authors confirmed the presence of bilateral reduced optic disc rims alongside a left pale residual rim, and a further discovered a positive dyschromatopsia with a bilateral visual field alteration. The left visual field showed a relative scotoma confined to the vertical midline. After initiating investigation for suspected glaucoma, the authors ordered a magnetic resonance imaging that evidenced an internal carotid aneurysm along the ophthalmic segment, stretching across the optic chiasm with a major involvement of the left optic nerve and partial involvement of the right optic nerve. Aneurysm embolisation was performed with complete resolution of signs and symptoms achieved 5 months post-operatively. Despite glaucoma being the most frequent condition causing optic disc atrophy and visual field loss, it is not the only cause. Any atypical visual field defect not in keeping with a glaucomatous field loss should be further investigated. The ophthalmologist should thoroughly assess all signs that could lead to different diagnosis.

Indications for a systemic work-up in glaucoma

Most glaucomas are primary in nature. However, many adult and childhood glaucomas are secondary, and they require systemic evaluation to pick up associated systemic disease. Conditions such as nocturnal hypotension and sleep apnea may contribute to glaucomatous progression, whereas neurologic diseases may mimic normal tension glaucoma based on disc appearance. This review highlights those conditions in which a focused systemic work-up can improve glaucoma management and potentially discover life-threatening disease.

Decision Making for Patients With Concomitant Pituitary Macroadenoma and Ophthalmologic Comorbidity: A Clinical Controversy

BACKGROUND

Coexisting complex visual field defects and serious ophthalmologic comorbidities make the management of the pituitary macroadenomas more challenging. Diffusion tensor imaging (DTI) magnetic resonance imaging that tracks neural fibers in the white matter has been used recently to visualize the impact of different pathologies on cranial nerves. This study explains application of anterior optic pathway tractography for patients with ophthalmologic comorbidities and pituitary adenoma.

METHODS

Two patients with atypical visual field defects caused by nonfunctional pituitary macroadenoma and simultaneous ophthalmologic morbidities (one glaucoma and the other giant cell arteritis) were selected for surgical decompression of the anterior optic apparatus. Standard perimetry and optic pathway DTI were done preoperatively, intraoperatively, and 3 months after surgery.

RESULTS

The nontypical pattern of visual field defect could not differentiate between the ophthalmologic disease and the chiasmatic compression attributable to pituitary macroadenoma as the main cause. Preoperative visual pathway DTI tractography showed lack of decussating chiasmatic fibers in both of the patients. DTI tractography revealed the reappearance of these fibers intraoperatively in one and postoperatively in the other one. Three months after surgery, the visual field and acuity improved and DTI tractography confirmed presence of crossing chiasmatic fibers.

CONCLUSION

Visual pathway DTI tractography is a promising adjunct to the standard perimetry in preoperative assessment of pituitary macroadenoma with serious ophthalmologic comorbidities. It also may be useful in the intraoperative determination of the optic pathway decompression and for following the visual outcome of these patients after surgery.

Power of the metaphor: forty signs on brain imaging

We retrospectively reviewed neuroradiology database at our tertiary-care hospital to search for patients with metaphoric or descriptive signs on brain computed tomography or magnetic resonance imaging. Only patients who had clinical or pathological definitive diagnosis were included in this review.

Comparison of optic disc morphology of optic nerve atrophy between compressive optic neuropathy and glaucomatous optic neuropathy

Objectives

To compare the optic nerve head (ONH) structure between compressive optic neuropathy (CON) and glaucomatous optic neuropathy (GON), and to determine whether selected ONH quantitative parameters effectively discriminate between GON and CON, especially CON cases presenting with a glaucoma-like disc.

Methods

We prospectively assessed 34 patients with CON, 34 age-matched patients with moderate or severe GON, and 34 age-matched healthy control subjects. The quantitative parameters of ONH structure were compared using the Heidelberg Retina Tomograph 2 (HRT2) and Spectralis optical coherence tomography with an enhanced depth imaging method.

Results

The mean and maximum cup depths of CON were significantly smaller than those with GON (P<0.001 and P<0.001, respectively). The distance between Bruch's membrane opening and anterior surface of the lamina cribrosa (BMO-anterior LC) of CON was also significantly smaller than that of glaucoma but was similar to that of the healthy group (P<0.001 and P = 0.47, respectively). Based on Moorfields regression analysis of the glaucoma classification of HRT2, 15 eyes with CON were classified with a glaucoma-like disc. The cup/disc area ratio did not differ between cases of CON with a glaucoma-like disc and cases of GON (P = 0.16), but the BMO-anterior LC and mean and maximum cup depths of CON cases with a glaucoma-like disc were smaller than those in GON (P = 0.005, P = 0.003, and P = 0.001, respectively).

Conclusions

Measurements of the cup depths and the LC depth had good ability to differentiate between CON with a glaucoma-like disc and glaucoma. There was no laminar remodeling detected by laminar surface position in the patients with CON compared to those with GON.

Age-related differences in longitudinal structural change by spectral-domain optical coherence tomography in early experimental glaucoma

PURPOSE

To characterize age-related differences in the magnitude of spectral-domain optical coherence tomography (SD-OCT) structural change in early experimental glaucoma (EG).

METHODS

Both eyes from four young (1.4-2.6 years) and four old (18.6-21.9 years) rhesus monkeys were imaged at least three times at baseline, and then every 2 weeks after laser-induced, chronic, unilateral IOP elevation until the onset of EG (confocal scanning laser tomographic surface change confirmed twice). Two to 20 weeks after EG onset, animals were euthanized and optic nerve axon counts for all eyes were performed. Masked operators delineated retinal and ONH landmarks in 40 radial B-scans from each eye and imaging session to quantify change from baseline in five SD-OCT neural and connective tissue parameters. The effects of EG, age, and EG × age interactions on the magnitude, rate (magnitude per postlaser time), and IOP responsiveness (magnitude per cumulative IOP insult) of postlaser parameter change were individually assessed using general estimating equation models.

RESULTS

Presac SD-OCT RNFLT and minimum rim width change and postmortem axon loss was not significantly different in old compared with young EG eyes. The rate of change and IOP responsiveness of the parameters anterior lamina cribrosa surface depth relative to Bruch's membrane opening (BMO) and BMO depth relative to peripheral Bruch's membrane were significantly lower (P < 0.05) in the old compared with the young EG eyes.

CONCLUSIONS

At similar postlaser times, levels of cumulative IOP insult and axonal damage, SD-OCT-detected ONH connective tissue structural change is greater in young compared with old monkey EG eyes.

Differentiation of compressive from glaucomatous optic neuropathy with spectral-domain optical coherence tomography

PURPOSE

To compare optic disc topography in eyes with compressive optic neuropathy (CON) and open-angle glaucoma (OAG) using spectral-domain (SD) optical coherence tomography (OCT) and Heidelberg retinal tomograph (HRT) (Heidelberg Engineering GmbH, Heidelberg, Germany).

DESIGN

Cross-sectional, observational study.

PARTICIPANTS

A total of 200 eyes from 123 patients with CON (69 eyes) or OAG (58 eyes) and controls (73 eyes).

METHODS

Univariate and multivariate analyses of HRT parameters, SD-OCT circumpapillary retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) parameters.

MAIN OUTCOME MEASURES

Circumpapillary RNFL, OCT ONH parameters, and HRT parameters.

RESULTS

The univariate analysis of OCT parameters demonstrated significant differences between the temporal and nasal quadrants; clock hours 3 (55 vs. 73 μm), 4, 8 (93.9 vs. 70.7 μm), 9, and 10; vertical cup-to-disc ratio (C:D) (0.6 vs. 0.8) and cup volume (0.2 vs. 0.5) (P<0.001) between patients with CON and OAG, respectively. The CON discs were significantly different from normal discs for all OCT parameters except cup volume. The CON discs were not significantly different from normal discs for HRT parameters, except for mean RNFL thickness and cup shape measure. The OAG discs were significantly different from normal discs in all HRT and OCT parameters (P<0.001). Multivariate analysis demonstrated that the OCT 3 o'clock temporal sector, average C:D ratio, vertical C:D ratio, and cup volume measurements were able to differentiate OAG from CON.

CONCLUSIONS

Compressive optic neuropathy is associated with significantly thinner nasal and temporal sectors compared with OAG, whereas OAG results in larger cups and cup volume with OCT measurements. The Heidelberg retinal tomograph is not able to differentiate CON from normal discs.

Clinical characteristics of nonglaucomatous optic disc cupping

Pathological optic disc cupping (ODC) is predominantly referred to as glaucoma; however, it is not only glaucoma that leads to pathological optic disc excavation. A number of other nonglaucomatous diseases also result in optic atrophy and excavation of the optic disc. Therefore, in the present study, the etiology of nonglaucomatous optic disc cupping (NGODC) was analyzed and differentiated from glaucomatous optic disc cupping (GODC). The morphology and clinical data of 19 eyes, from 12 patients exhibiting NGODC, were analyzed. Of the 12 cases, none were diagnosed with glaucoma, four presented with optic neuritis, one with Devic’s disease, one with Leber’s hereditary optic neuropathy, two with pituitary adenoma, one with basal ganglia cerebral hemorrhage, one with cilioretinal artery occlusion associated with central retinal vein occlusion, one with central retinal artery occlusion and the remaining patient exhibited optic nerve injuries. The key features that differentiated NGODC from GODC were the color of the optic disc rim and the correlation between visual field defects and the disc appearance. The focally notched disc also aided in distinguishing between the two disorders. The results of the present study indicated that it is critical to acknowledge that nonglaucomatous diseases also lead to ODC and that distinguishing between them is necessary.

Parapapillary atrophy in patients with intracranial tumours

PURPOSE

To examine size and frequency of parapapillary atrophy (beta zone) in patients with intrasellar or perisellar tumours and a glaucoma-like appearance of the intrapapillary optic disc region.

METHODS

Thirty-four Chinese subjects with intrasellar or perisellar tumours and a glaucoma-like appearance of the intrapapillary optic disc region and 129 age-matched subjects randomly selected from the population-based Beijing Eye Study were enrolled. Beta zone was measured on fundus photographs. Size and location of the tumours were assessed on neuroradiological images.

RESULTS

Beta zone was significantly more common (79 ± 7% versus 46 ± 4%; p = 0.001), and it was significantly larger in the tumour group than in the control group (circumferential extent: 135 ± 99 versus 57 ± 72; p < 0.001; relative area: 1856 ± 1923 versus 759 ± 1390; p = 0.002). The width of the intracerebral tumours was significantly associated with the circumferential extent of beta zone (r = 0.36, p = 0.039) and with the area of beta zone (r = 0.37, p = 0.032). Tumour width, height and depth were significantly (p = 0.001; p = 0.012; and p < 0.001, respectively) larger in the group of patients with beta zone than in the subgroup of patients without beta zone of parapapillary atrophy.

CONCLUSIONS

Patients with large intrasellar or perisellar tumours and a glaucoma-like appearance of the intrapapillary region as compared with a population-based control group had a significantly larger and more frequently occurring beta zone of parapapillary atrophy. It suggests that large parasellar or suprasellar tumours can be associated with typical glaucomatous abnormalities in the parapapillary and intrapapillary region of the optic nerve head. It may give hints for the pathogenesis of glaucomatous optic neuropathy.

[Compressive optic neuropathy secondary to a pituitary macroadenoma]

INTRODUCTION

Pituitary adenoma is a common benign tumor representing 8 to 10% of intracranial mass lesions. The compressive optic neuropathy associated with a pituitary adenoma can be clinically indistinguishable from glaucomatous optic neuropathy.

CASE REPORT

A 56-year-old man with no significant past medical history had noticed a rapid decrease in visual acuity for 6 months. Funduscopic examination revealed glaucoma-like bilateral, asymmetric optic cupping. Brain MRI examination revealed a pituitary tumor compressing the optic chiasm.

CONCLUSION

The diagnosis of a compressive optic neuropathy associated with a pituitary adenoma can be difficult, since it often simulates chronic glaucoma. However, several features should alert the clinician to the possibility of a compressive optic neuropathy and prompt neuroimaging, in order to obtain earlier diagnosis and treatment.

A biomechanical paradigm for axonal insult within the optic nerve head in aging and glaucoma

This article is dedicated to Rosario Hernandez for her warm support of my own work and her genuine enthusiasm for the work of her colleagues throughout her career. I first met Rosario as a research fellow in Harry Quigley's laboratory between 1991 and 1993. Along with Harry, John Morrison, Elaine Johnson, Abe Clark, Colm O'Brien and many others, Rosario's work has provided lamina cribrosa astrocyte cellular mechanisms that are biomechanically plausible and in so doing provided credibility to early notions of the optic nerve head (ONH) as a biomechanical structure. We owe a large intellectual debt to Rosario for her dogged persistence in the characterization of the ONH astrocyte and lamina cribrosacyte in age and disease. Two questions run through her work and remain of central importance today. First, how do astrocytes respond to and alter the biomechanical environment of the ONH and the physiologic stresses created therein? Second, how do these physiologic demands on the astrocyte influence their ability to deliver the support to retinal ganglion cell axon transport and flow against the translaminar pressure gradient? The purpose of this article is to summarize what is known about the biomechanical determinants of retinal ganglion cell axon physiology within the ONH in the optic neuropathy of aging and Glaucoma. My goal is to provide a biomechanical framework for this discussion. This framework assumes that the ONH astrocytes and glia fundamentally support and influence both the lamina cribrosa extracellular matrix and retinal ganglion cell axon physiology. Rosario Hernandez was one of the first investigators to recognize the implications of this unique circumstance. Many of the ideas contained herein have been initially presented within or derived from her work (Hernandez, M.R., 2000. The optic nerve head in glaucoma: role of astrocytes in tissue remodeling. Prog Retin Eye Res. 19, 297-321.; Hernandez, M.R., Pena, J.D., 1997. The optic nerve head in glaucomatous optic neuropathy. Arch Ophthalmol. 115, 389-395.).

Glaucoma-like optic neuropathy in patients with intracranial tumours

PURPOSE

To examine frequency and associated factors of glaucoma-like appearance of the optic nerve head in patients with intrasellar, suprasellar or parasellar tumours.

METHODS

This retrospective clinical observational study included patients who were consecutively treated for intrasellar tumours (n = 143), suprasellar tumours (n = 321), parasellar tumours (n = 36) or retrosellar tumour (n = 1), and all of whom had undergone fundus photography and full-threshold visual field examination. The tumour spectrum included 336 pituitary gland tumours, 32 meningiomas, 89 craniopharyngiomas, 9 chiasmal gliomas and 35 other types of tumours or lesions. An age-matched control group was formed from the population-based Beijing Eye Study. Using fundus photographs and visual field examinations, glaucoma was defined by a neuroretinal rim shape not following the ISNT rule (Disc glaucoma group) and by an abnormal rim shape plus glaucoma-like visual field defects (Field glaucoma group). Type and size of the tumours were assessed on neuroradiological images.

RESULTS

Five-hundred and one patients fulfilled the inclusion criteria. Disc glaucoma and Field glaucoma were detected significantly more frequently in the study population [34 (6.8%) patients and 31 (6.3%) patients, respectively] than in the population-based control group of the same ethnicity (1.3% ± 0.5%; p < 0.001). In multivariate analysis, presence of Disc glaucoma [odds ratio (OR) = 2.64; p = 0.016] and presence of Field glaucoma (OR = 3.01; p = 0.027) were significantly associated with tumour location [suprasellar > parasellar > intrasellar]. The same held true for tumour width (OR = 1.08; p = 0.002; and OR = 1.08; p = 0.003, respectively).

CONCLUSIONS

Large perisellar tumours were associated with a glaucoma-like appearance of the optic nerve head in eyes. It may diagnostically and pathogenetically be of importance.

Optic nerve abnormalities in children: a practical approach

Evaluation of children with optic nerve abnormalities is challenging. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, and genetic testing are helpful in the diagnosis and management of these patients. Importantly, many optic nerve problems are not isolated but occur in association with systemic and central nervous system anomalies. The ophthalmologist thus plays a critical role in recognizing patients who warrant systemic and neurologic assessment.

Differentiating glaucomatous from non-glaucomatous optic nerve cupping by optical coherence tomography

BACKGROUND

In clinical practice, the differentiation of glaucomatous from non-glaucomatous cupping can be difficult, even for experienced observers. The purpose of this study was to evaluate the role of optical coherence tomography (OCT) in differentiating glaucomatous from non-glaucomatous optic nerve cupping in a cross-sectional pilot study.

METHODS

Eleven consecutive patients presenting to the Duke Eye Center from September 2007 to July 2008 with non-glaucomatous optic nerve cupping and 12 patients with glaucomatous optic nerve cupping were identified. All patients underwent Stratus® OCT imaging: fast macular map, fast retinal nerve fiber layer (RNFL) 3.4 thickness, and fast optic disc protocols. Automated visual field perimetry was performed on the date of OCT scan in non-glaucomatous cupping patients, and from 0-9 months of scan date in glaucoma patients. Eyes were matched by optic nerve cup-to-disc area ratio; average and mean deviation were calculated for each variable.

RESULTS

For a similar average RNFL, patients with non-glaucomatous optic nerve cupping had lower nasal and temporal RNFL thickness, as well as lower macular thickness and volume compared to patients with glaucomatous optic nerve cupping.

CONCLUSION

OCT appears to be a useful technology in differentiating glaucomatous from non-glaucomatous optic nerve cupping. The pattern of RNFL loss appears more diffuse in non-glaucomatous optic nerve cupping compared to glaucomatous optic nerve cupping. Future studies with larger sample size and specific neuro-ophthalmic causes of optic nerve cupping may further elucidate the role of OCT in this clinical setting.

Brain-derived neurotrophic factor in patients with normal-tension glaucoma

PURPOSE

The aim of this study was to detect and measure brain-derived neurotrophic factor (BDNF) in the tears of normal subjects and patients with normal-tension glaucoma (NTG).

MATERIALS AND METHODS

Twenty patients with NTG as the case group and 20 normal subjects with the same age range as the control group were tested. The control group consisted of 16 men and 4 women, ranging in age from 40 to 75, without any apparent ocular or systemic disease. The case group consisted of 15 men and 5 women, ranging in age from 45 to 74. BDNF levels in tears were determined by enzyme-linked immunosorbent assay using monoclonal antibodies specific for BDNF (R&D Systems, Minneapolis, Minnesota).

RESULTS

The mean level of BDNF detected in the tears of the normal subjects was 77.09 +/- 4.84 ng/mL and the BDNF levels in the tears of case group were 24.33 +/- 1.48 ng/mL (P < 0.001).

CONCLUSION

We suggest that BDNF in the tears might be a useful biochemical marker for early detection of normal-tension glaucoma (NTG).

Evaluating optic nerve damage: pearls and pitfalls

Primary open-angle glaucoma is a progressive optic neuropathy involving loss of retinal ganglion cells and their axons at the level of the optic nerve head. This change manifests as thinning and excavation of the neural tissues and nerve fiber layer. Therefore, it has long been known that the structural appearance of the optic nerve head is paramount to both glaucoma diagnosis and to the detection of progression [1-4]. Quantitative imaging methods such as Heidelberg Retinal Tomography (HRT) and Ocular Coherence Tomography (OCT) show great promise for the diagnosis and management of glaucoma and as these technologies continue to improve, they will become more important in the care of glaucoma. However, these tests cannot replace good clinical examination and indeed they depend upon clinical correlation for correct interpretation. Thus, careful and systematic clinical examination of the optic nerve remains a cornerstone of glaucoma management. In this paper, we outline a few pearls for the examination of the optic nerve and some of the pitfalls to be avoided in optic disc examination.