The Influence of Volume and Anatomic Location of Optic Disc Drusen on the Sensitivity of Autofluorescence

Understanding pseudopapilledema on spectral domain optical coherence tomography

Purpose

Optic nerve head drusen (ONHD), peripapillary hyperreflective ovoid mass-like structures (PHOMS), and horizontal hyperreflective lines (HHL) are commonly seen in eyes with pseudopapilledema on enhanced depth imaging (EDI) spectral domain optical coherence tomography (SDOCT). The objective of this study is to assess the frequency of ONHD, PHOMS, and HHL on spectral domain OCT in the eyes diagnosed to have pseudopapilledema.

Methods

A retrospective case-control study included patients diagnosed as pseudopapilledema and had EDI SD OCT imaging of the optic nerve head (n = 48 eyes) and controls (n = 20 eyes). OCT scans through the optic nerve head were studied to diagnose ONHD, HHL, and PHOMS. One proportion z test was used to find the difference in proportions.

Results

Forty eight eyes of 27 subjects were studied. ONHD as described by the optic disc drusen Studies consortium was noted in 19 eyes (39.48%), P value-0.032, PHOMS in 31 eyes (64.6%), P value 0.043, HL in 19 eyes (39.48%), P value 0.032, and none of the normals had ONHD, PHOMS, and HHL.

Conclusions

PHOMS are more frequently seen than ONHD and HHL in eyes with pseudopapilledema.

A Comparison of Diagnostic Accuracy of Imaging Modalities to Detect Optic Disc Drusen: The Age of Enhanced Depth Imaging Optical Coherence Tomography

PURPOSE

To identify the most accurate diagnostic imaging modality to detect optic disc drusen (ODD) between B-scan ultrasonography (US), fundus photography, fundus autofluorescence (FAF), and enhanced depth imaging optical coherence tomography (EDI-OCT).

DESIGN

Comparative diagnostic analysis.

METHODS

Two hundred five eyes of 105 patients referred to 2 tertiary care neuro-ophthalmology clinics for suspected ODD were recruited: 108 eyes had ODD and 97 did not have ODD. All eyes received a full in-person ophthalmic exam with 3D view of the optic nerve and all 4 imaging modalities. Images were independently reviewed by 3 masked neuro-ophthalmologists to determine the presence or absence of ODD. Final interpretation was made through consensus. The reference standard was defined as the attending ophthalmologist's clinical judgement based on open chart review, with access to all image modalities and clinical information, including disease course. Main outcome measures were sensitivity, specificity, accuracy, and precision for each imaging modality. Examiner confidence was quantified as the proportion of eyes in which the reviewers were certain of their decision.

RESULTS

The EDI-OCT had the highest sensitivity and accuracy (95%, 97%) to detect ODD, compared with FAF (84%, 92%), US (74%, 86%), and fundus photography (38%, 66%), respectively. All image modalities had high specificity (> 97%) and precision (> 93%). The EDI-OCT also had highest examiner confidence (96%) compared with all others (88%).

CONCLUSIONS

Among all modalities, EDI-OCT was the imaging modality with the highest diagnostic utility for the detection of ODD and should be considered as the preferred initial diagnostic modality.

The Role of Optical Coherence Tomography Angiography in Optic Nerve Head Edema: A Narrative Review

Optic nerve head (ONH) edema is a clinical manifestation of many ocular and systemic disorders. Ocular and central nervous system imaging has been used to differentiate the underlying cause of ONH edema and monitor the disease course. ONH vessel abnormalities are among the earliest signs of impaired axonal transportation. Optical coherence tomography angiography (OCTA) is a noninvasive method for imaging ONH and peripapillary vessels and has been used extensively for studying vascular changes in ONH disorders, including ONH edema. In this narrative review, we describe OCTA findings of the most common causes of ONH edema and its differential diagnoses including ONH drusen.

Updates on ophthalmic imaging features of optic disc drusen, papilledema, and optic disc edema

Purpose of review

Optic nerve head elevation can be associated with vision loss. This review provides an update regarding key features of optic disc drusen (ODD) compared with papilledema from increased intracranial pressure and optic disc edema from other causes.

Recent findings

Clinical history and funduscopic examination are not sufficient to correctly diagnose different causes of optic nerve head elevation. Multimodal ophthalmic imaging is noninvasive and should be used as first-line diagnostic testing to distinguish optic disc edema or papilledema from pseudoedema. Advanced ophthalmic imaging, including enhanced depth imaging optical coherence tomography (EDI-OCT) and autofluorescence imaging, can visualize ODD at high resolution and determine whether there is optic disc edema. OCT angiography does not require contrast and can rapidly visualize papillary, peripapillary, and macular microvasculature and identify important vascular biomarker of ischemia and, potentially, visual prognosis.

Summary

Multimodal ophthalmic imaging can help in the diagnosis of ODD and optic disc edema and identify patients at high risk of vision loss and neurological issues in order to ensure appropriate diagnosis and treatment.

Progression Over 5 Years of Prelaminar Hyperreflective Lines to Optic Disc Drusen in the Copenhagen Child Cohort 2000 Eye Study

BACKGROUND

The purpose of the study was to examine 5-year changes in eyes with optic disc drusen at baseline on optical coherence tomography (OCT) scans and the relation of incident drusen to hyperreflective prelaminar lines.

METHODS

The study included children who presented at baseline, when participants were aged 11-12 years, and again 5 years later. Grading for optic disc drusen was made in all. Grading for prelaminar lines was made in all children at follow-up and in eyes with optic disc drusen at baseline. Analyses included associations with scleral canal diameter at baseline in all children with optic disc drusen and a nested control group of 115 children without optic disc drusen. Data are reported as the number of children having at least one drusen or at least one hyperreflective line per person.

RESULTS

The analysis included 724 children who attended both rounds of the study. Of these, 11 (1.5%) had optic disc drusen at baseline. Five additional children had developed optic disc drusen at follow-up, whereas optic disc drusen had disappeared in none, so that 16 (2.2%) children had optic disc drusen in one or both eyes at follow-up. Children with optic disc drusen at the 5-year follow-up had had a mean scleral canal diameter of 1,364 µm (interquartile range [IQR] 81 µm), compared with 1,457 µm (IQR 197) µm in 115 nested controls without optic disc drusen (P < 0.001). Optic disc drusen at follow-up were associated with more hypermetropic refraction. All children who had optic disc drusen at follow-up also had prelaminar hyperreflective lines. In addition, such lines were found at follow-up in 24 of the remaining 708 children without optic disc drusen (P < 0.001). Prelaminar hyperreflective lines with or without optic disc drusen were associated with a narrower scleral canal (diameter 1,364 µm, IQR 119 µm) compared with absence of prelaminar lines (1,486 µm, IQR 206 µm; P < 0.0001).

CONCLUSION

This study provides the first evidence from a prospective study that small optic discs and prelaminar hyperreflective lines on OCT are risk factors for the development of optic disc drusen. The association between prelaminar hyperreflective lines, hypermetropia, and a narrow scleral canal supports that a crowded disc is an essential predisposing factor for the development of optic disc drusen.

Prevalence of Optic Disc Drusen in Young Patients With Nonarteritic Anterior Ischemic Optic Neuropathy: A 10-Year Retrospective Study

BACKGROUND

Nonarteritic anterior ischemic optic neuropathy (NAION) in young patients (age ≤50) accounts for a minority of all cases of NAION and is more highly associated with crowding of the optic nerves and bilateral involvement than NAION in older patients. Optic disc drusen (ODD) are likewise associated with crowded optic nerves and are located in the prelaminar optic nerve head where they could contribute to NAION pathogenesis. The purpose of this study was to determine the prevalence of ODD in the eyes of young NAION patients using modern imaging methods and to compare it to the baseline 1.8%-2.0% prevalence of ODD in the general population.

METHODS

In this retrospective study, all young NAION patients (ages 18-50 years, inclusive) seen in 2 tertiary care neuro-ophthalmology clinics (in London, Canada and Copenhagen, Denmark) in the ten-year interval between April 1, 2009, and March 31, 2019, were identified and their medical charts reviewed. Patients were included in the study if ODD were diagnosed by any method (including ophthalmoscopy, ultrasound [US], fundus autofluorescence [FAF], computed tomography [CT], or any optical coherence tomography [OCT] method), or if ODD were excluded by enhanced-depth imaging OCT (EDI-OCT) using the ODD Studies (ODDS) Consortium protocol. The presence or absence of ODD was recorded for each eye.

RESULTS

There were 37 eligible patients (74 eyes). Mean age of NAION onset was 38.5 ± 10.0 years, and 23 patients (62%) were men. Patients had undergone the following methods of ODD detection: ophthalmoscopy (37 patients), EDI-OCT (36 patients), FAF (31 patients), US (9 patients), and CT orbits (8 patients). We found a prevalence of ODD of 56.7% in NAION-affected patients and 53.3% in NAION-affected eyes. Only 35.9% of ODD were visible on ophthalmoscopy. Twenty of 21 ODD patients (95.2%) had bilateral ODD. Age of onset and sex did not differ significantly between the ODD-positive group and the ODD-negative group. EDI-OCT outperformed any combination of ophthalmoscopy, US, FAF, and CT at detecting ODD.

CONCLUSION

ODD were found with much higher prevalence in young patients with NAION than in the general population and were usually bilateral and buried. ODD may contribute to NAION pathogenesis by exacerbating an underlying compartment syndrome in the crowded "disc at risk." EDI-OCT may be the best imaging modality for ODD detection in future studies.

Multimodal Imaging Features of Optic Disc Drusen

PURPOSE

To identify key en face multimodal imaging features of optic disc drusen (ODD).

DESIGN

Retrospective cross-sectional study.

METHODS

Setting: a single academic center. Patient orStudyPopulation: 786 patients (10-82 years of age) with diagnostic codes for optic disc drusen (ODD) in clinical notes extracted using natural language processing. Intervention orObservationProcedures: color fundus imaging, green-light and blue-light fundus autofluorescence (FAF), near-infrared reflectance (NIR), and enhanced-depth imaging optical coherence tomography (EDI-OCT). MainOutcomeMeasurements: Ophthalmic imaging characteristics and sensitivity of en face imaging compared with EDI-OCT.

RESULTS

A total of 38 patients (61 eyes) had high-quality EDI-OCT scans and en face multimodal imaging. Green-light FAF imaging had the highest diagnostic sensitivity (96.8%) for ODD and showed homogeneous hyperautofluorescence, whereas blue-light FAF imaging had heterogeneous brightness, which helped differentiate superficial from deep ODD. Blue-light FAF (93.5%) and NIR (91.8%) imaging were also sensitive tests and revealed papillary and peripapillary features that were not well seen on green-light FAF, including the size and depth of ODD, morphology of the optic disc, and common ODD-associated structures such as horizontal hyper-reflective lines and peripapillary hyper-reflective ovoid mass-like structures (PHOMS). Color fundus imaging had the lowest sensitivity (82%). There was good inter-rater reliability for all en face imaging modalities (P < .0001 for all).

CONCLUSIONS

In en face imaging, green-light FAF had the highest sensitivity for the diagnosis of ODD, whereas blue-light FAF and NIR images provided more information regarding the severity, location, depth, and size of ODD. In eyes that are negative on green-light FAF, EDI-OCT should be performed and provides the highest-resolution characterization of the entire optic disc to assess or rule out ODD.

Recent advances and future directions on the use of optical coherence tomography in neuro-ophthalmology

Optical coherence tomography (OCT) is a noninvasive imaging technique used to qualitatively and quantitatively analyze various layers of the retina. OCT of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) is particularly useful in neuro-ophthalmology for the evaluation of patients with optic neuropathies and retrochiasmal visual pathway disorders. OCT allows for an objective quantification of edema and atrophy of the RNFL and GCIPL, which may be evident before obvious clinical signs and visual dysfunction develop. Enhanced depth imaging OCT allows for visualization of deep structures of the optic nerve and has emerged as the gold standard for the detection of optic disc drusen. In the evaluation of compressive optic neuropathies, OCT RNFL and GCIPL thicknesses have been established as the most important visual prognostic factor. There is increasing evidence that inclusion of OCT as part of the diagnostic criteria for multiple sclerosis (MS) increases its sensitivity. Moreover, OCT of the RNFL and GCIPL may be helpful in the early detection and monitoring the treatment of conditions such as MS and Alzheimer's disease. OCT is an important aspect of the neuro-ophthalmologic assessment and its use is likely to increase moving forward.

Young Adults With Anterior Ischemic Optic Neuropathy: A Multicenter Optic Disc Drusen Study

PURPOSE

Optic disc drusen (ODD), present in 2% of the general population, have occasionally been reported in patients with nonarteritic anterior ischemic optic neuropathy (NA-AION). The purpose of this study was to examine the prevalence of ODD in young patients with NA-AION.

DESIGN

Retrospective, cross-sectional multicenter study.

METHODS

All patients with NA-AION 50 years old or younger, seen in neuro-ophthalmology clinics of the international ODDS (Optic Disc Drusen Studies) Consortium between April 1, 2017, and March 31, 2019, were identified. Patients were included if ODD were diagnosed by any method, or if ODD were excluded by enhanced-depth imaging optical coherence tomography (EDI-OCT) using ODDS Consortium guidelines. NA-AION eyes with ODD were termed "ODD-AION"; those without were termed "NODD-AION".

RESULTS

A total of 65 patients (127 eyes) with NA-AION were included (mean 41 years old). Of the 74 eyes with NA-AION, 51% had ODD-AION, whereas 43% of fellow eyes without NA-AION had ODD (P = .36). No significant differences were found between ODD-AION and NODD-AION eyes in terms of Snellen best-corrected VA or perimetric mean deviation. According to EDI-OCT results, 28% of eyes with NODD-AION had peripapillary hyperreflective ovoid mass-like structures (PHOMS); 7% had hyperreflective lines, whereas 54% with ODD-AION had PHOMS; and 66% had hyperreflective lines (P = .006 and P < .001, respectively).

CONCLUSIONS

Most of these young NA-AION patients had ODD. This indicates that ODD may be an independent risk factor for the development of NA-AION, at least in younger patients. This study suggests ODD-AION be recognized as a novel diagnosis.

The Utility of Fundus Fluorescein Angiography in Neuro-Ophthalmology

While its use is still widespread within the medical retina field, fundus fluorescein angiography (FFA) is increasingly falling out of favour in the investigation of neuro-ophthalmological disease, with the introduction of new technologies, particularly optical coherence tomography. FFA does, however, provide useful diagnostic and prognostic information in many neuro-ophthalmological diseases including papilloedema, pseudo-papilloedema, optic neuropathies and central retinal artery occlusion to name a few. We aim to summarise the main FFA findings in each of these conditions and highlight where FFA is of most use in providing complementary information to other modes of investigation.