Visual field defects due to optic disk drusen in children

[Opticopathies in the differential diagnosis of retinal diseases - part 2]

Due to the close anatomical, functional and trophic relationships between the optic nerve and retina, a wide variety of diseases affecting both structures have reciprocal effects on each other, which must be considered in the differential diagnosis to avoid misdiagnosis. Therefore, it is essential to assess pathological changes in both structures in context to differentiate the type and location of the primary lesion from its consequences, as well as to correctly classify coincidences and disease-specific lesion patterns in both organ components.This article highlights the typical symptom constellations and lesion patterns of optic neuropathies and retinopathies. An attempt is made to identify the reciprocal characteristic relationships of the respective lesions in both structures in various disease groups, as well as to present their respective roles in the differential diagnosis.In this second part, acquired optic neuropathies in the context of vascular and systemic diseases and possible accompanying retinal findings, as well as symptom constellations and courses, are differentiated, discussing arteritic and non-arteritic (anterior) optic neuropathies, their causes and differential diagnosis. The combined involvement of the optic nerve and retina in the context of posterior infectious and non-infectious uveitis is also shown. Finally, various dysgenetic optic neuropathies, their differentiation and possible retinal sequelae are presented.It is demonstrated and exemplified how important it is in general, but also specifically in regard to the disease groups discussed in this article, to have a careful and targeted diagnostic approach in each case, considering both the retinal and optic nerve findings, in order to avoid misdiagnosis.

Application of Optical Coherence Tomography Angiography in True and Pseudo-Optic Disc Swelling

Purpose

We evaluated the optic disc microvasculature in healthy subjects and patients with optic nerve head drusen (ONHD), active papilledema, and acute nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography angiography (OCTA).

Methods

This prospective, comparative case series included sixteen eyes with ONHD, thirty-one eyes with active papilledema, sixteen eyes with acute NAION, and thirty-two healthy eyes. The Optovue AngioVue OCT and OCTA Imaging System recorded peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density maps from the radial peripapillary capillary (RPC) slab.

Results

Average RNFL thicknesses were greater in eyes with ONHD, papilledema, and NAION compared to control eyes (all Ps < 0.001), but this parameter did not differ among patient groups. The mean peripapillary vessel density did not differ between the ONHD and control groups (P=1.000), nor between the NAION and papilledema groups (P=0.216). However, this value in the ONHD and control groups was significantly higher than in the NAION and papilledema groups (all Ps < 0.05).

Conclusion

RPC density is influenced during the progression of conditions such as ONHD, papilledema, and NAION. Although a decrease in vessel density values has been observed in cases of true disc edema, further research is necessary to assess the potential of OCTA in differentiating between true and pseudo-optic disc edema.

Visual Field Defects in Patients With Optic Nerve Head Drusen

Background Optic nerve head drusen (ONHD) are acellular deposits in the optic nerve head, whose pathophysiology remains not fully understood. Most patients with ONHD have visual field (VF) defects. This study aims to describe the VF defects observed in patients with ONHD and to compare the anatomical and functional impairment between visible and buried ONHD. Methods Patients with ONHD were retrospectively studied. The retinal nerve fiber layer (RNFL) average thickness and the ganglion cell complex (GCC) average thickness were collected from optical coherence tomography data. Visual field index (VFI), mean deviation (MD), and pattern standard deviation (PSD) were collected from 30-2 standard automated perimetry. An abnormal VF test was defined as having a Glaucoma Hemifield Test outside normal limits and/or a PSD with a p-value<5%. Eyes with superficial or buried ONHD based on visibility by slit-lamp ophthalmoscopy were compared. Results Sixty-six eyes of 36 patients were included in the study. The mean age was 39.6 ± 2.5 years. Forty-nine eyes (81.7%) presented a VF defect: concentric VF constriction in 19 (38.8%), arcuate scotoma in 16 (32.7%), enlarged blind spot in 9 (18.4%), unspecific VF defect in 8 (16.3%), and nasal step in 3 (6.1%). Thirty-four eyes (51.5%) had superficial ONHD and 32 eyes (48.5%) had buried ONHD. Patients with superficial ONHD were significantly older (p<0.001) and presented a significantly lower VFI (p=0.010), lower MD (p=0.002), higher PSD (p<0.001), thinner GCC (p<0.001), and thinner RNFL (p<0.001) than patients with buried ONHD. VF defects were present in 90.6% of eyes with superficial ONHD and 71.4% of eyes with buried ONHD (p=0.113). The type of VF defects differed between groups (p=0.020). Conclusions Functional and structural impairment is more evident in eyes with superficial ONHD, maybe because the presence of calcification leads to greater axonal damage. Buried ONHD is more prevalent in younger patients, progressing to a superficial location and becoming calcified with age.

The visual morbidity of optic nerve head drusen: a longitudinal review

BACKGROUND

The ophthalmologic complications of optic nerve head drusen (ONHD) in adults have been documented, whereas data on the degree of visual morbidity from OHND in children are limited.

METHODS

The medical records of all patients diagnosed with ONHD at a single, tertiary care ophthalmology department from January 1, 2010, until July 1, 2018, were reviewed retrospectively. Patients were identified using ICD-9 and ICD-10 codes. Inclusion criteria were age ≤18 years of age and formal documentation of ONHD by ancillary testing.

RESULTS

A total of 213 patients (386 eyes with ONHD) met inclusion criteria. Mean age at diagnosis was 10.13 ± 4.09 years, and mean follow-up was 2.76 ± 2.91 years. Formal visual fields were available for 208 eyes. Repeatable visual field defects were noted in 24 eyes (11.5%). The most common defect was a nasal step, which occurred in 11 eyes (45.8%). Fifteen eyes had visual field defects at presentation, and 9 eyes developed field loss within 1.39 ± 0.55 years of diagnosis. There was no correlation found between intraocular pressure and degree of visual field loss. Choroidal neovascular membranes were clinically apparent in 5 eyes and treatment was required in 3 eyes. Nonarteritic ischemic optic neuropathy developed in 2 eyes.

CONCLUSIONS

Visual morbidity associated with ONHD in children is common and may develop in a short period of time after initial diagnosis. There was no correlation found with intraocular pressure.

Enhanced Depth Imaging Optical Coherence Tomography Technology Reveals a Significant Association Between Optic Nerve Drusen Anterior Displacement and Retinal Nerve Fiber Layer Thinning Over Time

BACKGROUND

Optic disc drusen (ODD) are a dynamic phenomenon, and their appearance, size, and relative location may change. The purpose of this study is to evaluate and quantify the longitudinal changes of buried ODD with enhanced depth imaging (EDI) optical coherence tomography (OCT) over time.

METHODS

ODD were analyzed with Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) and EDI technology. The peripapillary retinal nerve fiber layer (RNFL) thickness was also measured. The size and depth of ODD were compared between the baseline and study visit (at least 2 years of follow-up), and the changes were correlated with mean RNFL thickness. The repeatability, coefficient of variation, and cutoff values for size and depth on EDI-OCT were calculated.

RESULTS

Of 21 previously identified patients with ODD, only 12 patients (21 eyes) met the most recent diagnostic criteria according to the ODD Studies Consortium recommendations for using OCT-EDI technology. The 21 eyes were reanalyzed after a mean period of 44.7 ± 13.2 months (range: 24-71 months). Overall, 132 ODD were evaluated with a mean of 6.1 ± 2.5 ODD per eye and 1.9 ± 1.1 ODD per scan. Overall, we found a significant forward movement of the drusen between visits (P = 0.01). Most drusen (67.4%) moved anteriorly, and in approximately one-third (35.6%), this displacement exceeded the cutoff value (64.28 µm). Furthermore, we found a significant correlation between ODD shallowing and RNFL thinning during the follow-up (P ≤ 0.03; R ≥ 0.370). We did not find any significant changes in size measurements (P = 0.10) over time.

CONCLUSIONS

In approximately one-third of buried ODD, a significant anterior movement occurred over 2 years of follow-up, and this movement was associated with significant RNFL thinning. By contrast, no significant change was detected in the size of the buried ODD.

DIAGNOSTICS OF OPTIC DISC DRUSEN IN CHILDREN WITH SWEPT SOURCE OCT IMAGING

AIM

The aim of this retrospective study is to compare two methods of optic disc drusen imaging in pediatric patients - new swept source OCT technology with the B-scan ultrasonography, which has been assumed to be a gold standard in diagnosing optic disc drusen, and to compare pRNFL thickness in children with optic disc drusen and control group.

METHODS

14 eyes of 8 pediatric patients in whom optic disc drusen were confirmed by either B-scan ultrasonography, or swept-source OCT, were included in the study. We compared the sensitivity of these two imaging methods. Then we compared an average pRNFL thickness and pRNFL thickness in all four quadrants of our study group with the control group. Two statistical methods were used in data analysis - Mann-Whitney a Kruskal-Wallis test.

RESULTS

The difference between SS-OCT and B-scan ultrasonography was not statistically significant in diagnosing optic disc drusen. Average pRNFL thickness was 135.29 ± SD 31.2 &#956;m in eyes with optic disc drusen, which is 24.15 % higher than in control group (p = 0.00214; p = 0.00207). pRNFL thickness of temporal (p = 0.0001; p = 0.0001), superior (p = 0.03486; p = 0.03361) and inferior (p = 0.00652; p = 0.00627) quadrant was statistically significantly higher in comparison with healthy controls, whereas the difference of pRNFL thickness in nasal quadrant was not statistically significant between the study and control group (p = 0.09692; p = 0.0947).

CONCLUSION

Swept source OCT is a promising new "gold standard" in optic disc drusen diagnostics in pediatric patients. An increase in pRNFL thickness values does not always confirm papilloedema as optic disc drusen may be the cause. Direct visualisation of optic disc drusen by swept source OCT can aid in differentiation from true papilloedema.

Kinetic and static perimetry after 16 years and additional OCT-A analysis in eyes with long-lasting optic disc drusen

The aim of the study is to evaluate the progression of visual field (VF) defects over 16 years of observation and to assess abnormalities in vessels and retinal nerve fibre layer (RNFL) thickness in patients with optic disc drusen (ODD). Both static automated perimetry (SAP) and semi-automated kinetic perimetry (SKP) were performed in 16 eyes of 8 patients (mean age 54 years) with ODD among 26 eyes of 13 patients examined 16 years before. The area of I2e, I4e, III4e, and V4e isopters was measured in deg2. The MD and PSD parameters were estimated using SAP. Optical coherence tomography angiography (OCT-A) was additionally performed in 16 ODD eyes and 16 eyes of 8 healthy subjects to estimate the RNFL thickness and vessel density of the optic nerve disc and the macula. The differences in all isopter areas of SKP and SAP parameters after 16 years were not significant. The analysis of OCT-A showed a significant reduction of the vessel density and RNFL of the peripapillary area in each segment in patients with ODD, compared with the control group. The highest reduction of RNFL was observed in the superior segment of the optic disc area (92.56μm vs 126.63μm) also the macular thickness was decreased in ODD patients, compared with the control group. In the macula, there was a significant vascular defect in the whole superficial layer and in the parafoveal deep layer. A strong significant correlation of the parafoveal deep plexus with MD and PSD parameters was detected. In conclusion, VF loss due to ODD after 16 years of the follow-up was not significant both in SKP and SAP. ODD caused a reduced vessel density and RNFL, as well as macular thickness in OCT-A. SAP parameters were influenced by parafoveal deep plexus.

Peripapillary vessel density in pediatric cases with buried optic disk drusen

BACKGROUND

To evaluate the retinal nerve fiber layer (RNFL) and peripapillary vascular density (VD) changes in the pediatric group with optic disk drusen (ODD).

METHODS

Sixty eyes of 30 patients with buried ODD referred by the pediatric or neurology physicians to ophthalmology clinic with a preliminary diagnosis of papillary edema were included in this retrospective study. Sixty eyes of 30 healthy children were included as the control group. Thickness of RNFL (micrometer) and VD percentages (%) of the superior, inferior, nasal, and temporal quadrants of the peripapillary region of all cases were evaluated with optical coherence tomography angiography (OCT-A) device.

RESULTS

The study and control groups were homogeneous in terms of age and gender. VD values were significantly lower in the study group for all four quadrants, when compared to controls (p < 0.001, p < 0.001, p = 0.003, and p < 0.001, for inferior, superior, nasal, and temporal quadrants, respectively. For RFNL thickness measurements, a significant difference between groups was only evident for the nasal quadrant, where the study group had significantly higher nasal RFNL thickness (p = 0.001).

CONCLUSION

This study detected decreases in peripapillary VD values in all quadrants and peripapillary RNFL thickening in nasal quadrant in pediatric cases with buried drusen compared to healthy controls. Further studies are necessary to reveal the effects of drusen pathogenesis on optic nerve head perfusion and to understand the underlying mechanisms of related complications.

Microvascular alterations in children with optic disk drusen evaluated by optical coherence tomography angiography

PURPOSE

To asses changes in vessel density (VD) in children with optic disk drusen (ODD) using swept source optical coherence tomography angiography (OCTA).

METHODS

Cross-sectional study of 27 eyes with ODD compared with age-matched controls. Peripapillary and macular VD were measured in the superficial retinal capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC). The correlation between VD changes with alterations in retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and visual field (VF) was analyzed.

RESULTS

Mean participant age was 12.5 ± 3.3 years (range, 7-18 years); 63% was females. In the patients vs. controls, median central peripapillary VD was 52.9% vs. 50.6% (p = 0.63) for SCP; 48.1% vs. 53.8% (p = 0.017) for DCP; and 17.0% vs. 28.2% (p = 0.0037) for CC, respectively. VD in the superior and nasal CC layers was significantly lower in the patients (36.3% vs. 56.2%; p < 0.001) and (60.4% vs. 70.3%, p < 0.001), respectively. No significant differences were observed for VD in the macular region. The RNFL was thinner in eyes with superficial drusen versus controls (87 vs. 111 μm; p < 0.001). No significant differences between were observed in GCL thickness (p = 0.13). Nasal SCP and nasal RNFL VD were moderately correlated (r = 0.54, p < 0.01), while mean VF deviation was strongly correlated with median SCP VD in patients with superficial drusen (r = 0.9, p = 0.03).

CONCLUSION

Impaired VD was observed in the peripapillary nasal CC in patients with ODD; this impairment was associated with a decreased RNFL thickness. Nasal SCP VD and RNFL thickness were moderately correlated in patients with ODD.

Optic disc drusen in children: morphologic features using EDI-OCT

AIMS

This study aimed to investigate morphologic features of optic disc drusen (ODD) and peripapillary hyperreflective ovoid mass-like structures (PHOMS) in children, using enhanced depth imaging optical coherence tomography (EDI-OCT). It also assessed if the presence of these features were associated with decreased peripapillary retinal nerve fibre layer (RNFL) thickness.

METHODS

Retrospective observational study of children with ODD. All subjects underwent complete ophthalmic examination and multimodal imaging. ODD were identified on EDI-OCT as circumscribed hyporeflective spheroidal elements located in front of lamina cribrosa, fully or partially surrounded by a hyperreflective border. PHOMS were identified as hyperreflective ovoid structures located in the peripapillary circumference. Both associations between ODD and RNFL loss and PHOMS and RNFL loss were tested using chi-squared test.

RESULTS

In total, 38 eyes of 20 children were analysed. PHOMS were present in 90% of patients. ODD and PHOMS were predominantly found in the nasal, superonasal and inferonasal sectors. A significant positive association was found between ODD and decreased RNFL thickness in the nasal (p = 0.02), superonasal (p = 0.05) and inferotemporal (p = 0.04) sectors. There was no significant association found with the presence of PHOMS.

CONCLUSION

EDI-OCT allowed morphological analysis of ODD and PHOMS in children. Drusen were found to be distinct from PHOMS both in their appearance and impact on the RNFL. ODD are hyporeflective and appear on the ONH above the lamina cribrosa and were associated with decreased thickness of the RNFL. On the contrary, PHOMS are hyperreflective structures located around the ONH and were not associated with RNFL loss.

Optic disc drusen: a systematic review : Up-to-date and future perspective

BACKGROUND

Optic disc drusen (ODD) are acellular deposits in the prelaminar optic nerve head. The most accredited theory is that they are secondary to abnormalities in axonal metabolism and degeneration, but the pathogenesis is not clear to date.

CLINICAL MANIFESTATION

Although ODD are often considered a benign condition, the great majority of patients with ODD show visual field defects and are at higher risk for developing anterior ischemic optic neuropathy. ODD are classified as superficial or buried, with the latter being often misdiagnosed as papilledema with optic nerve head swelling, leading to an unnecessary investigation for causes of increased intracranial pressure.

AIM

The recent technological improvements in OCT imaging which allowed an earlier and more certain diagnosis even of the smallest ODD, renovated the interest around this pathology. However, an updated systematic review is still missing. Therefore, the aim of this work is to provide a concise yet comprehensive overview of the current state of art, focusing on pathophysiology, clinical presentation, diagnostic methods, treatment modalities and potential future perspectives of this condition.

Microvascular Changes Associated with Optic Disc Drusen: Case Report

Optic disc drusen (ODD) is an important clinical entity that is sometimes misdiagnosed as papilledema because of elevated and blurred disc margins. A 17-year-old male who presented with headaches underwent detailed ophthalmological examination as well as colored fundus photography, B-scan ultrasonography (USG), fundus autofluorescence (FAF), optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and visual field testing. His visual acuity was 10/10 in both eyes. Fundus examination revealed bilateral blurred and elevated optic disc margins. Diagnosis of bilateral ODD was confirmed with B-scan USG. FAF imaging revealed hyperautofluorescent areas on both optic discs. Optic nerve head OCT scans showed elevated irregular disc borders and thinning of the retinal nerve fiber layer in both eyes. On visual field testing, loss of the nasal visual field was detected in the left eye. OCTA imaging showed focal capillary dropout, especially in the nasal peripapillary area, in both eyes and reduced peripapillary and macular vessel density. In this case report, we evaluated the clinical findings and the structural features of bilateral ODD with multimodal imaging modalities including OCTA.

The optic nerve drusen and haemodynamics

PURPOSE

The optic nerve drusen (DON) are precisely described in many papers. But fewer papers evaluate real haemodynamics parameters (HP) in DON. Clinically, it has been shown, that the development and progression of visual field changes in DON is closely related to the hemodynamics of the ocular vascular supply - the optic nerve. DON can visually overlap the excavation optic disc, making it difficult to evaluate scotomas of the visual field in glaucoma.

METHODS

HP was prospectively evaluated in 54 patients with compensated intraocular pressure and DON. The drusen at the optic nerve head have been detected by fundus examination and B-scan ultrasonography (USG). DON were divided into 3 groups according to the size of the individual drusen or the drusen complex. I. Group: area size up to 1.9 mm. II. Group: area size: 1.9 - 3.9 mm. III. Group: area size: 4,0 mm. HP - maximum systolic velocity (MSV), minimal diastolic velocity (MDV) and resistance indices (IR) and index pulsatility (IP) - were recorded at the central retinal artery (CRA), at the central retinal vein (CRV), at ciliares posteriores arteries breves (CPAb) and at the ophthalmic artery (AO). The values were divided into 3 groups: 1 - Physiological: CRA: 8.7 ± 0.9 / 2.9 ± 0.6 cm/s or RI: 0.70 ± 0.05. 2 - Slightly impaired: CRA: 6.6 ± 0.8 / 2.0 ± 0.5 cm/s, or RI: 0.75 ± -0.04. 3 - Significantly impaired: CRA: 5.2 ± 1.2 / 1.9 ± 0.7 cm/sec or RI: 0.79 ± 0.03.

RESULTS

There was no linear relationship between size of DON and HP. Slight worsening of HP at the CRA was in I. Group (28.6 %), II. Group (48.3 %) and III. Group (62.4 %). Significant worsening of HP at the CRA was I. group (28.6 %), II. Group (48.3 %) and in III. Group (62.4 %). HP of the CPA and of the OA were not significant due to the presence and size of drusen. The relationship between individual variables was evaluated using the Pearson correlation coefficient 0.213. I. Group P: 0.354, II. Group P: 0.073, III. Group P: 0.287.

CONCLUSIONS

HP is more often impaired in &#8222;large&#8220; DON (Group III), rarely in Group I, but this is not a rule. HP cannot be predicted according to the size of the druse formation at the optic nerve. It seems that the deterioration of HP depends not only on the DON size but also on the location (the distance from the lamella cribriformis) and also to the vascular system intrapapillary.

Optic Nerve Head Drusen: An Update

Optic nerve head drusen are benign acellular calcium concretions that usually form early in life, just anterior to the lamina cribrosa. Improving imaging using optical coherence tomography suggests they are common and may be present in many clinically normal discs. These drusen may change in appearance in early life, but are generally stable in adulthood, and may be associated with visual field defects, anterior ischaemic optic neuropathy, or rarer complications. Based on long-term clinical data and optical coherence tomography, we propose a refined hypothesis as to the cause of optic disc drusen. Here we summarise recent findings and suggest future studies to better understand the forces involved.

Optic disc drusen: understanding an old problem from a new perspective

Optic disc drusen (ODD) are acellular deposits located in the optic nerve head of up to 2.4% of the population. They may develop as by-products of impaired axonal metabolism in genetically predisposed individuals, in whom a narrow scleral canal is hypothesized to play a role. Although ODD are often considered as benign innocent bystanders, recognized as part of a routine ophthalmological examination, the vast majority of patients with ODD have visual field defects. Optic disc drusen (ODD)-associated complications with severe visual loss, most often due to anterior ischaemic optic neuropathy, are also known to occur. There are no treatments available to prevent or ameliorate the vision loss caused by ODD. In children, the ODD are usually uncalcified and buried within the optic nerve head tissue. In these cases, the condition can be difficult to diagnose, as it often resembles a papilloedema with optic nerve head swelling caused by raised intracranial pressure. During the teenage years, the ODD progressively become more calcified and probably also larger, which allow them to be visible on ophthalmoscopy. With the advent and proper utilization of high-resolution modalities of optical coherence tomography (OCT), it has now become possible to detect even the smallest and most deeply located ODD. This allows for ODD detection at a much earlier developmental stage than has previously been possible and enhances the possibilities of research in underlying mechanisms. A review of the literature on ODD was conducted using the PUBMED database. The review focuses on the current knowledge regarding pathogenesis, diagnostics, clinical disease-tracking methodologies, structure-function relationships and treatment strategies of ODD.

Choroidal neovascularisation associated with optic nerve head drusen: Case report and review of literature

A 21-year-old man was seen for follow-up of optic nerve head drusen (ONHD) in the ophthalmology department. Funduscopy revealed the presence of choroidal neovascularisation (CNV) in the papillomacular bundle of his right eye (RE). The patient was successfully treated with two intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF). Peri-papillary choroidal neovascularisation in papillomacular bundle is a rare complication in patients with ONHD. These forms of CNV show a good response to anti-VEGF treatment.

Factors associated with visual field defects of optic disc drusen

Purpose

To investigate the prevalence and risk factors for visual field defect in patients with optic disc drusen (ODD).

Methods

We assessed the visual field status of patients with ODD whose diagnosis were confirmed by spectral-domain optical coherence tomography (SD-OCT). Visual field defects were classified as normal, enlarged blind spot, or other defects. ODD were classified into either type 1 (without hyperreflective border and heterogenic internal reflectance) or type 2 (with hyperreflective border and lower internal reflectance). The prevalence and risk factors for each visual field defect was analyzed using logistic regression analysis and classification and regression tree (CART) modeling.

Results

Of the 40 eyes with ODD, 33 (83%) eyes were categorized as type 1 and 7 (17%) eyes were categorized as type 2 ODD. Regarding the visual field defects, 19 (48%) eyes showed normal visual field, 11 (28%) eyes showed enlarged blind spot, and 9 (24%) eyes showed other defects. The latter was more frequent in type 2 ODD (P = 0.001). Logistic regression analysis revealed that the factor associated with other defects was the thinning of the average retinal nerve fiber layer (RNFL) (per 10 μm decrease, OR = 3.436, P = 0.004), and the factor associated with enlarged blind spot was the height of ODD (per 100 μm increase, OR = 3.956, P = 0.023). CART modeling revealed that the average RNFL thickness lesser than 85.5 μm, and then the ODD height larger than 348 μm were the best split-up factors for predicting the type of visual field defects.

Conclusions

In this study, one-quarter of ODD patients showed abnormal visual field defect other than enlarged blind spot. These other visual field defects appeared to be associated with the axonal loss in the eyes with type 2 ODD.

Congenital optic nerve anomalies

OBJECTIVE

To update the current knowledge about congenital optic disc anomalies.

METHODS

A comprehensive literature search was performed in the major biomedical databases.

RESULTS

Patients with these anomalies usually have poor vision in infancy. Refractive errors are common, and serous retinal detachment may develop in some of these anomalies. It is critically important to clinically differentiate between these congenital optic disc anomalies, as central nervous system malformations are common in some, whereas others may be associated with systemic anomalies.

CONCLUSIONS

Congenital optic disc anomalies are a heterogeneous group of pathologies with characteristic fundus appearance and systemic associations. We should always try to make a correct diagnosis, in order to ask for specific tests, as well as to provide an adequate follow-up.

Enhanced Depth Imaging Optical Coherence Tomography of Optic Nerve Head Drusen: A Comparison of Cases with and without Visual Field Loss

PURPOSE

Enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD OCT) has been recognized as the most sensitive tool to diagnose optic nerve head drusen (ONHD). The relationship between OCT characteristics and visual loss has not been well documented. This study compares EDI SD OCT-determined morphologic characteristics of drusen in eyes with or without visual field (VF) defects.

DESIGN

Descriptive study of patients attending the neuro-ophthalmology service of Moorfields Eye Hospital between January 2013 and October 2014.

SUBJECTS

Patients with diagnosed ONHD and EDI SD OCT imaging of the optic nerve head.

METHODS

Eyes with and without VF defects were compared with regard to retinal nerve fiber layer (RNFL) thickness, drusen morphology, size, extent, visibility on funduscopy, ultrasound, and fundus autofluorescence.

MAIN OUTCOME MEASURES

Difference in OCT characteristics of ONHD between patients with or without VF defects.

RESULTS

Of 38 patients, 69 eyes with ONHD were included. Thirty-three eyes had a normal VF with average mean deviation (MD) -0.96 (±1.2) dB and pattern standard deviation (PSD) 1.6 (±0.3) dB (group I), and 36 eyes had VF defects with MD -13.7 (±10.4) dB and PSD 7.2 (±3.6) dB (group II). Mean global RNFL thickness was 62 (±20.9) μm in the latter group and 99.0 (±12.9) μm in group I. In group I, the predominant drusen type was peripapillary drusen, of variable size. In group II, most eyes had confluent (P < 0.02) and large (>500 μm; P < 0.003) drusen, and drusen were more commonly visible on funduscopy (P = 0.001), ultrasound (P = 0.013), and autofluorescence (P = 0.002). Differences between the 2 groups reached statistical significance in a clustered analysis. RNFL thinning and autofluorescence showed relative sparing of the temporal sector. Sixty-four percent of patients with a VF defect in 1 eye also had a VF defect in their fellow eye.

CONCLUSIONS

Drusen size and drusen type as classified by OCT morphologic characteristics are significantly different in patients with or without VF defects. Confluent, large, and autofluorescent drusen were more commonly found in patients with VF defects. These findings may assist in clarifying how drusen give rise to visual loss, which is currently not known.

Optic disk drusen in children

Optic disk drusen occur in 0.4% of children and consist of acellular intracellular and extracellular deposits that often become calcified over time. They are typically buried early in life and generally become superficial, and therefore visible, later in childhood, at the average age of 12 years. Their main clinical significance lies in the ability of optic disk drusen, particularly when buried, to simulate true optic disk edema. Misdiagnosing drusen as true disk edema may lead to an invasive and unnecessary workup for elevated intracranial pressure. Ancillary testing, including ultrasonography, fluorescein angiography, fundus autofluorescence, and optical coherence tomography, may aid in the correct diagnosis of optic disk drusen. Complications of optic disk drusen in children include visual field defects, hemorrhages, choroidal neovascular membrane, nonarteritic anterior ischemic optic neuropathy, and retinal vascular occlusions. Treatment options for these complications include ocular hypotensive agents for visual field defects and intravitreal anti-vascular endothelial growth factor agents for choroidal neovascular membranes. In most cases, however, children with optic disk drusen can be managed by observation with serial examinations and visual field testing once true optic disk edema has been excluded.

The incidence of neovascular membranes and visual field defects from optic nerve head drusen in children

PURPOSE

To evaluate the incidence of visual field defects and choroidal neovascular membranes (CNVM) in a cohort of pediatric patients with optic nerve head drusen (ONHD).

METHODS

The medical records of children with ONHD seen at a single center from January 2012 to July 2014 were retrospectively reviewed to identify patients who had a dilated fundus examination, fundus photography, spectral domain optical coherence tomography (SD-OCT)/enhanced-depth imaging (EDI) of the optic nerve head (ONH), SITA fast 24-2 Humphrey visual field (HVF) testing, lumbar puncture, and ocular ultrasound. A masked neuro-ophthalmologist analyzed fundus photographs, OCT, and fields. Retinal nerve fiber layer (RNFL) data were compared to age-matched controls.

RESULTS

A total of 52 children (98 eyes) were included. Mean age was 10.8 ± 3.3 years. Of these, 42 patients had visual fields (57 eyes deemed reliable), and 19 eyes had documented visual field deficits (8 were reproducible across ≥1 sitting [frequency 14%]). After correction of plotting errors (40 eyes), RNFL thickness was 111.9 ± 17.9 μm. CNVM were present in 24 of 98 eyes (24.5%), with 21 of 24 located nasally (87.5%). Neither RNFL thinning nor identification of ONHD on fundus photography correlated with the presence of visual field defects.

CONCLUSIONS

Visual field defects due to ONHD can be reliably identified in children. In eyes of children with ONHD, RNFL protocol is frequently unreliable and may overestimate RNFL thickness. EDI scans through the ONH revealed peripapillary CNVM in nearly a quarter of the patients. Further longitudinal studies looking at the progression of CNVM and visual field deficits are warranted.

Visual Outcomes, Visual Fields, and Optical Coherence Tomography in Paediatric Craniopharyngioma

Ten patients with craniopharyngioma treated for the first time when younger than 18 were included. This study reviews the visual outcomes and provides information on visual field (VF) and optical coherence tomography (OCT) examination of craniopharyngioma. The best kappa concordance coefficients between VF and OCT parameters of atrophy were obtained for the ganglion cell (GC) thickness and the mean retinal nerve fibre layer (RNFL) thickness. The agreement between GC colour maps and VF defects was good. Optic nerve compression may be detected by RNFL measurement and GC analysis, and this may be valuable to predict visual recovery and in uncooperative patients to evaluate visual damage.

OCT: New perspectives in neuro-ophthalmology

Optical coherence tomography (OCT) has become essential to evaluate axonal/neuronal integrity, to assess disease progression in the afferent visual pathway and to predict visual recovery after surgery in compressive optic neuropathies. Besides that OCT testing is considered a powerful biomarker of neurodegeneration and a promising outcome measure for neuroprotective trials in multiple sclerosis (MS). Currently, spectral-domain OCT (SD-OCT) technology allows quantification of retinal individual layers. The Ganglion Cell layer (GCL) investigation has become one of the most useful tools from a neuro-ophthalmic perspective. It has a high correlation with perimetry, is predictive of future progression and is a highly sensitive, specific of several neuro-ophthalmic pathologies. Moreover the superior correlation with clinical measures compared to peripapillary retinal nerve fiber layer (pRNFL) suggests that GCL analysis might be a better approach to examine MS neurodegeneration. In disorders with optic disk edema, such as ischemic optic neuropathy, papillitis and papilledema, reduction in RNFL thickness caused by axonal atrophy is difficult to distinguish from a swelling resolution. In this setting, and in buried optic nerve head drusen (ONHD), GCL analysis may provide more accurate information than RNFL analysis and it might be an early structural indicator of irreversible neuronal loss. Enhanced depth imaging OCT (EDI-OCT) provides in vivo detail of ONHD, allowing to evaluate and quantify the drusen dimensions. OCT is improving our knowledge in hereditary optic neuropathies. Furthermore, there is growing evidence about the role of OCT as an adjunctive biomarker of disorders such as Alzheimer and Parkinson's disease.

Measurement of retinal nerve fiber layer and macular ganglion cell-inner plexiform layer with spectral-domain optical coherence tomography in patients with optic nerve head drusen

PURPOSE

To evaluate the effect of optic nerve head drusen (ONHD) on the retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) using Cirrus optical coherence tomography (OCT).

METHODS

Fifty-seven eyes of thirty patients with ONHD and thirty-eight eyes of twenty age-matched and sex-matched control subjects underwent circumpapillary and macular scanning using Cirrus OCT. The percentages of eyes with abnormal GCIPL and RNFL values according to the Cirrus normative data were analysed and compared.

RESULTS

Overall, eyes with ONHD showed abnormally reduced values for average and minimum GCIPL thicknesses in 35 % and 45 % of cases compared to 2 % for both values in control eyes (P < 0.001). Average RNFL thickness comparison between eyes with ONHD and normal eyes revealed abnormal thinning in 33 % vs. 0 %, respectively (p = 0.002). The percentage of abnormal thinning increased with higher grades of ONHD for all the parameters evaluated, so that in grade III drusen, values were abnormally reduced in 80 % of eyes in all three analyses. Regarding buried ONHD, 30 % and 4 % of eyes had an abnormally reduced minimum GCIPL and average RNFL thickness, respectively. Furthermore, 26 % of these eyes had abnormal GCIPL exams with a normal or increased RNFL thickness.

CONCLUSIONS

Both RNFL and GCIPL analysis reveal significant thinning in eyes with ONHD directly correlated with drusen severity. In buried ONHD, the abnormality rate was significantly higher with GCIPL compared to RNFL evaluation, suggesting that GCIPL analysis might be an early structural indicator of neuronal loss in the setting of thickened RNFL.