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

Optical coherence tomography angiography findings in optic disc drusen and idiopathic intracranial hypertension

PURPOSE

To evaluate the changes in peripapillary microvascularity in idiopathic intracranial hypertension (IIH) and optic disc drusen (ODD) patients, by comparing them with those in healthy individuals, via optical coherence tomography angiography (OCTA).

METHODS

Sixty-two eyes of 33 patients with ODD, 58 eyes of 30 patients with IIH, and 70 eyes of 70 healthy people were imaged for 6 × 6-mm optic disc scans on a spectral-domain OCTA. Vascular densities in superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) of ODD, IIH, and healthy eyes were compared with a one-way analysis of variance. Post-hoc analysis was performed with the Gabriel test.

RESULTS

There was a significant decrease in peripapillary vessel density in SCP, DCP, and CC in patients with IIH compared to the control group (p < 0.05). In ODD patients, especially peripapillary vessel density in DCP was significantly reduced compared to the control group (p < 0.05). Peripapillary vessel density in DCP was significantly lower in the IIH group than ODD group (p < 0.05).

CONCLUSIONS

Peripapillary vascular density may be affected during the course of the disease in both IIH and ODD. Compared to healthy individuals, the decrease in vascular density in these patients and the consequent decrease in perfusion in the peripapillary region may guide the pathogenesis of the complications in the course of these two diseases. Although vascular density in DCP and CC differs significantly between IIH and ODD, case-controlled studies are needed to evaluate the role of OCTA in the differential diagnosis of IHH and ODD.

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 Presence of Optic Disc Drusen in Eyes with Uveitis

PURPOSE

To evaluate the coexistence of optic disc drusen (ODD) in eyes with uveitis.

METHODS

In this retrospective, observational study, patients followed up in a uvea clinic with all types of uveitis were evaluated. ODD were confirmed by ocular ultrasonography, optic nerve head enhanced-depth imaging optical coherence tomography, fundus autofluorescence, and fundus photography.

RESULTS

ODD were detected in 17 of 545 (3.1%) uveitis patients. The mean age was 18.9 ± 10.4 years, and 76.5% were female. 45.5% were anterior, 42.4% were panuveitis, 6.1% were intermediate, and 6.1% were posterior uveitis. ODD were found bilaterally in all 17 patients; uveitis was unilateral in one patient. 58.8% were under the age of 18, and in this group, the rate of buried ODD was 78.9% (p = 0.039). In adults (seven patients), ODD were buried in 42.9%.

CONCLUSION

ODD can be detected in eyes with uveitis and may clinically mimic optic disc edema, lead to misdiagnosis and/or overtreatment.

Morpho-Functional Assessment of Retinal Ganglion Cells and Visual Pathways in Patients with Optic Disc Drusen: Superficial Drusen Visible Height as a Marker of Impairment

The aim of this study was to assess the morpho-functional involvement of the retinal ganglion cells (RGCs) and of the visual pathways in patients with superficial (ODD-S) or deep (ODD-D) optic disc drusen. This study enrolled 17 patients with ODD (mean age of 59.10 ± 12.68 years) providing 19 eyes and 20 control subjects (mean age 58.62 ± 8.77 years) providing 20 eyes. We evaluated the following: best-corrected visual acuity, visual field mean deviation (MD), the amplitude (A) of Pattern Electroretinogram (PERG), the implicit time (IT) and A of Visual Evoked Potentials (VEPs), retinal nerve fiber layer thickness (RNFL-T) and ganglion cell thickness (GC-T). In ODD-S eyes, the drusen visible height was measured. ODD-D and ODD-S were detected in 26.3% and 73.7% of ODD eyes, respectively. Significantly (p < 0.01) reduced MD, PERG A, VEP amplitude, RNFL-T and GC-T values and significantly (p < 0.01) increased VEP IT values were found in the ODD Group as compared to the Control one. In the ODD Group, no significant correlation (p > 0.01) between PERG As and VEP ITs was found. In ODD-S, the visible height was significantly correlated (p < 0.01) with reduced MD, PERG As and RNFL-T and with increased PSD and VEP IT values. Our findings suggest that ODD might induce morpho-functional changes in RGCs and their fibers and an unrelated visual pathway dysfunction leading or not leading to visual field defects. The observed morpho-functional impairment should be ascribed to an alteration in retrograde (from the axons to the RGCs) and anterograde (from the RGCs up to the visual cortex) axoplasmic transport. In ODD-S eyes, a minimum visible height of 300 microns represented the threshold for the abnormalities, suggesting that "the higher the ODD, the worse the impairment".

Optic nerve sheath diameter and axial length in patients with optic disc drusen: a cross-sectional study

AIM

Measuring the optic nerve sheath diameter (ONSD) and the anteroposterior axial length of the eye in patients with optic disc drusen (ODD).

METHODS

A total of 43 healthy volunteers and 41 patients with ODD were included in the study. The ONSD and axial length were measured in the posterior position using an ultrasound device (E-Z Scan AB5500 +) probe with a 10 MHz frequency. The ONSD was measured 3 mm behind the globe wall. Receiver operating characteristic (ROC) curve analysis was performed to determine patients with ODD using ONSD. Any p-value of < 0.05 was accepted to demonstrate significance.

RESULTS

The ONSD was significantly higher (5.2 mm and 4.8 mm, p = 0.006, respectively), and the axial length was shorter (21.82 ± 2.15 mm and 23.27 ± 1.96 mm, p = 0.002, respectively) in the ODD group. The spherical equivalent was more commonly seen as hypermetropic in the ODD group (1.00 [- 0.85 to 1.75]). In the ROC analysis to determine the ONSD value in ODD diagnosis, the area under the curve was 0.6754 (95% confidence interval 0.559-0.788, p = 0.006). ONSD cutoff of 5.70 mm had a sensitivity of 0.366 and a specificity of 0.907 to diagnose ODD.

CONCLUSION

In this study, the ONSD was significantly higher in the ODD group. The axial length was shorter in the ODD group. This study is the first in the literature to evaluate the ONSD in patients with optic disc drusen. Further studies are needed in this regard.

Bilateral Progressive Optic Neuropathy in a Patient with Familial Amyloid Polyneuropathy: Amyloid Deposits in the Optic Nerve Head?

Familial amyloid polyneuropathy is a rare autosomal dominant hereditary disease. Optic nerve involvement is frequently observed secondary to uncontrolled glaucoma but, rarely, an ischaemic optic neuropathy can occur. In this case report we describe a patient who presented with bilateral progressive visual loss and constriction of his visual fields. Fundus examination showed intense paleness of both optic discs with elevated, poorly defined margins that seemed to be infiltrated. Fundus autofluorescence and enhanced-depth imaging optical coherence tomography ruled out the presence of optic disc drusen. Orbital magnetic resonance imaging ruled out any sign of orbital compression, inflammation or infiltration of the optic nerve. The mechanism of small vessel amyloid infiltration and a possible vessel compression by amyloid in the optic nerve head is discussed.

Optic Nerve Drusen Evaluation: A Comparison between Ultrasound and OCT

This observational study compared optic coherence tomography (OCT) and B-scan in the detection of optic disc drusen. In total, 86 eyes of 50 patients with optic disc drusen (ODD) (36 bilateral) with a mean age of 34.68 ± 23.81 years, and 54 eyes of 27 patients with papilledema, with a mean age of 35.42 years ± 17.47, were examined. Patients with ODD, diagnosed with ultrasound, underwent spectral-domain OCT evaluation. With US, 28 ODD cases were classified as large (4 buried and 24 superficial), 58 were classified as point-like (6 buried, 49 superficial and 3 mixed). Then, all patients underwent OCT. OCT was able to detect the presence of ODD and/or peripapillary hyperreflective ovoid mass structure (PHOMS) in 69 eyes (p < 0.001). In particular, 7 eyes (8.14%) showed the presence of ODD alone, 25 eyes (29.07%) showed only PHOMS and 37 eyes (43.02%) showed ODD and PHOMS. In 17 eyes (19.77%) no ODD or PHOMS were detected. In the papilledema group, no ODD were observed with both US and OCT. OCT showed the presence of drusen or similar lesions in only 80.23% of the cases highlighted by the US scan, so it does not allow for certain ODD diagnoses, especially in the case of buried ODD.

Volumetric Measurement of Peripapillary Hyperreflective Ovoid Masslike Structures in Patients with Optic Disc Drusen

Purpose

To develop a method to determine the volume of peripapillary hyperreflective ovoid masslike structures (PHOMS) and to examine the correlation between PHOMS and anatomic optic nerve head characteristics in a large cohort of patients with optic disc drusen (ODD).

Design

Retrospective, observational study of patients with ODD.

Participants

Patients with ODD seen in a 3-year period.

Methods

We determined the prevalence of PHOMS. We then developed a method to calculate the volume of PHOMS and measured this in all patients where radial scans on OCT were available. We analyzed the correlation between PHOMS volume and patient age, size of Bruch's membrane opening (BMO), ODD visibility, and anatomic location of ODD in the optic nerve.

Main Outcome Measures

Prevalence and characteristics of PHOMS in patients with ODD.

Results

In 247 (77%) eyes with ODD, PHOMS were found. Among these, 80% were in the first decade of life, 87% were in the second decade, 89% were in the third decade, 85% were in the fourth decade, 74% were in the fifth decade, 73% were in the sixth decade, 58% were in the seventh decade, 40% were in the eighth decade, and 0% were in the ninth decade. The ophthalmoscopic visibility of ODD increased with age. The volume of PHOMS decreased with age, but with no correlation to the size of BMO. The median volume of PHOMS was 0.27 mm3 (interquartile range [IQR], 0.13-0.49 mm3). Predominantly, PHOMS were observed in the nasal peripapillary area (87.5% nasal, 78.5% superior, 67% inferior, and 63.5% temporal).

Conclusions

In patients with ODD, PHOMS are seen frequently, with the highest prevalence in younger individuals. The volume of PHOMS decreases with age, and PHOMS are seen more frequently in patients with superficial ODD.

Coexistence of idiopathic intracranial hypertension and optic disc drusen in a latin american patient: case report

Optic nerve drusen are acellular concretions of calcium located in the parenchyma of the optical nerve head described as the most common cause of pseudo-papilloedema, which makes it difficult to differentiate from a true optical disc oedema. Despite it being rare, the drusen of the optic nerve and the papilloedema secondary to idiopathic intracranial hypertension can coexist in the same patient. The case is presented of a 34 year-old woman referred to the Ophthalmology Department with visual discomfort, headaches, and pulsatile tinnitus of two months onset. In the physical examination there was bilateral blurring of the optic disc margin with absence of spontaneous venous pulsation. The diagnosis of idiopathic intracranial hypertension was made by lumbar puncture with the measurement of the opening pressure, and due to the findings of the magnetic resonance scan of the brain and the eye sockets. The optic nerve drusen was an incidental finding in an optical coherence tomography angiography, which would later be confirmed with an eye ultrasound. To our knowledge, this the first case reported in Latin America of the coexistence of optic nerve drusen and papilloedema secondary to idiopathic intracranial hypertension.