Drusen of the optic disc

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.

Peripapillary hyperreflective ovoid mass-like structures: Multimodal imaging-A review

Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are a laterally bulging herniation of distended axons into the peripapillary region above the level of Bruch's membrane opening. Increased use of enhanced depth imaging-optical coherence tomography (EDI-OCT) in our evaluation of the optic nerve head (ONH) and greater recognition of the vast range of optic nerve pathologies with which PHOMS is associated provides convincing evidence that PHOMS is not just buried optic disc drusen (ODD) as previously described. The frequent coexistence of PHOMS with ODD, papilloedema, anterior ischaemic optic neuropathy, tilted optic disc syndrome, inflammatory demyelinating disorders and other diseases associated with axoplasmic stasis provides insight into its underlying pathophysiology. The present review will discuss the role of key imaging modalities in the differential diagnosis of PHOMS, explore the current literature on the relationship between PHOMS and common neuro-ophthalmic conditions, and highlight the gaps in our knowledge, with respect to disease classification and prognosis, to pave the way for future directions of research.

Optic Disc Drusen (ODD), an Often Misdiagnosed Disease: A Case Report

Optic disc drusen (ODD) are abnormal collections of protein and calcium that accumulate within the optic nerve. We report a case of a 17-year-old girl who presented to the Department of Ophthalmology at the Cheikh Khalifa International University Hospital, Casablanca, Morocco, with a decline in visual acuity, visual field deficiency, and color vision abnormalities. The patient was misdiagnosed and mistreated for optic neuritis given the presence of bilateral Stage III papilledema solely. After many months of diagnostic wandering, a fundus examination revealed a white atrophic papilla with calcified deposits grouped in a crown around the papillary excavation, suggesting papillary drusen. When the deposits are visible on ophthalmoscopy and manifest as an elevation and a blurring of the optic disc's margins, their diagnosis remains straightforward. However, their identification might be problematic when they are firmly lodged in the optic disc or with the presence of papilledema, leading to confusion with other differential diagnoses, particularly if the condition affects both eyes. The purpose of this case report is to increase neurologists' and ophthalmologists' knowledge of the incidence of drusen in order to prevent excessive biological and imaging investigation in addition to harmful effects from needless drugs.

The status of the choroid in patients with optic disc drusen

PURPOSE

To investigate the subfoveal and peripapillary choroidal thickness (CT) and the choroidal vascularity index (CVI) in patients with optic disc drusen (ODD).

METHODS

This cross-sectional study examined the eyes of 17 patients with ODD and 18 healthy control subjects. The CT values were calculated manually from the images captured by enhanced depth imaging-optical coherence tomography (EDI-OCT). The CVI was defined as the proportion of the vascular area to the total choroidal area at the subfoveal and peripapillary areas after binarization of the EDI-OCT images.

RESULTS

It was found that the mean subfoveal CVI value in the ODD group was significantly lower than that in the control group (p = 0.006). The mean peripapillary CVI values were significantly lower in all of the quadrants in the ODD group when compared with the control group (p = 0.008 for the temporal quadrant, p = 0.014 for the nasal quadrant, p = 0.024 for the superior quadrant, and p = 0.038 for the inferior quadrant). Regarding the CT, there were no significant differences in the subfoveal and peripapillary CT values between the ODD group and the control group (p >  0.05 for all values).

CONCLUSION

The findings of this study indicate ODD to be associated with decreased subfoveal and peripapillary CVI, even though the subfoveal and peripapillary CT values were within the normal range. This result may prove important in relation to identifying a choroidal vascular network that appears to be morphologically normal but microstructurally impaired due to ODD. Further studies are required to verify the significance of CVI in the pathogenesis and complications of ODD.

Detection of superficial and buried optic disc drusen with swept-source optical coherence tomography

Background

To detect the superficial and buried optic disc drusen (ODD) with swept-source optical coherence tomography (SS-OCT).

Methods

Retrospective cross-sectional study. Twenty patients (age 18–74 years) diagnosed with ODD via B-scan ultrasonography were analysed. All patients underwent color fundus photography (CFP), B-scan ultrasonography, fundus autofluorescence (FAF), and SS-OCT. We defined each hyporeflective signal mass of SS-OCT as an ODD, recorded its location and relationship with Bruch’s membrane opening (BMO), and other ophthalmic imaging characteristics.

Results

Twenty (33 eyes) patients had 54 ODDs in all, except one eye did not show abnormal optic disc findings on SS-OCT. We classified ODD into three categories: ODD above BMO, ODD across BMO, and ODD below BMO. The ODDs across BMO were the largest, followed by ODDs below BMO, and those above BMO. The location of the ODDs: One (1.9%) was in the border tissue of Elschnig, 6 (11.1%) might span across the lamina cribrosa, 16 (29.6%) were above BMO located in the neuroepithelial layer, 9 (16.7%) spanned across BMO located near the center of the optic disc, 18 (33.3%) were below BMO located near the center of the optic disc, 4 (7.4%) were below BMO located within the optic disc rim. When the anterior margin was ≥ 100 μm from the BMO, clear autofluorescence could be seen.

Conclusion

Multimodal imaging provided a deeper understanding of ODD. SS-OCT illustrated more details about the relationship between the posterior surface of ODD, BMO and the lamina cribrosa.

Clinical and Multi-Mode Imaging Features of Eyes With Peripapillary Hyperreflective Ovoid Mass-Like Structures

Purpose

To observe and analyze the clinical and multi-mode imaging features of eyes with PHOMS, and to introduce two cases of PHOMS which underwent multi-mode imaging.

Methods

Retrospective clinical observational study. A total of 26 patients (37 eyes) with hyperreflective structures surrounded by hyporeflective edges around the optic discs who were examined and diagnosed at Shandong Eye Hospital between January 2019 and June 2021 were included in the study. Among these patients, 12 were male and 14 were female. Fifteen were monocular. The average age was 39 years. All patients underwent the following examinations: Best-corrected visual acuity (BCVA), intraocular pressure examinations, slit-lamp anterior segment examinations, indirect ophthalmoscopy, visual field examinations, fundus color photography, fundus autofluorescence (FAF), optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA). Some of the patients were examined with fundus fluorescein angiography (FFA). Clinical data and imaging characteristics from the OCT, OCTA, and FFA were analyzed retrospectively.

Results

We found the hyperreflective structures surrounded by hyporeflective edges around the optic discs in 37 eyes. EDI-OCT results revealed hyperreflective structures surrounded by hyporeflective edges around the optic discs in all eyes. Typical hyperreflexia lesions occurred around the optic disc, located subretinally and above Bruch's membrane. OCTA revealed that the highly reflective perioptic material also had vascular structures.

Conclusion

EDI-OCT of PHOMS showed hyperreflective structures surrounded by hyporeflective edges around all of the optic discs. Infra-red photography showed temporal hyperreflexia. These characteristics can be seen in a variety of diseases and may be a relatively common feature revealed by EDI-OCT scanning. These characteristics may also be seen in elderly patients as well as children. PHOMS may be found in optic disc drusen (ODD), tilted disc syndrome (TDS), optic neuritis, ischemic optic neuropathy, and in white dot syndromes. Few patients may be developed into macular neovascularization (MNV). In order to improve the accuracy and robustness of the conclusions and provide better clinical guidance, we need to conduct more comprehensive research in the subsequent clinical work.

Peripapillary Hyper-reflective Ovoid Mass-like Structure (PHOMS): An Optical Coherence Tomography Marker of Axoplasmic Stasis in the Optic Nerve Head

BACKGROUND

With the development and widespread adoption of spectral-domain optical coherence tomography (OCT), peripapillary hyper-reflective ovoid mass-like structures (PHOMS) have become a frequent OCT finding in neuro-ophthalmic practice. Although originally assumed to represent a form of buried optic disc drusen (ODD), PHOMS differ from ODD in many important ways. The histopathological underpinnings of PHOMS are now becoming more clearly understood.

EVIDENCE ACQUISITION

Review of literature.

RESULTS

PHOMS can be broadly classified as disk edema-associated PHOMS, ODD-associated PHOMS, or anomalous disk-associated PHOMS. PHOMS are seen in many conditions, including papilledema, nonarteritic anterior ischemic optic neuropathy, central retinal vein occlusion, acute demyelinating optic neuritis, ODD, and tilted disks (myopic obliquely inserted disks) and in many cases resolve along with the underlying condition. The histopathological study of these diverse entities reveals the common feature of a bulge of optic nerve fibers herniating centrifugally over Bruch membrane opening into the peripapillary space, correlating exactly with the location, shape, and space-occupying nature of PHOMS on OCT. Because of the radial symmetry of these herniating optic nerve fibers, PHOMS are best thought of as a complete or partial torus (i.e., donut) in 3 dimensions.

CONCLUSIONS

PHOMS are a common but nonspecific OCT marker of axoplasmic stasis in the optic nerve head. They are not themselves ODD or ODD precursors, although they can be seen in association with ODD and a wide spectrum of other conditions. They do not exclude papilledema and often accompany it. The circumferential extent and characteristic 3D toroidal nature of a PHOMS are best appreciated by scrolling through consecutive OCT images.

Oxidative Stress in Optic Neuropathies

Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber's hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable results. Understanding the role of oxidative stress in optic neuropathies can serve to develop therapeutic strategies directed at the redox system to arrest the neurodegenerative processes in the retina and RGCs and ultimately prevent vision loss.

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.

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.

Clinical application of ultra-widefield fundus autofluorescence

PURPOSE

To review the basic principles of ultra-widefield fundus autofluorescence (UWF-FAF) and discuss its clinical application for a variety of retinal and choroidal disorders.

METHODS

A systematic review of the PubMed database was performed using the search terms "ultra-widefield," "autofluorescence," "retinal disease" and "choroidal disease."

RESULTS

UWF-FAF imaging is a recently developed noninvasive retinal imaging modality with a wide imaging range that can locate peripheral fundus lesions that traditional fundus autofluorescence cannot. Multiple commercially available ultra-widefield imaging systems, including Heidelberg Spectralis and Optomap Ultra-Widefield systems, are available to the clinician. Imaging by UWF-FAF is more comprehensive; it can reflect the content and distribution of the predominant ocular fluorophore in retinal pigment epithelial cells and evaluate the metabolic status of RPE of various retinal and choroidal disorders.

CONCLUSION

UWF-FAF can detect abnormalities that traditional fundus autofluorescence cannot; therefore, it can be used to better elucidate disease pathogenesis, analyze genotype-phenotype correlations, diagnose and monitor disease.

An in vitro model of chronic wounding and its implication for age-related macular degeneration

Degeneration of the retinal pigment epithelium (RPE) plays a central role in age-related macular degeneration (AMD). Throughout life, RPE cells are challenged by a variety of cytotoxic stressors, some of which are cumulative with age and may ultimately contribute to drusen and lipofuscin accumulation. Stressors such as these continually damage RPE cells resulting in a state of chronic wounding. Current cell-based platforms that model a state of chronic RPE cell wounding are limited, and the RPE cellular response is not entirely understood. Here, we used the electric cell-substrate impedance sensing (ECIS) system to induce a state of acute or chronic wounding on differentiated human fetal RPE cells to analyze changes in the wound repair response. RPE cells surrounding the lesioned area employ both cell migration and proliferation to repair wounds but fail to reestablish their original cell morphology or density after repetitive wounding. Chronically wounded RPE cells develop phenotypic AMD characteristics such as loss of cuboidal morphology, enlarged size, and multinucleation. Transcriptomic analysis suggests a systemic misregulation of RPE cell functions in bystander cells, which are not directly adjacent to the wound. Genes associated with the major RPE cell functions (LRAT, MITF, RDH11) significantly downregulate after wounding, in addition to differential expression of genes associated with the cell cycle (CDK1, CDC6, CDC20), inflammation (IL-18, CCL2), and apoptosis (FAS). Interestingly, repetitive wounding resulted in prolonged misregulation of genes, including FAS, LRAT, and PEDF. The use of ECIS to induce wounding resulted in an over-representation of AMD-associated genes among those dysregulated genes, particularly genes associated with advanced AMD. This simple system provides a new model for further investigation of RPE cell wound response in AMD pathogenesis.

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.

Association between myopia and peripapillary hyperreflective ovoid mass-like structures in children

We investigated the characteristics of children with peripapillary hyperreflective ovoid mass-like structures (PHOMS) and evaluated the associated risk factors. This cross-sectional study included 132 eyes of 66 children with PHOMS and 92 eyes of 46 children without PHOMS (controls) who were assessed by disc enhanced-depth image spectral-domain (SD) optical coherence tomography (OCT). Univariable and multivariable logistic analyses were performed to evaluate risk factors associated with presence of PHOMS. Among the 66 children with PHOMS, 53 (80.3%) had bilateral and 13 (19.7%) had unilateral PHOMS. The mean age of the PHOMS group was 11.7 ± 2.6 years, and that of the control group was 11.4 ± 3.1 years. The mean spherical equivalent (SE) as determined by cycloplegic refraction was −3.13 ± 1.87 diopters (D) in the PHOMS group and −0.95 ± 2.65 D in the control group. Additionally, mean astigmatism was 0.67 ± 0.89 D and 0.88 ± 1.02 D in the PHOMS group and the control group, respectively. Mean disc size was 1,735 ± 153 µm in the PHOMS group and 1,741 ± 190 µm in the control group, while mean optic nerve head (ONH) tilt angle was 9.84 ± 5.38 degrees in the PHOMS group and 3.71 ± 4.41 degrees in the control group. SE and ONH tilt angle were significantly associated with PHOMS according to both univariable [odds ratio (OR): 1.59; p < 0.001 and OR: 1.35; p < 0.001, respectively] and multivariable (OR: 1.71; p = 0.001 and OR: 1.29; p = 0.001, respectively) logistic regression analyses. There was a significant correlation between SE and ONH tilt (r = −0.46; p < 0.001). In conclusion, PHOMS is associated with myopic shift in children, and optic disc tilt may be a mediator between myopia and PHOMS.

OCT angiography in optic disc drusen: comparison with structural and functional parameters

BACKGROUND

Optic disc drusen (ODD) can cause retinal nerve fibre layer (RNFL) defects with progressive visual field (VF) loss. Microvascular changes are discussed as a cause. We measured the vessel density (VD) of the optic disc in ODD using optical coherence tomography angiography and compared it with a normal population. Another intent was to determine the sensitivity and correlations in comparison with functional (VF) and structural parameters (RNFL, minimum rim width (MRW), ganglion cell complex (GCC)).

METHODS

We analysed the VD of 25 patients with ODD and an age-matched control population including 25 healthy participants using AngioVue (Optovue, Fremont, CA, USA). We obtained data about RNFL, GCC, Bruch's membrane opening MRW (Spectralis HRA & OCT; Heidelberg Engineering, Germany) and VF (standard automated perimetry; SITA 24-2). Low image quality and pathologies interfering with the diagnostics were excluded. Parametric data were analysed using the t-test and non-parametric values using the Mann-Whitney U test. Linear regression analysis was used to determine correlations using the Bravais-Pearson test.

RESULTS

The VD was significantly reduced in the ODD group especially the peripapillary capillary VD (n=45 vs 50 eyes; mean 43.15% vs 51.70%). Peripapillary RNFL thickness correlated with the VD significantly (r=0.902 (n=44), 0.901 (n=44), 0.866 (n=45)). The RNFL analysis showed a reduction in ODD, especially the superior hemisphere (mean 107 µm, 129 µm; 49 vs 50 eyes). The GCC was significantly lower in the ODD group (n=38 vs 40; mean 87 µm vs 98 µm). Positive correlation between the VD and the GCC was significant (n=37, r=0.532). There is a significant negative correlation (n=19; r=-0.726) between the VD and the pattern standard deviation (PSD).

CONCLUSION

This study reveals significant peripapillary microvascular changes in patients with ODD correlating with the RNFL and GCC reduction. There is a negative correlation between the PSD and the VD.

A study of optic nerve head drusen in 38 pseudoxanthoma elasticum (PXE) patients (64 eyes). Location of optic nerve head drusen in PXE

PURPOSE

To investigate the prevalence and location of optic nerve head drusen and their potential association with other PXE-related ophthalmic abnormalities.

MATERIALS AND METHODS

Thirty-eight of the 155 patients (57 male and 98 female aged 49±17 years) included in this retrospective study had optic nerve head drusen. All of the patients underwent a comprehensive ophthalmic examination, including color images using red-free, blue and red filters, autofluorescence imaging and late-phase ICG frames. Comparative analysis of both groups (optic nerve head drusen or not) was conducted using R statistical software.

RESULTS

The prevalence of optic nerve head drusen in our cohort was 24.5%. In this study, no evidence of a significant link between optic nerve head drusen and other fundus abnormalities was detected. They were more commonly located in the nasal sector than in the temporal sector of the optic disc (P<0.001). They were more frequently situated superonasally than inferonasally (P<0.004), superotemporally (P<0.001) or inferotemporally (P<0.03). No central visual field defect was observed in OND+ patients who were unaffected by macular disorders.

DISCUSSION

We hypothesized this predominantly nasal primary location may result from greater sensitivity in the nasal optic nerve fibers which follow a much more angular path once they arrive in the scleral canal, accounting for accumulation of axoplasmic debris.

CONCLUSION

In PXE, optic nerve head drusen are mostly located in the superonasal quadrant, causing progressive optic nerve invasion but probably no central visual field defects.

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.

Cataract and optic disk drusen in a patient with glycogenosis and di George syndrome: clinical and molecular report

Background

We report the ophthalmic findings of a patient with type Ia glycogen storage disease (GSD Ia), DiGeorge syndrome (DGS), cataract and optic nerve head drusen (ONHD).

Case presentation

A 26-year-old white woman, born at term by natural delivery presented with a post-natal diagnosis of GSD Ia. Genetic testing by array-comparative genomic hybridization (CGH) for DGS was required because of her low levels of serum calcium. The patient has been followed from birth, attending the day-hospital every six months at the San Paolo Hospital, Milan, outpatient clinic for metabolic diseases and previously at another eye center. During the last day-hospital visit, a complete eye examination showed ONHD and cataract in both eyes. Next Generation Sequencing (NGS) was subsequently done to check for any association between the eye problems and metabolic aspects.

Conclusions

This is the first description of ocular changes in a patient with GSD Ia and DGS. Mutations explaining GSD Ia and DGS were found but no specific causative mutation for cataract and ONHD. The metabolic etiology of her lens changes is known, whereas the pathogenesis of ONHD is not clear. Although the presence of cataract and ONHD could be a coincidence; the case reported could suggest that hypocalcemia due to DGS could be the common biochemical pathway.

Optic Nerve Head Drusen Prevalence and Associated Factors in Clinically Normal Subjects Measured Using Optical Coherence Tomography

OBJECTIVE

To investigate the prevalence of optic nerve head drusen (ONHD) in clinically normal subjects using enhanced depth imaging (EDI) optical coherence tomography (OCT) and to evaluate associated factors.

DESIGN

Prospective, cross-sectional, observational study.

PARTICIPANTS

Total of 130 clinically normal subjects.

METHODS

Serial horizontal and vertical EDI OCT B-scans (interval between scans, ∼30 μm) of the optic nerve head (ONH) were obtained in both eyes of clinically normal subjects. Signs of ONHD were defined as horizontal hyperreflective bands perpendicular to the OCT beam with or without a signal-poor core. The minimum length of isolated hyperreflective bands was determined based on analysis of 34 eyes with clinically definite ONHD. Age, gender, ONH diameter, and axial length were obtained from participants.

MAIN OUTCOME MEASURES

Prevalence of ONHD in clinically normal subjects and its association with age, gender, ONH diameter, and axial length.

RESULTS

Based on the measurements of 94 isolated hyperreflective bands in the 34 eyes with clinically definite ONHD, the minimum length of isolated hyperreflective ONHD bands in clinically normal subjects was set as 45 μm (mean minus 2 standard deviations). Among 260 clinically normal eyes (130 subjects; 68 women; mean age, 40±17 years), EDI OCT was positive for horizontal hyperreflective ONHD bands in 28 eyes (10.8%) of 19 subjects (14.6%). Of these 28 eyes, 25 eyes (9.6% of total 260 eyes) of 16 subjects (12.3% of total 130 subjects) showed isolated hyperreflective bands with no signal-poor core, and 3 eyes (1.2% of total 260 eyes) of 3 subjects (2.3% of total 130 subjects) showed a signal-poor core surrounded by hyperreflective bands. No significant differences were found in mean age (44 vs. 39 years; P = 0.121) or gender distribution (56% vs. 52% female; P = 0.766) between clinically normal subjects with hyperreflective ONHD bands and those without. Logistic regression analysis showed that a decrease in ONH diameter by 100 μm and axial length by 1 mm increased the odds of ONHD presence by 1.5-fold (odds ratio [OR] = 1.56 [confidence interval (CI), 1.22-2.00]; P < 0.001) and 2-fold (OR = 2.00 [CI, 1.15-3.49]; P = 0.015), respectively.

CONCLUSIONS

Subclinical ONHD may be more prevalent than previously believed. Significant associations of subclinical ONHD with smaller ONH and shorter axial length were found.

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.

Optic Disc Drusen: Longitudinal Aspects, with Emphasis on Visual Field Constriction and Enlarged Blind Spot: A Retrospective Hospital-Based Clinical Series

Purpose

To examine long-term data on optic disc drusen (ODD) from an outpatient hospital series that indicated more cases with advanced visual field constriction than is apparent from other clinical reports. The underlying pathophysiology is discussed, also with regard to enlarged blind spot, which, in view of the small disc at risk, may seem a paradox.

Methods

This is an observational retrospective study on an eye clinic series (n = 49), focusing on visual acuity, kinetic/static perimetry, and longitudinal trends, to include the question of eventual visual incapacity.

Results

Forty-nine patients (32 female and 17 male; bilateral ODD in 45) aged 5-76 years (median age 29 years for both sexes) were included in the study. Observation time was 1-54 years, with serial data recorded over at least 3 years in 25 patients. Visual field defects were found in 32 patients, with ODD considered responsible for the visual field defects demonstrated. Advanced unilateral concentric constriction (for the largest Goldmann object) was recorded in 10 patients, and bilaterally in 2. With regard to nonexplanatory side diagnoses, 2 patients had pituitary adenoma, 1 had a cavernous sinus meningioma, and 1 had neurosurgery for an arachnoid cyst.

Conclusions

We found more cases of marked visual field constriction than reported in other clinical series. A few such cases appeared acute and vascular, but the main trend was clinically quiet over time. All 49 patients could manage visually in daily life.

β-Thalassemia and ocular implications: a systematic review

Background

Beta-thalassemia is a severe genetic blood disorder caused by a mutation in the gene encoding for the beta chains of hemoglobin. Individuals with beta-thalassemia major require regular lifelong Red Blood Cell transfusions to survive. Ocular involvement is quite common and may have serious implications.

Methods

Extensive review of observational studies on beta-thalassemia, to determine the prevalence and spectrum of ocular abnormalities, by clinical examination and multimodal imaging, and to investigate risk factors for their development.

Results

Frequency of ocular involvement differs among various studies (41.3–85 %, three studies). Ocular findings in beta-thalassemia may correlate to the disease itself, iron overload or the chelating agents used. Beta-thalassemia ocular manifestations include ocular surface disease, as demonstrated by tear function parameters (two studies). Lens opacities are present in 9.3–44 % (five studies). Lenticular opacities and RPE degeneration correlated positively with use of desferrioxamine and deferriprone respectively (two studies). Ocular fundus abnormalities characteristic of pseudoxanthoma elasticum (PXE), including peau d’orange, angioid streaks, pattern dystrophy-like changes, and optic disc drusen are a consistent finding in seven studies. Patients with PXE-like fundus changes were older than patients without these fundus changes (two studies). Age (two studies) and splenectomy (one study) had the strongest association with presence of PXE-like fundus changes. Increased retinal vascular tortuosity independently of the PXE-like fundus changes was found in 11–17.9 % (three studies), which was associated with aspartate amino transferase, hemoglobin and ferritin levels (two studies). Fundus autofluorescence and electrophysiological testing (ERG and EOG) may indicate initial stages or more widespread injury than is suggested by fundus examination (two studies).

Conclusions

Beta-thalassemia may present with various signs, both structural and functional. Pseudoxanthoma elasticum like fundus changes are a frequent finding in patients with b-thalassemia. These changes increase with duration or severity of the disease. Retinal vascular tortuosity may be an additional disease manifestation related to the severity and duration of anemia and independent of the PXE-like syndrome. Patients with long-standing disease need regular ophthalmic checkups because they are at risk of developing PXE-like fundus changes and potentially of subsequent choroidal neovascularization.

The cost-effectiveness of different strategies to evaluate optic disk drusen in children

PURPOSE

To compare the costs of diagnostic work-up for optic disk drusen where ophthalmic ultrasound was performed prior to imaging and invasive studies with those where ophthalmic ultrasound was performed after such studies.

METHODS

The medical records of patients <18 years of age evaluated at a tertiary referral center between 2007 and 2012 for "swollen" optic nerves were retrospectively reviewed. The main outcome measure was cost of diagnostic work-up according to Georgia Medicaid global reimbursement rates.

RESULTS

A total of 46 children with a B-scan ultrasound-confirmed diagnosis of calcified optic disk drusen were included. Neuroimaging was performed in 23 patients, of whom 20 had the study prior to ophthalmic ultrasound. The mean cost of evaluations for patients undergoing ancillary testing prior to ophthalmic ultrasound was $1,173; for those undergoing ancillary testing after, $305.

CONCLUSIONS

Because optic disk drusen can mimic the appearance of papilledema, it is more cost-effective to perform ophthalmic ultrasonography prior to neuroimaging, especially when the patient is asymptomatic. If ophthalmic ultrasonography confirms the presence of drusen, it is more cost-effective to reassess the clinical picture before proceeding with further tests.

Assessment of optic nerve head drusen using enhanced depth imaging and swept source optical coherence tomography

BACKGROUND

Optic nerve head drusen (ONHD) are calcific deposits buried or at the surface of the optic disc. Although ONHD may be associated with progressive visual field defects, the mechanism of drusen-related field loss is poorly understood. Methods for detecting and imaging disc drusen include B-scan ultrasonography, fundus autofluorescence, and optical coherence tomography (OCT). These modalities are useful for drusen detection but are limited by low resolution or poor penetration of deep structures. This review was designed to assess the potential role of new OCT technologies in imaging ONHD.

EVIDENCE ACQUISITION

Critical appraisal of published literature and comparison of new imaging devices to established technology.

RESULTS

The new imaging modalities of enhanced depth imaging optical coherence tomography (EDI-OCT) and swept source optical coherence tomography (SS-OCT) are able to provide unprecedented in vivo detail of ONHD. Using these devices it is now possible to quantify optic disc drusen dimensions and assess integrity of neighboring retinal structures, including the retinal nerve fiber layer.

CONCLUSIONS

EDI-OCT and SS-OCT have the potential to allow better detection of longitudinal changes in drusen and neural retina and improve our understanding of drusen-related visual field loss.

The spectrum of ocular alterations in patients with β-thalassemia syndromes suggests a pathology similar to pseudoxanthoma elasticum

PURPOSE

To determine the prevalence and spectrum of ocular fundus abnormalities in patients with β-thalassemia and to investigate risk factors for their development.

DESIGN

Cross-sectional, observational study.

PARTICIPANTS

A total of 255 patients with β-thalassemia major (TM) and β-thalassemia intermedia (TI) were consecutively recruited and investigated.

METHODS

Patients underwent best correct visual acuity, indirect ophthalmoscopy, and fundus photography, including fundus autofluorescence (FAF) and near-infrared reflectance imaging using a confocal scanning laser ophthalmoscope (cSLO). Hematologic parameters were determined, including mean ferritin levels, aspartate amino transferase, alanine amino transferase, calcium, pre-transfusion hemoglobin, history of splenectomy, and liver iron concentration. Factors associated with the ocular phenotype were assessed using logistic regression.

MAIN OUTCOME MEASURES

Ocular phenotype as determined by clinical examination and used multimodal imaging.

RESULTS

A total of 153 patients (60.0%) affected by TM and 102 patients (40.0%) affected by TI participated, of whom 216 (84.7%) were receiving iron-chelating therapy. Ocular fundus abnormalities characteristic of pseudoxanthoma elasticum (PXE) were detected by cSLO in 70 of 255 patients (27.8%) and included peau d'orange (19.6%), angioid streaks (12.9%), pattern dystrophy-like changes (7.5%), and optic disc drusen (2.0%). Pseudoxanthoma elasticum-like changes were more frequent in patients with TI (P<0.001). Patients with PXE-like fundus changes were older than patients without these fundus changes (P<0.001). In both patients with TI and TM, age (P = 0.001) and splenectomy (P = 0.001) had the strongest association with presence of PXE-like fundus changes in multivariate analyses. A total of 43 of 255 patients (16.9%) showed increased retinal vascular tortuosity independently of the PXE-like fundus changes, which was associated with aspartate amino transferase (P = 0.036), hemoglobin (P = 0.008), and ferritin levels (P = 0.005).

CONCLUSIONS

Pseudoxanthoma elasticum-like fundus changes are a frequent finding in patients with β-thalassemia. In TI, these changes increase with duration or severity of the disease. This particular ocular phenotype suggests an ocular pathology similar to PXE. Retinal vascular tortuosity may be an additional disease manifestation independent of the PXE-like syndrome. Patients with long-standing disease requiring iron-chelating treatment and a history of splenectomy need regular ophthalmic checkups because they are at risk of developing PXE-like fundus changes and potentially of subsequent choroidal neovascularization.

Multimodal imaging of optic disc drusen

PURPOSE

To evaluate optic disc drusen, extracellular protein deposits known to contain numerous aggregates of mitochondria, using multimodal modalities featuring optical coherence tomography (OCT) and autofluorescence imaging.

DESIGN

Retrospective observational case series.

METHODS

Eyes with optic nerve drusen were examined with enhanced depth imaging (EDI)-OCT, swept source OCT, and fundus autofluorescence using a fundus camera.

RESULTS

Twenty-six eyes of 15 patients with optic disc drusen were evaluated. EDI-OCT and swept source OCT showed multiple optic disc drusen at different levels; most were located immediately anterior to the lamina cribrosa. The drusen were ovoid regions of lower reflectivity that were bordered by hyperreflective material, and in 12 eyes (46.2%) there were internal hyperreflective foci. The mean diameter of the optic disc drusen as measured in OCT images was 686.8 (standard deviation ± 395.2) μm. There was a significant negative correlation between the diameter of the optic disc drusen and the global retinal nerve fiber layer thickness (r = -0.61, P = .001). There was a significant negative correlation between proportion of the optic disc drusen area occupied by optic nerve drusen as detected by autofluorescence imaging and the global retinal nerve fiber layer thickness (r = -0.63, P = .001).

CONCLUSIONS

Deeper-penetration OCT imaging demonstrated the internal characteristics of optic disc drusen and their relationship with the lamina cribrosa in vivo. This study also showed that both the larger the drusen and the more area of the optic canal occupied by drusen, the greater the associated retinal nerve fiber layer abnormalities.

Fluorescein angiographic identification of optic disc drusen with and without optic disc edema

BACKGROUND

The fluorescein angiographic criteria for differentiating optic disc drusen (ODD) from optic disc edema have been unclear. We designed a study to identify distinguishing angiographic features of each and to apply them to cases where both drusen and edema were present.

METHODS

A computer search was performed for cases evaluated in a university academic neuro-ophthalmology consultative practice and coded as ODD; all cases were reviewed, and those with fluorescein angiography were selected for further study. Cases were classified as either buried or surface ODD. Ten cases with papilledema were selected for comparison. Eight cases of coexistent drusen and edema were identified. Autofluorescence, early leakage, early blockage, early and late nodular staining, late peripapillary staining, and late leakage were tabulated.

RESULTS

Two hundred sixteen cases of ODD were identified; 62 (116 eyes) had adequate fluorescein angiography for study. Twenty-three eyes were classified as surface ODD; 90% demonstrated early nodular staining of the disc, with late nodular staining in 90% and late circumferential peripapillary staining in 22%; autofluorescence was visible in 93% with preinjection photography. Eighty-three eyes were classified as buried ODD; 25% demonstrated early nodular staining, with late nodular staining in 29% and late circumferential peripapillary staining in 80%; autofluorescence was visible in 12% of those with preinjection photography. In 9 eyes, buried ODD were present with superimposed true edema. In these eyes, early dye leakage, late nodular hyperfluorescence, and late leakage were present.

CONCLUSION

Early and late fluorescein angiographic features reliably distinguish ODD from edema and may be particularly useful when the conditions coexist.

A case of a young asymptomatic woman with optic disc drusen and vasculitis

Purpose

We present the case of a young woman with optic disc drusen and peripheral vasculitis.

Methods

Diagnosis was based on fundoscopic, optical coherence tomography as well as fluorescein angiography (FA) findings.

Results

An asymptomatic 34-year-old female patient with no systemic pathology was referred to our hospital from her optician for retinal findings. Fundoscopy revealed mild disc swelling that could be attributed to the presence of optic disc drusen in both eyes. There was fundoscopic evidence of periphlebitis in the periphery confirmed by FA findings.

Conclusions

In our case, the unique feature was the presence of optic disc drusen and retinal periphlebitis. The patient's disc configuration may have contributed to a predisposition for vasculitis in addition to vessel tortuosity.

Prevalence of optic disc drusen in an adult Chinese population: the Beijing Eye Study

PURPOSE

This study aimed to determine the prevalence of optic disc drusen and their associations with ocular and general parameters.

METHODS

The Beijing Eye Study included 4439 of 5324 subjects invited to participate (response rate 83.4%). All subjects were aged > or = 40 years. The present investigation involved 8594 (96.8%) eyes of 4324 (97.4%) subjects from whom readable fundus photographs of at least one eye were available. The main outcome parameter was the presence of optic disc drusen defined as round, whitish bodies.

RESULTS

Optic disc drusen were detected in nine (0.1 +/- 0.05%) eyes of eight subjects (five women). The prevalence rate was 0.2 +/- 0.07% (95% confidence interval 0.07-0.33%) per subject. Optic disc drusen were significantly associated with small optic discs (p < 0.001). They were not statistically associated with age (p = 0.90), gender (p = 0.73), intraocular pressure (p = 0.97), refractive error (p = 0.71), visual field defects (p = 0.47) or corrected visual acuity (p = 0.84).

CONCLUSIONS

Optic disc drusen are present in about two in 1000 adult Chinese people in Northern China. The main associated factor is a small optic disc.

Advanced visual field loss secondary to optic nerve head drusen: case report and literature review

BACKGROUND

Optic nerve head drusen (ONHD) is a relatively uncommon condition that results from calcific degeneration of axons within the optic nerve. The abnormal drusen bodies can enlarge, compressing normal nerve structures, and ultimately may result in vision loss. Drusen often are discovered through clinical evaluation with a dilated funduscopic examination. Ancillary testing, including computed tomographic (CT) imaging, B-scan ultrasonography, autofluorescence imaging, nerve fiber layer imaging, and threshold visual field evaluation are helpful to confirm the existence of ONHD and to evaluate for progression of this condition.

CASE REPORT

This case report discusses the clinical presentation of a patient with advanced visual field loss from ONHD and the ancillary testing used to confirm the diagnosis. A complete review of literature on ONHD is discussed.

CONCLUSIONS

Currently, there is no cure or direct treatment for progressive vision loss or complications that may develop from ONHD. Useful diagnostic tools include serial automated threshold visual fields, nerve fiber layer analysis, and fundus photography. It is suggested that ocular hypotensive agents be used to lower intraocular pressure prophylactically to prevent further nerve fiber layer and optic nerve damage.

Optic disc drusen: Complications and management

BACKGROUND

Disc drusen have been found clinically in 0.3% of the population with up to 91% presenting bilaterally. Disc drusen gradually change in their ophthalmoscopic appearance throughout a patient's lifespan. This case highlights the possible ocular complications of disc drusen and the complexity in their treatment because of the risk of visual acuity loss.

CASE REPORT

A 43-year-old patient with documented bilateral buried disc drusen presented without symptoms for a routine examination. A subretinal neovascular membrane (SNVM) one quarter of a disc diameter in size with an adjacent subretinal hemorrhage was observed in the right eye with a small subretinal hemorrhage in the fellow eye. The patient was evaluated by a retinologist who deferred photocoagulation of the SNVM considering its nasal disc location.

CONCLUSIONS

Diagnosing disc drusen is critical because of the serious pathology they can mimic, including disc edema. Although typically benign, patients with disc drusen should be monitored on a regular basis to rule out ocular complications, which can be potentially sight threatening.

The rate of visual field loss in optic nerve head drusen

PURPOSE

To define the rate of visual field loss in patients with optic nerve head drusen (ONHD).

DESIGN

Retrospective chart review.

METHODS

Goldmann visual field (GVF) testing from initial visit and last follow-up examination were quantified using the modified Esterman grid technique. The rate of visual field loss was calculated by comparing the initial GVF to the last follow-up GVF. A comparative analysis of GVF and age at initial evaluation was performed on all patients with an initial GVF only.

SETTING

Tertiary academic care center.

PARTICIPANTS

Inclusion criteria for the rate analysis: (1) diagnosis of ONHD and (2) at least 36 months of follow-up with serial GVF testing.

EXCLUSION CRITERIA

(1) patients with glaucoma or glaucoma-suspect; (2) history or examination evidence for other ocular disease; and (3) drusen-related macular causes of visual loss.

RESULTS

Thirty-two of 292 charts were included in the rate analysis. The rate of visual field loss was 1.58%. There was no statistically significant difference between men and women (P = .74). One hundred eighty patients were included in the initial visual field analysis. There was a significant negative correlation between age and GVF, with older patients having lower GVF scores with a Spearman correlation of -0.42 (P < 0.0001); 73% of these 180 patients had mild, minimal, or no visual field loss.

CONCLUSIONS

The rate of visual field loss for ONHD over a 36-month interval of time was 1.6% per year. Patients with minimal or no visual field loss were younger, and patients with moderate or severe visual loss were older.

Optic nerve head drusen

Optic disc drusen are congenital and developmental anomalies of the optic nerve head seen commonly in clinical practice, often as an incidental ophthalmologic finding during routine exams. Optic disc drusen are a form of calcific degeneration in some of the axons of the optic nerve. Visual acuity is often not affected but the visual fields of these patients can be abnormal and deteriorate over time. Optic disc drusen are familial and are not uncommon. They are thought to be the result of pathology at the level of the optic nerve head itself. The diagnosis can be made with clinical findings combined with B scan ultrasound and computed tomography. In addition, newer modalities using optic nerve head tomography are proving to be very useful. Since children as well as adults are affected, it is important to consider optic nerve head drusen in the differential diagnosis of papilledema or optic nerve swelling.

Visual manifestations of visible and buried optic disc drusen

BACKGROUND

It has been reported that visible optic disc drusen are associated with decreased visual acuity and loss of peripheral visual field. Patients with buried optic disc drusen have not been as well characterized.

METHODS

An observational, retrospective review was made of 92 eyes with funduscopic or ultrasonographic evidence of optic disc drusen. Demographics, presenting symptoms, visual acuity, refractive error, intraocular pressure, presence of an afferent pupillary defect, cup-to-disc ratio, appearance of the optic nerve, and visual field were recorded.

RESULTS

Fifty-one (55%) of the eyes were symptomatic; among them, 63% had symptoms of visual acuity loss, and 49% had symptoms of visual field loss. Seventy-nine (86%) of the optic discs appeared abnormal on ophthalmoscopy, but only 42% of these had visible drusen. Forty-five (49%) of the eyes had a visual field defect, and 73% of these were nerve fiber bundle in type. Overall, 73% of optic discs with visible drusen had abnormal visual fields compared with only 36% of optic discs with buried drusen (P < 0.05).

CONCLUSIONS

Among 92 eyes with optic disc drusen, only slightly more than 50% produced visual symptoms. Fewer than 50% of drusen were visible ophthalmoscopically. Buried optic disc drusen identified by ultrasound had a significantly lower frequency of associated visual field defects than did visible optic disc drusen.

Long term follow-up of retinal nerve fiber layer thickness in eyes with optic nerve head drusen

PURPOSE

To investigate the effect of optic nerve head drusen (ONHD) on the retinal nerve fiber layer (RNFL) thickness during follow-up period.

METHODS

Twenty-three non-glaucomatous eyes having clinically visible ONHD confirmed by colored disc photos were studied. RNFL thickness was determined with Optical Coherence Tomography (OCT). Eyes were re-examined after average of 18 months (ranging between 14 and 22 months). Mean RNFL thickness of each quadrant was compared with previous results at each follow-up visit.

RESULTS

Mean RNFL thickness was 88.43 +/- 10.2 micron at first visit and 90.35 +/- 6.9 micron at follow-up in eyes with clinically visible ONHD. The difference between the mean RNFL thickness measured from inferior, superior, nasal and temporal quadrant at first and follow-up visits was not significant (paired t-test, p > 0.05).

CONCLUSION

The presence of drusen was found to have no effect on RNFL thickness at follow-up visits. OCT may provide a useful means to evaluate and follow up the RNFL thickness in these patients.