From the Guidelines
Optic nerve head drusen are benign calcified deposits that do not require specific treatment, but patients should undergo regular eye examinations to monitor for potential complications such as visual field defects. The presence of optic nerve head drusen can be identified by their characteristic appearance as yellowish, refractile bodies visible on ophthalmoscopic examination 1. According to the primary open-angle glaucoma preferred practice pattern, optic disc drusen are considered a condition that can be distinguished from glaucoma, as they do not indicate increased intracranial pressure and are not typically associated with the same level of optic nerve damage 1.
Some key points to consider when evaluating optic nerve head drusen include:
- They are often discovered incidentally during routine eye examinations
- No specific treatment is required for optic nerve head drusen as they are not harmful in most cases
- Patients should undergo regular eye examinations to monitor for potential complications such as visual field defects, which occur in approximately 75% of affected individuals
- These visual field defects typically begin as arcuate scotomas in the inferior nasal quadrant and may gradually progress over time
- Rarely, optic nerve head drusen can be associated with complications like anterior ischemic optic neuropathy or choroidal neovascularization, which would require specific treatment if they develop
It's worth noting that the comprehensive adult medical eye evaluation preferred practice pattern provides information on the prevalence of age-related macular degeneration (AMD) in different populations, but this is not directly relevant to the evaluation and management of optic nerve head drusen 2.
In terms of management, the primary focus should be on regular monitoring and screening for potential complications, rather than attempting to treat the drusen themselves. This approach prioritizes the patient's quality of life and minimizes the risk of morbidity and mortality associated with untreated complications.
From the Research
Definition and Characteristics of Optic Nerve Head Drusen
- Optic nerve head drusen (ONHD) are calcific deposits buried or at the surface of the optic disc 3.
- They are benign acellular calcium concretions that usually form early in life, just anterior to the lamina cribrosa 4.
- ONHD may be associated with progressive visual field defects, anterior ischemic optic neuropathy, or rarer complications 4.
Imaging and Detection of Optic Nerve Head Drusen
- Methods for detecting and imaging disc drusen include B-scan ultrasonography, fundus autofluorescence, and optical coherence tomography (OCT) 3.
- Enhanced depth imaging optical coherence tomography (EDI-OCT) and swept source optical coherence tomography (SS-OCT) can provide unprecedented in vivo detail of ONHD 3.
- Optical coherence tomography angiography (OCTA) can also be used to image ONHD and may assist with diagnosis and evaluation of progression 5.
Visual Field Defects and Optic Nerve Head Drusen
- Most patients with ONHD have visual field (VF) defects, including concentric VF constriction, arcuate scotoma, enlarged blind spot, and unspecific VF defect 6.
- The type and severity of VF defects may differ between eyes with superficial and buried ONHD 6.
- Patients with superficial ONHD tend to have more severe functional and structural impairment than those with buried ONHD 6.
Coexistence of Optic Nerve Head Drusen and Glaucoma
- ONHD can make evaluation of the nerve head difficult to interpret, and visual field defects may resemble glaucomatous damage 7.
- Optical coherence tomography (OCT) can be beneficial in evaluating the nerve fiber layer in patients with coexisting ONHD and glaucoma 7.
- Significant nerve fiber layer thinning can occur in patients with both glaucoma and ONHD, despite the appearance of the optic nerve head 7.