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Case Report: Peripapillary Subretinal Neovascular Membranes
By David Meyer, OD
Primary Care Resident, Salt Lake City VA Hospital
Abstract
This case report describes the etiology, treatment, management, and importance of
peripapillary subretinal neovascular membranes (PSRNVMs). PSRNVMs are uncommon networks of
abnormal choroidal blood vessels that occur within one disc diameter of the optic nerve.
Case History
A 90 year-old Caucasian male presented to the Salt Lake VA hospital for a primary care eye
exam. His chief compliant was dry eyes. Significant ocular history included dry ARMD, cataracts,
and dry eye. His current medication included amlodipine, hydrochlorothiazide, lisninopril, terazosin
and warfarin. The patient was taking warfarin because of previous atrial fibrillation and stated
compliance with his medication regimen. The patient also had a history of a hemicolectomy,
hypertension, iron-deficiency anemia, BPH, and knee pain. The patient also mentioned that he felt
like his vision had decreased somewhat since his exam the year before.
Pertinent Findings
The patient was refracted and the following visual acuities were obtained: OD: 20/50- OS:
20/30-. Biomicroscopy revealed dry eye, arcus, and 2+ nuclear sclerotic cataracts which likely
contributed to his decreased vision. The patient was then dilated as part of the routine exam.
Upon examination of the fundus, a large peripapillary hemorrhage was found in the right eye. The
hemorrhage extended from the 7:00 to 11:00 portions of the temporal optic nerve head with an
inner zone directly adjacent to the nerve that appeared to be lighter than the deep-red surrounding
blood. The hemorrhage extended 1DD temporally with well-defined borders. The optic disc did
not appear edematous. Confluent macular soft drusen was also noted. No other posterior segment
abnormalities were seen in the right eye.
The left eye examination revealed a group of exudates superior temporal to the optic nerve
head (ONH). The area temporal to the ONH including the exudates appeared to be slightly elevated
in comparison to the temporal ONH margin. Near the area of elevation the blood vessels had a very
wispy appearance. Like the right eye, the macula had confluent macular drusen. Both ONHs had
shallow cupping and c/d ratios of 0.20 round.
Fundus photos were taken and images from the Spectralis OCT were obtained.
Interestingly, the average-thickness evaluation map on the OCT revealed much more elevation in
the non-hemorrhagic left eye. The cross-sectional views confirmed this elevation by showing a
large separation between the neurosensory layer and the RPE layer. The macular scans displayed
an uneven surface at the RPE which confirmed the appearance of drusen.
At this point, the patient was scheduled to be seen in the retinal clinic the following week.
He was strongly cautioned against head trauma, excessive lifting or bending, and to not take his
medications more than what was prescribed.
Differential Diagnosis
The primary differential diagnosis in this case was hemorrhagic peripapillary subretinal
neovascular membrane (PSRNVM) from exudative ARMD. Other differential diagnoses included
polypoidal choroidal vasculopathy, traumatic choroidal rupture, hemorrhage from optic nerve
drusen, choroidal tumor, CNVM from ocular histoplasmosis, and idiopathic etiology.
Diagnosis
During the following week the patient returned to our clinic for fluorescein angiography
(FANG). FANG was completed without complication and revealed a hypofluorescent hemorrhage
temporal to the ONH in the right eye. The hemorrhage partially obscured a hyperfluorescent
network of blood vessels which correlated to the lighter area noted previously. The pattern was
consistent with CNVM leakage. The network of blood vessels remained hyperfluoresced
throughout the mid and late phases of the procedure. The left eye showed no leakage in the
peripapillary region, although patches of indistinct mild hyperfluorescence were observed. The
patient was sent to the retinal clinic to be further evaluated.
The attending ophthalmologist confirmed the primary diagnosis of PSRNVM secondary to
wet ARMD OD. A Lucentis injection in the right eye was performed that day to the patient without
complication. Despite the peripapillary elevation in the left eye caused by subretinal fluid on OCT,
a PSRNVM was not found. Based on the stability of the vision of the left eye and the lack of a
definitive diagnosis, close observation was recommended. The patient was to return in 4 weeks for
a follow-up exam which included a second injection of Lucentis OD. To date, 3 total injections will
be completed.
Discussion
Peripapillary subretinal neovascular membranes (PSRNVMs) are relatively uncommon
findings which occur within 1 disc diameter of the disc border, with no normal retina separating the
membrane from the edge of the disc1. They are associated with a number of conditions, including
ARMD, multifocal choroiditis, histoplasmosis, congenital disc anomaly, pattern dystrophy, angioid
streaks, optic disk drusen, choroidal osteoma, peripapillary pseudopodal pigment choroidal
atrophy, and can be idiopathic2. ARMD is the most common association at around 45%. PSRNVMs
can cause decreased vision because of subretinal fluid, exudates, or hemorrhage that extends
toward or into the fovea, even when the neovascular membrane is far from the macula 3.
Second-eye involvement of PSRNVMs occur in about 20% of patients after the median time
of 2 months2. The FANG appearance shows that the majority of them are of the occult-type.
Recent research reveals that the vast majority of occult-type PSRNVMs may actually be polypoidal
choroidal vasculopathy masquerading as PSRNVM4. This recent evidence emphasizes the
importance of indocyanine green angiogram to differentiate the two entities.
ARMD-associated PSRNVMs are unique in that most patients do not present with macular
drusen2. The clinical characteristics most associated with PSRNVMs were hemorrhage, exudates,
fibrosis, and peripapillary atrophy4. These findings are extremely important to the clinician while
examining at-risk patients.
Treatment and Management
PSRNVMs are treated in a variety of ways including laser photocoagulation, photodynamic
therapy, transpupillary thermotherapy, and intravitreal anti-VEGF injection3. Photocoagulation has
shown very positive results5, but recurrence rate is still an issue with this type of therapy3.
Currently the most promising treatment is anti-VEGF injection. Studies show that up to 87.5% of
eyes show stabilized or improved vision using this modality6, although specific studies involving
PSRNVMs exclusively have not been performed.
Typically, treatment is begun in order to prevent foveal involvement. Therefore, treatment
is indicated when the PSRNVMs occur temporal to the disc, there is a threat to the macula, and, if
using laser photocoagulation, at least 1.5 clock hours adjacent to the temporal ONH can be spared
of the laser2.
Conclusion
PSRNVMs are atypical presentations of subretinal neovascularization that warrant careful
observation and/or immediate treatment. They are related to a number of other ocular conditions,
and further research is needed to shed more light on the best treatment and management
strategies. Due to the relatively high incidence of second-eye involvement, careful observation of
the fundus along with OCT analysis are indicated for both eyes. The patient presented in this case
report is a very good example of the importance of close observation. FANG is always indicated in
suspicious cases, and indocyanine green angiogram is emerging as a near-necessity, especially if the
neovascular membrane is the occult type. Overall, visual prognosis is fairly good for those
membranes that are treated properly and do not affect the fovea.
Bibliography
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membranes. Retina 2005;25:564-569.
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vasculopathy in presumed age-related peripapillary subretinal neovascular membranes.
Clinical and experimental ophthalmology 2009;37:368-372.
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choroidal neovascular membranes. Retina 1991;11:295-300.
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Ophthalmology 2003;110:879-881.