Myopic CNV – September 2015

September 2015

Case History

The patient is a 53 year-old male, who was referred to Illinois Retina Associates for a macular lesion in his right eye. He presented to the referring doctor’s office with a complaint of visual distortion in his right eye for the past 8 months. The patient is known for high myopia (-9.50) in both eyes, and is otherwise healthy.  His visual acuity was 20/50 OD and 20/25 OS.

Posterior Segment Exam

On examination, in addition to myopic tilted optic discs and peripapillary atrophy in both eyes, there was a raised grey-green subfoveal lesion in his right eye, surrounded by small subretinal and intraretinal hemorrhages [Figure 1]. His left eye had macular myopic lacquer cracks [Figure 1].

Figure1
Figure1

Diagnostic testing

Fluorescein angiography of the eye revealed a classic subfoveal membrane [Figure 2].

Figure 2
Figure 2

In the left eye, there was a window defect corresponding with the clinically observed lacquer cracks. There was no leakage suggesting choroidal neovascularisation [CNV] in the left eye. Optical coherence tomographic [OCT] angiography clearly showed the location of the CNV in the outer retina and choriocapillaris layers [Figure 3].

Figure 3
Figure 3

OCT imaging showed a myopic fundus with posterior staphylomas in both eyes [Figure 4 & 5]. In the right eye, there was a subretinal heterogenous hyperreflective lesion in the center of the fovea, surrounded by a cuff of subretinal fluid [Figure 4]. the left eye retinal architecture was within normal limits [Figure 5].

Figure 4
Figure 4
Figure 5
Figure 5

Differential Diagnosis:

Common causes of CNV include:

  • Age-related macular degeneration
  • Acquired myopia
  • Idiopathic
  • Inflammatory conditions [white-dot syndromes]
  • Post infections [presumed ocular histoplasmosis, toxoplasmosis, syphilitic choroiditis]
  • Trauma with Bruch’s membrane rupture
  • Angioid

Diagnosis

Given the presence of high myopia and clearly identified lacquer cracks in the left eye, the most probable diagnosis was a CNV related to myopic degeneration.

Treatment and Follow-Up

The patient was treated with an intraocular injection of Aflibercept. On follow-up one week later, although the visual acuity remained unchanged, angiography [Figure 6] showed that the membrane had significantly decreased in size. He will return in 4-6 weeks for repeat OCT and possible retreatment with Aflibercept.

Figure 6Figure 6

Discussion

Myopia is a very common ocular finding, affecting 25% of the US Population, while pathologic myopia (over -6.00 D) is only present in 2%. Patients with pathologic myopia are prone to a number of complications due to progressive elongation of the eye and thinning of ocular structures, including the retina, RPE and choroid. Some characteristic findings in pathologic myopia include:

  • Peripheral retinal degenerations [lattics, cystoid, paving-stone]
  • Gyrate atrophy of the RPE and choroid
  • Peripheral retina thinning or hole formation
  • Retinal detachment
  • Optic nerve tilting and peripapillary atrophy
  • Posterior staphyloma, which is a localized thinning and ectasia of the posterior sclera, choroid and RPE
  • Elongation and atrophy of the ciliary body, which could lead to phacodonesis
  • Lacquer cracks, which are spontaneous ruptures of the Bruch’s membrane in the posterior pole
  • Isolated subretinal hemorrhages related to lacquer cracks
  • Forster-Fuchs spots are hyperpigmented spots due to RPE hyperplasia in response to nonprogressing CNV
  • CNV

CNV may occur in up to 10% of patients with pathologic myopia, and is often associated with lacquer cracks and/or chorioretinal degeneration. Possible treatments for CNV include laser therapy, photodynamic therapy, and anti-VEGF injections. Laser therapy can be considered only for nonsubfoveal lesions, due to the risk of vision loss. Photodynamic therapy has been shown to prevent vision loss from subfoveal CNV in pathologic myopia. However, anti-VEGF therapy is the tretament option with the best results, leading to complete CNV involution and improvement in vision. Patients with myopic CNV typically require fewer injections than patients with wet macular degeneration.

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