Vitreous cyst is particularly rare structural malformation that can occur in Healthy eyes or associated with intraocular pathology that can be completely asymptomatic or cause transient visual disturbance, especially with changing head position in some patients 1, 2. They can be fixed or free floated, pigmented or non-pigmented, single or multiple as well as unilateral or bilateral 3.
Congenital cysts usually are stable, remain unchanged for a lifetime and rarely cause visual symptoms. They are not accompanied by ocular pathology and may be associated with the remnants of the hyaloid Artery such as Bergmeister’s papilla and Mittendorf’s Dot and consider as a choristoma 1, 4, 5.
Acquired cysts may occur secondary to degenerative disease of retina and choroid 6 like Retinitis pigmentosa 7, high myopia with uveal coloboma 8 or other forms of intraocular inflammation such as Toxoplasmosis 9 or intermittent uveitis 10 and ocular trauma and retinal surgery 11.
In this paper, we report the clinical and instrumental findings of a pigmented vitreous cyst in two patients.
A healthy 41-year-old woman referred to our ophthalmology clinic complaining of a transient visual disturbance and floater in the central visual field of her right eye from many years ago; her symptoms worsen over the last two months as reported by increasing motility of the shadow, and were diminishing her visual acuity in her daily activities.
She had no previous history of trauma, infections or inflammatory ocular disease. Her ophthalmologic examination showed best-corrected visual acuity of 20/20 in both eyes with -1 dioptres. In slit lamp examination, there were no abnormal findings in anterior segment structures in both eyes, and her intra-ocular pressure was 14 mmHg bilaterally. Fundoscopy revealed a posteriorly located pigmented free-floating vitreous cyst without any adhesion to intraocular structures and incomplete Posterior vitreous detachment (PVD) in the right eye. Left eye fundoscopic examination was completely normal.
The cyst was a brownish-pigmented oval lesion with a smooth surface that was translucent at some places. The cyst made frequent movements with changing head posture that sometimes occluding the visual axis (Figure 1).
A-scan ultrasonography showed two peaks of a medium to high reflectivity in the posterior vitreous space, and B-scan ultrasonography showed a spherical cyst with a maximal diameter of 1.25 mm, with no internal reflectivity. The cyst was located in the centre of the vitreous cavity without any attachment. (Figure 2)
Spectral-domain optical coherence tomography (SD OCT) (Spectralis; Heidelberg, Heidelberg, Germany) with Raster Scan Pattern showed a round, hyper reflective crust with hypo reflective contents. The cyst appears as a reflected image with shadowing of the underlying retina (figure 3).
Fluorescein angiography of retina showing the cyst without any vascular connection to choroidal and retinal vessels or any sign of retinitis or vasculitis (figure 4).The pigment clusters were absent from auto fluorescence, but they looks hyper reflective infrared image (figure 5).
A 18-year-old boy was referred to our eye hospital because of visual symptoms in the left eye. He reported a black object floating in his left eye from three years ago after severe blunt trauma to his left eye in football game that was treated with some ophthalmic drops. After 1-2 month, he found out that a black object move around his visual field, especially when reading his books, and he mentioned about transient blurring of vision in his left eye when changing head position or look down. His medical history was unremarkable. The patient’s best-corrected visual acuity was 10/10 in both eyes. In Slit-lamp examination, anterior segment in both eyes was normal. Fundus examination of the left eye showed a free floating, round, semi-transparent, and at some places pigmented vitreous cyst with a smooth surface just below the inferior nasal vascular arcades but there is not any retinal break (figure 6). Fundus examination of the right eye was normal. The cyst made frequent movement’s bye changing head posture and sometimes blurred his vision. Unfortunately, he refused Furthermore evaluation and left the clinic.
Free-floating Vitreous cysts are usually incidental clinical findings that appears as oval or spherical, pigmented or non-pigmented, single or lobulated bodies in the vitreous cavity.12
Free-floating Vitreous cysts are usually incidental clinical findings that appeared as oval or spherical, pigmented or non-pigmented, single or lobulated bodies in the vitreous cavity.12Vitreous cyst classified into congenital and acquired, and it was considered to originate from a dislodged ciliary epithelium, from a cystic growth in retinal coloboma, from the hyaloid artery remnants like Bergmeister’s papilla and Mittendorf’s dot or as a vitreous reaction to underlying retinal or choroidal degeneration or inflammatory process.13
The hypothesis of a residual hyaloid artery as a vitreous cyst’s origin is supported by histopathological findings of Nork and Millecchia 14, which propose that the cyst is a choristoma of the primary hyaloid system. Orellana et al. studied aspirated idiopathic pigmented vitreous cysts by electron microscope and observed that mature and immature melanosomes in the pigmented cells supporting the theory that cysts originate from pigment epithelial cells 15.
Both of our patients had only mild visual symptoms, so, cyst removal and histopathological analysis were not performed, and we search for the exact origin of the cyst. Both patients had no history of ocular inflammation and had a unilateral, solitary cyst. The first patient had no history of trauma and in examination; we found an oval, brownish-pigmented cyst without any extension to intra ocular structure. The patient’s sudden symptoms of a dark floater could be caused by PVD, which might produce dislocation of the cyst from the attachment to the optic disc.