Diagnosis & differential diagnosis

Patient history is essential in determining the diagnosis. Long standing floaters are often due to relatively benign conditions and do not represent an emergency. However, recent progressive onset of symptoms is highly suggestive of RD. Patients with sudden symptoms of new flashing lights, floaters or monocular loss of central or peripheral vision should be promptly evaluated by an ophthalmologist. If flashes or floaters are the only symptoms, the examination should urgently take place within a few days. However, in case of any visual loss, the examination should take place within 24 hours.

The eye examination should include check the vitreous for hemorrhage, detachment, and pigmented cells. Evaluation includes dilation of the pupil for indirect ophthalmoscopy combined with scleral depression to detect all retinal breaks. Slit-lamp biomicroscopy with a mirrored contact lens or a small indirect condensing lens may complement the examination. B-scan ultrasonography is useful to evaluate the peripheral retina and in case of vitreous hemorrhage.

Patients with subjective visual loss or vitreous pigment or hemorrhage on slit lamp examination should be considered at increased risk of retinal tear. Patients with uncomplicated PVD are at a small but significant continued risk (~3.5%) of subsequently developing retinal tear and detachment over the weeks after diagnosis. Fellow eye must always be carefully examined. If retinal breaks without detachment are detected, they may be treated on an outpatient basis with retinopexy (Fig. 4) (laser treatment applied to the retinal break and retinal pigment epithelium in order to induce the formation of a scar or, in some cases, cryotherapy). If a RD is detected, prompt surgical treatment is required.

Differential diagnosis

Differential diagnosis includes other peripheral retinal degenerations, such as lattice degeneration, retinal tufts, retinoschisis. Though these conditions may mimic RD, they have distinctive features that support the correct diagnosis. In case of uncertain diagnosis, additional examinations (e.g. laser spot test, B-scan ultrasonography) should be performed. Classic migraine with visual aura and occipital lobe disorders with migraine-like symptoms (ischemia, hemorrhage, arteriovenous malformation, epilepsy, neoplasms) should also be considered in the differential diagnosis. Postural hypotension can produce brief flashes or dimming of vision in all or part of the binocular visual field. Advanced proliferative diabetic retinopathy can lead to vitreous hemorrhage and mimic floaters associated with PVD.