Intermediate uveitis

The typical symptoms of intermediate uveitis are blurry vision and floaters. Redness, pain in the eye, and photophobia are rare symptoms compared to acute anterior uveitis cases. Bilateral involvement at initial presentation approaches 80%, although it is frequently asymmetric. Eventually, approximately one-third of unilateral cases will become bilateral.

It is critical to take a thorough medical history of your patient, including present and past personal medical history, surgeries, history of trauma, medicines, and family history. Always ask your patient about arthritis, rashes, shortness of breath, swollen lymph nodes, recent headaches, hearing difficulties, hair loss, pigment changes in the skin, a history of ocular trauma, recent insect bites, sexually transmitted diseases (STDs), tuberculosis (TB) exposure, blood in stools, and recent travels.(29-31)

The clinical findings of intermediate uveitis depend on the cause. Up to 50% of cases may have mild to moderate inflammation of anterior eye segments, which includes keratitis precipitates and cells in the anterior chamber. Those findings are most often in children and patients with MS.

Keratitic precipitates (KPs) are white blood cells present on the corneal endothelium. Small, white KPs are a sign of the non-granulomatous type of inflammation, while large, yellowish to brown KPs are significant for the granulomatous type of uveitis.

Competence in examining the anterior chamber is crucial in recognising and monitoring anterior uveitis. Flares and cells in the anterior chamber are signs of intraocular inflammation. Therefore, the cells in the anterior chamber should be graded by severity under high-magnification slit lamp examination in a 1 X 1-mm field of light, as described by the SUN Working Group Grading Scheme for Anterior Chamber Cells, as follows:(32)

• 0 < 1 cell
• 0.5 = 1-5 cells
• 1+ = 6-15 cells
• 2+ = 16-25 cells
• 3+ = 26-50 cells
• 4+ = More than 50 cells

Flare is the presence of proteins in the anterior chamber, and the SUN Working Group proposed the below classification:(15)

• 0 = None
• 1+ = Faint
• 2+ = Moderate (iris and lens details clear)
• 3+ = Marked (iris and lens details hazy)
• 4+ = Intense (fibrin or plastic aqueous)

Vitreous cells are universal findings in patients with intermediate uveitis. Mostly, they are present in the anterior vitreous. The counting of cells is used, using the same principle as mentioned above for the cells in the anterior chamber.

Vitreous haze may be present in severe cases. The SUN classification is as below (it may be very subjective):(33)

• Score 0 – No clinical findings
• Score 1 – Posterior pole clearly visible
• Score 2 – Posterior pole details hazy
• Score 3 – Posterior pole very hazy
• Score 4 – Posterior pole barely visible

Snowballs are aggregates of vitreous cells, mostly located in the inferior vitreous. They are usually white or yellow. They are typical findings in intermediate uveitis, particularly in pars planitis.

Snowbanks are exudates present as plaques in inferior ora serrata. Scleral indentation or indirect ophthalmoscopy is sometimes required to srecognise those findings.

Peripheral periphlebitis is inflammation of peripheral venules and may be present in the form of sheathing. It may appear months or years after the initial presentation.

Complications of intermediate uveitis may be early or late:

• Early: Cystoid macular oedema (28-25% of cases), Optic disc oedema (most often present in children younger than 16), synechiae. Be aware that patients with 6/6 vision may also have the presence of macular oedema.
• Late: Posterior subcapsular cataract, glaucoma, new vessels of the peripheral retina, and retinal ischaemia. Vitreous haemorrhage is most often present in children. Retinal detachments are also described. In addition, cyclitic membranes (fibrovascular tissue) may develop on the ciliary body, which causes hypotony and phthisis of the bulbus. Band keratopathy (corneal calcifications) is one of the late complications as well.

Slit lamp examination is crucial in the examination of patients with anterior uveitis.

Colour fundus photos are useful in checking posterior eye segments and recognising signs of intermediate and posterior uveitis.

Optical coherence tomography is a golden standard in diagnosing uveitis macular oedema. Intermediate uveitis may be complicated with macular oedema, and OCT scans are important in the workup with uveitis patients.

Ultrasound biomicroscopy can be used to evaluate patients with intermediate uveitis. It uses higher frequencies than ocular ultrasound (35-100 MHz) and provides high-resolution images of the pars plana region. It can detect snow banking, cyclitic membranes, vitreous membranes, and peripheral vitreoretinal tractions.

Fundus fluorescein angiography is useful to diagnose and monitor cases of intermediate uveitis.

While mild asymptomatic vitreous cells may not require immediate treatment, any evidence of cystoid macular oedema (CME), neovascularisation of the peripheral retina, extensive vasculitis, or significant vitreous cell requires treatment.

Malignancy and infection must be ruled out before starting non-specific anti-inflammatory therapy.

Treatment of uveitis should be prescribed by an experienced eye care specialist.

Steroids are the most important part of treatment. Local steroid eye drops are used to control the inflammation of the anterior segments (if there is the presence of keratitic precipitates (KPs) and/or cells in the anterior chamber).

Unilateral cases are mostly treated with periorbital steroid injections of Triamcinolone. If they have no effect or if there is bilateral involvement, at the same time, oral prednisolone is the treatment of choice. A purified protein derivative (PPD) test is imperative before starting any patient on systemic corticosteroids if there are any risk factors for tuberculosis (TB). Once the inflammation stabilises, you can taper the oral dose according to disease activity. An H2 blocker or a proton pump inhibitor can be prescribed adjunctively to oral steroids (to protect the stomach). Reluctant cases or those with CME require intravitreal treatment with steroids. The treatment of choice is intravitreal Triamcinolone, intravitreal Dexamethasone implant, and intravitreal implant of Fluocinolone acetonide.

If corticosteroids cannot control the intermediate uveitis or in patients whose disease invariably flares when steroids are stopped, immunosuppressive therapy often is attempted. Immunosuppression or immune modulation is also used as part of steroid-sparing therapy to reduce the ’patient’s requirement for systemic corticosteroids and, therefore, to diminish the adverse effects of systemic corticosteroid therapy.