Woman referred for pressure in left eye

In the left eye, IOP was 33 mm Hg, extraocular muscle movements were limited in all positions of gaze, and gonioscopy revealed a narrow angle.

A 53-year-old woman was referred from an outside ophthalmologist for evaluation of left eye pain. The patient initially presented to an ophthalmologist with a 2-day history of a pressure-like sensation in the left eye that evolved into a headache. She also had redness of the left eye. She was unaware of the diagnosis given by this ophthalmologist, but she took tobramycin-dexamethasone eye drops four times a day as prescribed.

The patient subsequently experienced worsening pressure sensation in her left eye and onset of nausea and vomiting. Although there was no change in vision or halos, she had photophobia. At this time, she sought care from a second outside ophthalmologist, who upon examining her left eye found narrow angles and IOP of 36 mm Hg. She was subsequently given brimonidine-P 0.15%, dorzolamide hydrochloride-timolol maleate and latanoprost. The pressure decreased to 22 mm Hg, and the patient was sent to New England Eye Center for urgent evaluation.

History

Shazia Ahmed

My Hanh T. Nguyen

The patient’s ocular history included diabetic retinopathy in both eyes status post-panretinal photocoagulation and a history of retinal detachment in the left eye in 1994 that was repaired with pars plana vitrectomy and scleral buckle. She had a complicated medical history, including diabetes mellitus, status post-renal transplant, status post-coronary artery bypass graft, hypothyroidism, status post-implantable cardioverter defibrillator, hypertension, hypercholesterolemia and osteoporosis.

She had no known drug allergies. Her medications included insulin pump, prednisone (for the renal transplant), mycophenolate mofetil, cyclosporine, levothyroxine, aspirin, metoprolol, furosemide, lisinopril, clopidogrel, ezetimibe, nitroglycerin patch, omeprazole, rocaltrol, risedronate and multivitamins. She denied use of tobacco, alcohol or illicit drugs. Family history was noncontributory.

Examination

On examination, the patient’s best corrected visual acuity was 20/30 in the right eye and finger counting at 3 feet in the left eye. She reported this was her baseline visual acuity. Her pupils were reactive to light, although sluggish in the left eye. There was no relative afferent pupillary defect. IOP measured by applanation was 13 mm Hg in the right eye and 33 mm Hg in the left eye. Extraocular muscle movements were full in the right eye, although limited in all positions of gaze in the left eye (Figure 1).

External examination revealed trace lid swelling of both eyelids. Hertel measurements were 14 mm in the right eye and 18 mm in the left eye. The conjunctiva was white and quiet in the right eye. The left eye had a quiet perilimbal conjunctival zone; however, several millimeters posterior to the limbus, there was 360° of 3+ deep red injection (Figure 2). There was no conjunctival or corneal staining. The cornea was clear without edema. The anterior chamber was shallow and quiet in both eyes. There was no neovascularization of the irides. The lens in the right eye had 2+ nuclear sclerotic cataract. The left eye had a 4+ brunescent cataract.

Gonioscopy revealed an open angle in the right eye. The left eye had 90° of anterior trabecular meshwork and 270° of no angle structures visible. The posterior segment examination revealed normal discs in both eyes. There was evidence of moderate diabetic retinopathy and panretinal photocoagulation scars in both eyes. A scleral buckle was noted in the left eye.

Versions in the nine cardinal gazes at the time of presentation. Note severe limitation of all positions of gaze in the left eye.

External photograph of the left eye showing deep red injection of the conjunctiva beginning 3 mm from the limbus. Images: Yoon MK, Bauman C

What is your diagnosis?

Complicated findings

The differential diagnosis for this patient must take into account all the various findings on examination and the complicated medical history. The primary reason for transfer of care was to evaluate the elevated IOP. Malignant glaucoma would be unlikely in the patient who had not had any ocular intervention in many years.

Ciliary body effusion has been reported after a scleral buckling procedure, but an acute rise in IOP more than 10 years after surgery would be unexpected. Phacomorphic glaucoma could help explain the unilateral narrow angle and moderate IOP elevation, but this would not likely account for the patient’s findings of limited extraocular muscle movements, proptosis and pain.

Conditions that are potentially life-threatening and must be treated immediately if they are present include mucormycosis and orbital cellulitis. The patient is a poorly controlled diabetic, which predisposes her to these conditions. Thus, an emergent CT scan, complete blood count and electrolyte analysis must be performed. Imaging would also help identify the presence of thyroid eye disease, the most common cause of proptosis in adults.

The patient also had proptosis and conjunctival injection 360°. An infection of the scleral buckle could cause orbital and scleral inflammation, although there was no extrusion of the buckle on examination. Inflammatory processes such as sarcoidosis, Wegener’s granulomatosis or idiopathic orbital inflammation and infectious etiologies such as tuberculosis and syphilis could affect the orbit and eye in this manner. Thus, a systemic workup is indicated.

Diagnosis

A laser peripheral iridotomy was performed in the left eye because of the narrow angle. Despite this, IOP remained elevated at 28 mm Hg. The angle was more open after the procedure, but the patient’s symptoms were unchanged.

An emergent CT scan of the orbits and face as well as blood work including complete blood count, complete metabolic panel, erythrocyte sedimentation rate, C-reactive protein, ANA, rheumatoid factor, ANCA and RPR were then obtained. The CT scan (Figure 3) showed no extraocular muscle thickening, no orbital masses or abscesses, clear sinuses and the scleral buckle in place. The blood work was normal except for electrolyte abnormalities secondary to the renal transplant. Thus, orbital cellulitis, mucormycosis, thyroid eye disease and tumor were ruled out. A chest X-ray was normal with no hilar adenopathy or masses.

Subsequently, a B-scan was performed in the clinic to evaluate the posterior segment (Figure 4). This showed thickening of the posterior sclera in the left eye with a positive “T sign.” There was no retinal detachment.

At this point the differential diagnosis was idiopathic posterior scleritis or infected scleral buckle. Despite the low likelihood of an infectious process, intravenous vancomycin and ceftazidime were initiated. Oral nonsteroidal anti-inflammatory medications were started as well. Eye drops in the left eye included prednisolone acetate 1% four times a day (for post-laser inflammation), dorzolamide hydrochloride-timolol maleate twice a day and brimonidine-P 0.15% three times a day.

The next day, the patient reported no improvement in eye pain, nausea or vomiting. Her visual acuity and extraocular muscle movements were also unchanged. IOP was 30 mm Hg. At this point, the oral prednisone dose was increased from the patient’s baseline of 5 mg to 40 mg daily.

On hospital day number 3, she had a marked improvement in symptoms. She reported no further pain, nausea or vomiting. Her extraocular muscle movements were now approximately 80% of the full motions. There was much less injection of the eye. The vision, however, was unchanged. The patient was diagnosed with idiopathic posterior scleritis. She was discharged and placed on a quick taper down of the oral prednisone to her previous dose of 5 mg daily.

Coronal (left) and axial (right) CT scan images showing no extraocular muscle thicknening, no masses and clear sinuses.

B-scan ultrasound image showing a "T sign."

Discussion

Posterior scleritis is an uncommon form of scleral inflammation that occurs posterior to the ora serrata. Although occurring most commonly in patients over 40 years old, the age range has been reported from 11 to 84 years. There is a female preponderance of 2-to-1. Less than one-third of cases are bilateral.

The presenting symptoms can vary. Typically there is a component of periocular pain and headache. Pain with eye movements, proptosis, diplopia and changes in vision commonly occur. On examination, there is evidence of anterior scleritis in 59% of patients. Associated findings include swollen optic disc, choroidal folds and exudative retinal detachment.

The majority of cases are idiopathic in nature. Only 29% of cases have systemic associations. Rheumatoid arthritis, acne rosacea, Behçet’s disease, Crohn’s disease, dermatomyositis, gout, herpes zoster, IgA nephropathy, bacterial/fungal infection, periarteritis nodosa, porphyria, pyoderma gangrenosum, Reiter’s disease, relapsing polychondritis, sarcoidosis, Still’s disease, syphilis, systemic lupus erythematosus, Takayasu’s disease, giant cell arteritis, tuberculosis, ulcerative colitis and Wegener’s granulomatosis have all been described.

Posterior scleritis is believed to be an immune-mediated process. Histopathologic sections have shown polymorphonuclear cell infiltration with minimal necrosis. The appearance is similar to idiopathic orbital inflammation (pseudotumor).

Work-up involves laboratory work including CBC, ESR, ANA, RF, ANCA, VDRL or FTA-ABS, LFTs, chest X-ray, urinalysis and PPD. B-scan ultrasound is the most sensitive test for detecting thickening of the sclera. The “T sign” is found in about 50% of cases, which represents edema in the episcleral Tenon’s space. This is a non-specific finding that can also be found in other forms of inflammation. The fluid collection can cause vision changes secondary to a shorted axial length. CT or MRI may play an associated role in ruling out other conditions, but they are not suggested as a primary method of diagnosing posterior scleritis.

Treatment includes systemic or peribulbar corticosteroids. Anterior subconjunctival injection is contraindicated because there is a risk of scleral perforations. Oral nonsteroidal anti-inflammatory agents can be effective with symptoms. If refractory to oral steroids, immunosuppressants such as cyclophosphamide, chlorambucil, or cyclosporine may be considered.

Some patients respond well to the treatment and can achieve remission in several days. However, reports have shown that up to 31% will have decreased vision, and 3% have vision less than 20/200.

For more information:

• Michael K. Yoon, MD, and Caroline Baumal, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site: www.neec.com.

• Edited by Shazia Ahmed, MD, and My Hanh T. Nguyen, MD. Drs. Ahmed and Nguyen can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site: www.neec.com. Drs. Ahmed and Nguyen have no direct financial interest in the products mentioned in this article, nor are they paid consultants for any companies mentioned.

References:

• Benson WE. Posterior scleritis. Surv Ophthalmol. 1988;32(5):297-316.
• Calthorpe CM, Watson PG, McCartney ACE. Posterior scleritis: a clinical and histological survey. Eye. 1998;2:267-277.
• Chaques VJ, Lam S, et al. Computed tomography and magnetic resonance imaging in the diagnosis of posterior scleritis. Ann Ophthalmol. 1993;25:89-94.
• McCluskey PJ, Watson PG, et al. Posterior scleritis: clinical features, systemic associations, and outcome in a large series of patients. Ophthalmology. 1999;106(12):2380-2386.
• Munk P, Nicolle D, et al. Posterior scleritis: ultrasound and clinical findings. Can J Ophthalmol. 1993;28(4):177-180.
• Quinlan MP, Hitchings RA. Angle-closure glaucoma secondary to posterior scleritis. Br J Ophthalmol. 1977;61(2):76-85.