|Year : 2004 | Volume
| Issue : 4 | Page : 321-2
Utility of computed chest tomography (CT scan) in recurrent uveitis.
Lilavati Hospital and Research Center, Mumbai, India
|Date of Submission||27-Mar-2003|
|Date of Acceptance||05-Sep-2003|
Lilavati Hospital and Research Center, Mumbai
Source of Support: None, Conflict of Interest: None
In recurrent uveitis CT scan could be a superior imaging modality when a primary pulmonary pathology is suspected. Two such cases are illustrated.
Keywords: Uveitis, tuberculosis, sarcoidosis, x-ray, computed tomography
|How to cite this article:|
Mehta S. Utility of computed chest tomography (CT scan) in recurrent uveitis. Indian J Ophthalmol 2004;52:321
Numerous systemic diseases especially infections (tuberculosis, syphilis, leprosy) and autoimmune disorders (sarcoidosis, Crohn's disease, leptospirosis) may produce varying manifestations of anterior and posterior uveitis. Systemic evaluation of patients with active uveitis remains important to permit accurate diagnosis, appropriate treatment and to reduce the possibility of recurrence. Recurrent attacks may produce an increase in ocular morbidity due to a poorer final structural and visual outcome. We report two cases of recurrent uveitis where past and present chest X-rays were normal, but the chest CT enabled accurate diagnosis. This allowed specific therapy and better outcomes.
| Case report|| |
Case 1. A 33-year-old male patient presented with a history of defective vision in the right eye for the past 2-3 months. He had no systemic complaints. About 18 months earlier, he had sought medical assistance for a similar complaint in both eyes. A review of the available records showed findings suggestive of bilateral acute severe anterior uveitis with complications (cataract and secondary glaucoma) in the left eye. He had subsequently undergone cataract surgery with intraocular lens implantation with a trabeculectomy in the left eye. Previous records indicated a normal chest X-ray. The haemoglobin (Hb) estimation, white cell counts and blood sugar levels (fasting and post-prandial) were also within normal limits. On examination, his best-corrected visual acuity was counting fingers close to face in the right eye and 6/12 in the left eye. The right eye showed multiple fine keratic precipitates, grade 2 cells and flare in the anterior chamber, posterior synechiae, posterior subcapsular cataract and cells in the anterior vitreous. The left eye showed a filtering bleb superiorly and an intraocular lens within the capsular bag. There was no evidence of active uveitis in the left eye. Dilated fundus examination was not possible in the right eye because of the cataract. In the left eye, there was advanced glaucomatous damage to the disc manifested by a cup:disc ratio (CDR) of 0.9 and rim pallor. The retina and macula were normal. Intraocular pressure in the right and left eye was 14 and 34 mm Hg respectively. A diagnosis of recurrent uveitis was made. A repeat Hb estimation, white cell counts and erythrocyte sedimentation rates (ESR) were normal. A Mantoux test was strongly positive with induration of 34 x 20 mm and overlying ulceration. A repeat chest X-ray was also normal [Figure - 1]. A computed tomogram of the chest was done, revealing lymphadenopathy in the prevascular space. The periphery of the lymph nodes enhanced on injection of contrast with central non-enhancing areas suggestive of tuberculous lymphadenopathy with central necrosis [Figure - 2]. Sarcoidosis was ruled out with normal angiotensin converting enzyme (ACE), serum calcium and 24-hour urinary calcium estimations.
The patient was started on a four-drug regime (isoniazid, rifampicin, ethambutol and pyrazinamide) and topical corticosteroids (Prednisolone acetate 1%). At last follow-up there was significant reduction in the activity of the uveitis, the presence of the complicated cataract precluding any improvement in the visual acuity. After three months of anti-tuberculous therapy he underwent an uncomplicated cataract extraction (phacoemulsification) with intraocular lens implantation. The vision improved to 6/9 in the right eye.
Case 2. A 55-year-old female presented with episodes of defective vision and mild pain in the left eye for the last 12 months. She had a history of operated retinal detachment in the right eye approximately 20 years ago. Previous reports suggested at least 3 episodes of an acute severe left-sided uveitis. An earlier series of investigations including Hb, white cell counts and chest X-ray were normal. A previous fundus fluorescein angiogram revealed cystoid macular oedema (CME) in the left eye. Her best-corrected visual acuity was 6/60 in the right and 6/12 in the left eye. Examination of the right eye did not reveal any evidence of uveitis. The left eye showed numerous keratic precipitates; grade 3 aqueous cells and flare, pars plana exudation (snow-banking) with numerous white fluffy vitreous "snowballs". A diagnosis of recurrent intermediate uveitis was made and she was reinvestigated. Her repeat chest x-ray was normal [Figure - 3] but a mediastinal lymphadenopathy was seen on CT scan, which enhanced uniformly on contrast injection without evidence of central non-enhancing areas [Figure - 4]. A Mantoux test (5 TU) was negative and the ACE was elevated. This suggested a diagnosis of sarcoidosis. She was started on longterm corticosteroids (Prednisolone 60 mg/day tapering by 10-mg. every month). There was a marked reduction in the activity of the uveitis and she has remained free of recurrence for the past six months. The visual acuity improved to 6/9 in the affected eye.
| Discussion|| |
Mediastinal lymphadenopathy has been well described in numerous conditions including systemic infections (tuberculosis), autoimmune disorders (sarcoidosis) and lymphoproliferative disorders (lymphomas, leukemia). Conventional X-rays image the mediastinum inadequately due to the interference of the sternum and soft tissue such as trachea and the oesophagus. A CT scan is required for detection, and assessment of the adenopathy. In Case 1, a normal earlier chest X-ray may have suggested the absence of pulmonary tuberculosis. A CT scan during his recurrence helped in the diagnosis of active pulmonary tuberculosis and permitted specific therapy. Isolated tuberculous mediastinitis is a well-described manifestation of pulmonary tuberculosis in patients of south Asian origin,  with numerous case series reporting mediastinitis with normal lung parenchyma and pleura. 
Sarcoidosis commonly presents as an isolated mediastinal lymphadenopathy with no parenchymal pathology.  Routine x-rays are of limited utility in these cases and a CT scan is more useful. In one large series Kaiser et al found that CT scans were able to detect sarcoidosis in 14 of 17 cases that were missed on routine X-rays. In Case 2, the presence of a typical CT scan appearance in conjunction with the other laboratory investigations, led to a clinical diagnosis of sarcoidosis.
In these two cases, recurrent uveitis suggested the possibility of an untreated active systemic disease. Chest CT due to its better mediastinal imaging allowed us to detect and assess previously undetected pathology and led to a better final outcome. Computed tomography may be preferable for chest evaluation in cases of recurrent uveitis.
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[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4]