Cryotherapy for presumed parasitic angle granuloma causing acute anterior granulomatous uveitis

Abstract

Dear Editor, An 8-year-old male child attended our outpatient department with complaints of left eye pain, redness and defective vision of 3 weeks duration. He gave history of bathing in the river 1–2 h per day for a period of 2 months prior to the onset of ocular symptoms. The patient had no systemic symptoms and his general examination was normal. His visual acuity was 20/20 OD and 20/60 OS. His intraocular pressure was 14 mmHg in both eyes by applanation tonometry. Slit lamp examination of the left eye revealed fine- and medium-sized keratic precipitates [Fig. 1], 2+ cells and flare, yellow-colored mass at 6 o″ clock position arising from the angle extending on the iris and endothelial surface confined to less than 1 o″ clock hour position [Fig. 2]. Rest of the ocular examination was normal. Blood smear study showed mild eosinophilia and normal morphology of neutrophils, basophils and lymphocytes. No microfilaria or malarial parasites were observed. Stool examination showed no ova, cyst, parasites, ameba or bacteria. Urine microscopic examination was normal. Mantoux was negative and chest X-ray PA view was normal. Based on clinical features and laboratory investigations [Table 1], his condition was diagnosed as presumed nonviable parasitic angle granuloma (PPG). He was treated with topical steroids (1%percent prednisolone acetate hourly), mydriatic eye drops and oral analgesics. Figure 1 Medium-sized keratic precipitates (white arrow) in granulomatous anterior uveitis Figure 2 Angle granuloma at 6 o″ clock position situated between iris (vertical arrow head) and cornea (horizontal arrow) Table 1 Biochemical values of the patient with acute granulomatous anterior uveitis After 3 weeks since topical steroids were not effective in controlling the inflammation, limbal cryotherapy (LC) was performed under short general anesthesia. Following peritomy, a 2-mm cryoprobe was placed 1 mm behind the conjunctivocorneal junction. Each cryofreezing lasted for 15 s. At the end of 15 s, rapid thawing was induced by irrigating the ice ball with normal saline. In total, three such applications were performed within the 1 o″ clock hour position at the base of the granuloma. Time interval between each application was 10 s. The tip of the probe was placed gently over the site, avoiding undue pressure. By this technique, approximately 1.3 clock hour area received cryotherapy at the base of the granuloma followed by topical steroids. Granulomatous anterior uveitis regressed completely in 6 weeks. Corneal opacity with peripheral anterior synechiae was observed at the site of PPG [Fig. 3]. At the end of 5 months follow-up, the treated eye had normal vision, tension and fundus. There was no recurrence of uveitis. Figure 3 (a) Angle granuloma not responding to steroid. (b) Two months after limbal cryotherapy granuloma regressed and uveitis controlled. Endothelial opacity seen at 6 o″ clock position Anterior granulomatous uveitis due to nonviable parasite is a recognized clinical[1] entity. Our patient's condition resembles trematode-induced granulomatous uveitis[2] described by Rathinam et al., but, in our experience, response of PPG to topical steroid eye drops or surgical excision was unpredictable and unsatisfactory. Because surgical manipulation of[3] nonviable parasite can cause exacerbation of inflammation, we performed limbal cryotherapy. Even though eosinophilia is a feature of visceral larva migrans,[4] decline of serum IgE following ocular cryotherapy rules out intraocular and visceral parasite. Our LC is different from[5] cyclodestructive cryotherapy. Limbal stem cells deficiency and hypotony are potential complications. In conclusion, LC along with topical steroids is effective in treating PPG involving less than 1 o″ clock hour position in angle.