Scleral buckle infection by Serratia species.

We describe a rare case of scleral buckle (SB) infection with Serratia species. A 48-year-old male with a history of retinal detachment repair with scleral buckling presented with redness, pain, and purulent discharge in the left eye for 4 days. Conjunctival erosion with exposure of the SB and scleral thinning was noted. The SB was removed and sent for culture. Blood and chocolate agar grew Gram-negative rod-shaped bacillus identified as Serratia marcescens. On the basis of the susceptibility test results, the patient was treated with oral and topical antibiotics. After 6 weeks of the treatment, his infection resolved.

Introduction

Scleral buckling with explants is an important and effective technique to reattach the retina. Extrusion and infection of the scleral buckle (SB) are the two most common indications for SB removal.[1] Many organisms have been implicated as a cause of SB infection. This is the first reported case of buckle infection due to Serratia species.

Case Report

A 48-year-old male was referred to our department with complaints of redness, pain, watering, and sticky discharge in his left eye for the past 4 days. He had undergone scleral buckling surgery with cryotherapy in that eye for a traumatic rhegmatogenous retinal detachment 28 years ago. Examination revealed a best correct visual acuity (BCVA) of 6/9 and counting finger close to face in the right and left eye, respectively. Anterior segment examination of the right eye was normal with early cataractous changes noted in the right eye. Fundus examination of the right eye was normal. Lid edema with conjunctival congestion was noted in the left eye. A reddish-brown, small exposed SB element was noted lying on the surface of the cornea. Fundus evaluation of the left eye was not possible due to advanced cataract. Ultrasonography of the left eye revealed a well-attached retina. A decision to remove the sclera buckle along with scleral patch graft was taken. Injection cefotaxime 1 g i.v. twice a day and injection gentamicin 60 mg i.v. thrice a day was given before surgery.

Intraoperatively, the sclera buckle was explanted under general anesthesia. The buckle material was solid silicone rubber which showed reddish-brown-pigmented material over the exposed portion of the buckle [Figure 1a]. Scleral thinning was noted in the superonasal area unmasking the underlying choroidal tissue [Figure 1b]. The globe was well formed. Scleral patch graft was not required.

Figure 1

Buckle infection by Serratia marcescens. (a) Explanted scleral buckle showing reddish-brown deposits over the exposed portion of the buckle. (b) Scleral thinning with underlying uveal tissue noted. (c) Growth on both chocolate and blood agar. (d) Microscopic image showing Gram-negative rod-shaped bacillus identified as Serratia species

Postoperatively, the patient was started on tablet ciprofloxacin 750 mg twice a day, topical besifloxacin eye drops 10 times a day, topical lubricants 4 times a day, and topical fluorometholone eye drops 4 times a day.

Culture of the sclera buckle on both blood and chocolate agar revealed infection by Serratia marcescens species which was sensitive to ciprofloxacin [Figure 1c and d]. Hence, the patient was continued on the same set of medications.

Six weeks postoperatively, his BCVA was counting fingers at 1 m in the left eye and no signs of infection. His ocular examination revealed an advanced cataract in the left eye for which he was advised cataract surgery.

Discussion

SB infection and extrusion remain fairly uncommon complications following scleral buckling surgery. Their estimated incidence varies from 0.2% to 5.6%.[23456] Coagulase-positive and coagulase-negative Staphylococci are implicated as the most common organisms causing SB infection (70%–90% of cases).[6] However, rarer cases with infections due to atypical mycobacterium, corynebacteria, and fungi have been reported.[7]

S. marcescens, a rod-shaped, Gram-negative bacillus classified as a member of the Enterobacteriaceae, is a widely distributed saprophytic bacterium, and has been found in food, particularly in starchy variants which provide an excellent growth environment. S. marcescens produces a pigment called prodigiosin.[8] In our case, the patient presented with an exposed buckle increasing his risks significantly of acquiring an infection. In a report by Smiddy et al.,[6] 45 cases of SB infection among approximately 3000 scleral buckling procedures performed at their institution between July 1, 1985 and July 1, 1991 were identified. The SB was exposed in all 45 cases. S. marcescens being a saprophytic bacterium, the necrotic conjunctival and scleral tissues provide an excellent environment for the Serratia species to grow.

Conclusion

This case report is the first to describe buckle infection with Serratia species. We have also demonstrated the proper management of this case with the removal of the SB and postoperative use of oral fluoroquinolones. Ophthalmologists should be aware of this rare type of virulent bacterial infection.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.