Necrotizing Scleritis Associated with 5-Fluorouracil and Sub-Tenon’s Block in Patient with Previous Trabeculectomy: A Case Report

doi:10.4236/ojoph.2013.33018

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Open Journal of Ophthalmology, 2013, 3, 73-75

http://dx.doi.org/10.4236/ojoph.2013.33018 Published Online August 2013 (http://www.scirp.org/journal/ojoph) 73

Necrotizing Scleritis Associated with 5-Fluorouracil and

Sub-Tenon’s Block in Patient with Previous

Trabeculectomy: A Case Report

Tuan A. Tran1*, Jeremy O’Connor2, Xavier Fagan3, Tu Tran2, Dan Nguyen2

1Department of Politecnico Ophthalmology, Sydney Eye Hospital , Sydney, Austra lia; 2Department of Glaucoma, Victorian Eye and

Ear Hospital, Melbourne, Australia; 3Department of Medical Ophthalmology, Victorian Eye and Ear Hospital, Melbourne, Australia.

Email: *[email protected]

Received April 24th, 2013; revised May 30th, 2013; accepted June 17th, 2013

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Necrotizing scleritis is the most severe form of scleritis with a significant threat to vision and globe integrity. It can be

infectious, surgically induced necrotizing scleritis (SINS) or systemic autoimmune associated. We report a case of ne-

crotizing scleritis associated with 5-fluorouracil (5-FU) at the site of sub tenon’s block in a patient with previous trabe-

culectomy. To our knowledge, this is the first reported case of necro tizing scleritis associated with 5-FU. This may im-

plicate alternative approaches to local anaesthetic techniques when using adjunctive 5-FU.

Keywords: Necrotizing Scleritis; 5-Fluorouracil; Sub-Tenon’s Block; Glaucoma

1. Case Report

A 74-year-old man with a 43-year history of primary

open angle glaucoma (POAG) had recent bilateral

trabeculectomies with Mitomycin C (MMC) (0.2 mg/ml

for 3 minutes). Regular reviews demonstrated well func-

tioning blebs and each trabeculectomy was followed up

with three sub-conjunctival 5-FU injections. Medical

history included non-insulin dependent diabetes.

He subsequently developed a right eye cataract and

underwent routine phacoemulsification and intraocular

lens insertion with a temporal clear corn eal wound. Peri-

operative sub-conjunctival 5-FU (5 mg/0.1ml) was in-

jected in the superior fornix above the bleb to minimise

bleb fibrosis. The operation was performed with a sub-

Tenon’s block through an inferonasal conjunctival inci-

sion with 4 ml of lignocaine 2%.

On day one post-operative review, visual acuity with

pinhole (VA-PH) was 6/12 (20/40), intraocular pressure

(IOP) was 12 mmHg and examination was otherwise

unremarkable. He was started on two hourly topical

Prednisolone Acetate 1% and Phenylephrine Hydroch-

loride 0.12% (Prednefrin Forte 1%, Allergan Aust. Pty

Ltd) and four times daily chloramphenicol 0.5%.

On week one post-operative review, significant pain

was noted. Examination revealed VA-PH reduced to 6/18

(20/60), IOP was 14 mmHg. At the site of sub-Tenon’s

block, there was a localised lesion of episcleritis with a

focal area of avascular sclera. No further 5-FU was given

and he was commenced on oral Ibuprofen 400 mg three

times a day.

The following week, VA-PH was 6/12 (20/40), IOP

remained at 14 mmHg and the non-healing conjunctival

defect persisted. There was significant pain preventing

the patient from sleep, which instigated surg ical debride-

ment under peribulbar block. Swabs were taken for

microscopy and culture whilst debrided conjunctival and

Tenon’s tissue were sent for histopathology. Due to a

possible infective cause the conjunctival defect was not

closed.

One week post-debridement, pain persisted accompa-

nied with a reduction in VA to 6/36 (20/120) whilst IOP

was 10 mmHg. The area of avascular sclera increased in

size, measuring 5.2 mm × 4.0 mm Figure 1. C ultures

showed no growths while histology demonstrated non-

specific inflammation and no fungal elements.

He was admitted for further investigations and treat-

ment. Vasculitic, autoimmune, treponemal/syphilis and

TB tests were negative. A second debridement was per-

formed. Repeat conjunctival, episcleral and scleral bio-

psies demonstrated unremarkable cultures and histology

*Corresponding a uthor.

Necrotizing Scleritis Associated with 5-Fluorouracil and Sub-Tenon’s Block in Patient with Previous

Trabeculectomy: A Case Report

Figure 1. Necrotizing scleritis at site of sub-tenon’s block

three weeks post cataract and one week after initial de-

bridement (note lack of sloughing at base). Area measuring

5.2 mm × 4.0 mm.

once again.

He was commenced on intensive topical Prednefrin

Forte, high dose oral Prednisolone (75 mg daily) and

intravenous Ceftriaxone (1 g daily). Given the results of

all these investigations; the provisional diagnosis was

necrotizing scleritis secondary to 5-FU in the setting of

sub-Tenon’s block.

Despite intensive treatment for one week, there was

progression of thinning and avascular scleral area (6 mm

× 4.0 mm) Figure 2. In view of worsening diabetic

control, oral steroids were promptly weaned. The scleritis

only showed resolution once a contralateral conjunctival

graft was successfully implanted 6 weeks post-cataract

surgery to close the persistent epithelial defect Figure 3.

2. Discussion

Necrotizing scleritis is characterized by severe pain with

areas of capillary closure producing a porcelain white

sclera or a violaceous discolouration due to thinning and

underlyi ng uveal expos ure .

The main causes are infectious, systemic autoimmune

associated and Surgically Induced Necrotizing Scleritis

(SINS). SINS typically involves the site of surgery, has

an association with underlying systemic autoimmune

diseases and time of onset is nine months on average [1].

This case is unlikely due to any of these causes due to

negative cultures, serology (including autoantibodies),

rapid onset of scleritis and distant location of phaco emul-

sification wounds relative to the area of scleritis.

Systemic autoimmune diseases have high association

with necrotizing scleritis, particularly Rheumatoid Arth-

ritis and other ANCA associated vasculitides [1]. It has

been reported that necrotizing scleritis is the type most

associated with systemic disease (80%) [2], while 92%

have evidence of systemic disease upon of presentation

of scleritis [3].

Figure 2. Despite one week of high-dose oral prednisolone

there was continuing progression with further thinning and

increase in size to 6 mm × 4.0 mm.

Figure 3. Resolution by conjunctival graft performed 6

weeks after sub-tenon’s block and adjace nt 5-fluor our acil.

Antimetabolites, predominantly MMC, have been at-

tributed to post-operative necrotizing scleritis, however

none to our knowledge have been reported with 5-FU.

5-FU is a pyrimidine analogue with several cytotoxic

effects useful in promoting apoptosis of Tenon’s capsule

fibroblasts therefore preventing excessive scarring in

primary filtration surgery [4].

Although exact mechanisms of the inciting injury are

unclear, we hypothesize the process of the necrotizing

scleritis may be due to tracking of 5-FU inferiorly after

injection and pooling in the area of conjunctival/Tenon

defect. Non-healing conjunctival epithelium is said to be

a risk factor of necrotizing scleritis [5]. In our case, the

overlying tissue from the sub-Tenon’s block never healed.

We believe this is unlikely due to the lignocaine and is

more likely due to the inhibition of healing from adjacent

5-FU. Furthermore, th e lack of overlyin g conjun ctiva and

Tenon’s prolonged and exacerbated the scleritis through

attenuation of scleral healing.

To our knowledge, this is the fir st reported case of ne-

crotizing scleritis within the immediate post-operative

phase relating to 5-FU and sub-Tenon’s blocks. This may

Necrotizing Scleritis Associated with 5-Fluorouracil and Sub-Tenon’s Block in Patient with Previous

Trabeculectomy: A Case Report

implicate alternative approaches to local anaesthetic in

patients with concurrent 5-FU in patients with previous

trabeculectomy.

REFERENCES

[1] D. Wakefield, N. Di Girolamo, S. Thurau, G. Wildner and

P. McCluskey, “Scleritis: Immunopathogenesis and Mo-

lecular Basis for Therapy,” Progress in Retinal and Eye

Research, Vol. 35, 2013, pp. 44-62.

doi:10.1016/j.preteyeres.2013.02.004

[2] M. Sainz de la Maza, N. Molina, L. A. Gonzalez-Gon-

zalez, P. P. Doctor, J. Tauber and C. S. Foster, “Clinical

Characteristics of a Large Cohort of Patients with Scleri-

tis and Episcleritis,” Ophthalmology, Vol. 119, No. 1.

2012, pp. 43-50. doi:10.1016/j.ophtha.2011.07.013

[3] E. K. Akpek, J. E. Thorne, F. A. Qazi, D. V. Do and D. A.

Jabs, “Evaluation of Patients with Scleritis for Systemic

Disease,” Ophthalmology, Vol. 111, No. 3, 2004, pp.

501-506. doi:10.1016/j.ophtha.2003.06.006

[4] L. M. Abraham, D. Selva, R. Casson and I. Leibovitch,

“The Clinical Applications of Fluorouracil in Ophthalmic

Practice,” Drugs, Vol. 67, No. 2, 2007, pp. 237-255.

doi:10.2165/00003495-200767020-00005

[5] R. R. Doshi, G. J. Harocopos, I. R. Schwab and E. T.

Cunningham Jr., “The Spectrum of Postoperative Scleral

Necrosis,” Survey of Ophthalmology, 2013. (in Press)

doi:10.1016/j.survophthal.2012.11.002