toxic anterior segment syndrome after uncomplicated cataract surgery

1. TOXIC ANTERIOR SEGMENTSYNDROME AFTER UNCOMPLICATEDCATARACT SURGERY Kadir Eltutar*, M.D., Burak Bilgin**, M.D., N. Demet Ozcelik*, M.D.

2. PURPOSE : To evaluate the anterior segment examination findings and the response to medical therapy of patients who had toxic anterior segment syndrome (TASS) after uncomplicated cataract surgery.

3. METHODS : Fourteen eyes of 14 patients were enrolled. Best corrected visual acuity ( BCVA ), biomicroscopic anterior segment examination, intraocular pressure measurement ( IOP ) and fundus examination were performed to assess TASS occuring during post-operative 12- 48 hours after uncomplicated phacoemulsification surgery. Mean follow-up time: 2,2 ± 0,35 months. Mean age: 64,07 ± 5,40 years. Visual impairment, corneal edema, tyndalisation, fibrin formation, hypopyon, vitritis and response to steroid therapy were evaluated prospectively.

4. METHODS : Pupilla was dilated with tropicamide 1% and cyclopentolate 1% before surgery. Operations were performed under sub-tenon anesthesia achieved by prilocaine 2 %. Antisepsis of the lids, eye lashes and conjunctiva was achieved by povidone-iodine 5 % before the procedure . BSS plus containing 0.05 mg/ 500 cc ( 1:10000 ) epinephrine was used as infusion fluid. The procedure was ended with intracameral cefuroxime axetile injection for infection prophylaxy. Postoperative topical steroid drops ( prednisolone acetate 1 % ) were instilled every hour in combination with topical antibiotics ( ofloxacin ) and mydriatics t.i.d., with gradual tapering.

5. RESULTS : After topical steroid therapy lasting for one week, the visual acuity improved in 11 ( 78,57 % ) eyes . No significant visual improvement occurred in 3 ( 21,42 % ) eyes. Significant corneal edema was found in 4 ( 28,57 % ) and mild corneal edema was observed in the other 10 ( 71,42 % ) eyes. Fibrin reaction occurred in 5 ( 35,71 % ) eyes and tyndalisation in various degrees was positive in all eyes. There was 1 mm hypopyon in 1 ( 7,14 % ) patient. There was no sign of vitritis and steroid therapy was effective in all of the patients. In addition to topical treatment with steroids, mydriatics and antibiotic drops; systemic and subconjunctival steroids were used in 3 ( 21,42 % ) patients who had fibrin formation and in one patient who had hypopyon ( 7,14 % ) .

6. RESULTS : The samples collected from the patients were Gram-stain and culture negative. None of our patients had severe visual loss, permanent corneal edema or glaucoma. No specific causative agent or a predisposing factor was detected in our cases.

9. CONCLUSIONS : After uncomplicated cataract surgery, toxic anterior segment may occur in early postoperative period, which is treated succesfully with steroids. Throughout the literature search gathered about the outbreaks and single cases; there was no significant data to suggest a single factor was responsible in the etiopathogenesis of TASS. Cleaning and sterilisation of intraocular instruments may be considered as the most important factor between multiple potential risk factors related to TASS. The outcomes of topical steroid drops and close monitoring in the management of TASS are excellent, as reported in many cases and so as in our series.

10. The possible factors of anterior segment toxicity are; Inproper concentration of intracameral antibiotics, toxicity of intracameral medications containing preservatives or additives, Retained cortex, Prolonged surgery, Reusable cannulated instruments, reusable inserters of intraocular lenses or I/A tips, Excessive iris manipulation with the metal instruments, Metal ion residues, residues of denaturated OVD or debris due to inadequate rinsing, Hemorrhage of limbal vessels that is entering from the clear corneal incision, Hypersensitivity to any of the materials or solutions used, immunologic differences and, Instruments with inappropriately dried lumens.

11. CONCLUSIONS : Though response to steroid therapy is excellent, it should be kept in mind that severe complications like irreversible visual loss, permanent endothelial damage , corneal decompensation, permanently dilated pupil, cystoid macular edema or glaucoma due to permanent damage to trabecular meshwork may occur after TASS .

12. CONCLUSIONS : As cataract surgery is the most common procedure applied to older population, TASS should be considered as one of the most important complications of the procedure and treated strictly . If there is any doubt about the differential diagnosis, unless proven, the patient should be treated as having infectious endophthalmitis as both conditions may be presented similarly in early stages. More studies have to be done to understand the multifactorial risk factors affecting the etiopathogenesis of this syndrome.