Diode Laser Transscleral Cyclophotocoagulation

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Diode Laser Transscleral CyclophotocoagulationInduced Staphyloma Following Trabeculectomy With Mitomycin C Tiago S. Prata, MD Verônica C. Lima, MD Luciano M. Pinto, MD Elaine F. Costa, MD Luiz Alberto S. Melo, Jr., MD ABSTRACT

A 42-year-old man developed progressive scleral iatrogenic staphyloma in the region of a previous trabeculectomy with mitomycin C after three sessions of diode laser transscleral cyclophotocoagulation for a refractory glaucoma secondary to trauma. After clinical and laboratory evaluations, no signs of systemic or autoimmune disorders were found. The patient underwent a reinforcement of the eye wall with a scleral patch over the staphyloma area and a glaucoma drainage device was implanted. Repeated transscleral cyclophotocoagulation procedures should be performed cautiously in patients who have had previous trabeculectomy. [Ophthalmic Surg Lasers Imaging 2008;39:343-345.] INTRODUCTION

Staphyloma is an uncommon, serious ocular lesion consisting of scleral thinning where the underlying uveal tissue bulges to form a raised pigmented lesion in the eye wall.1,2 Ocular staphyloma has been described From the Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil. Accepted for publication November 20, 2007. Address correspondence to Tiago S. Prata, MD, Al. Campinas, 1232/71 São Paulo – SP – Brazil.

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in association with different ocular and systemic conditions, such as high axial myopia,3 ocular sarcoidosis,4 and autoimmune diseases.2 Few reports of staphyloma following antiglaucomatous procedures have been published after either diode laser transscleral cyclophotocoagulation2,5 or trabeculectomy with mitomycin C (MMC).6,7 We describe a patient who developed a progressive scleral iatrogenic staphyloma following both procedures. CASE REPORT

A 42-year-old man developed glaucoma in his left eye due to a perforating ocular trauma 8 years earlier. The best-corrected visual acuity (BCVA) was counting fingers at 30 cm and the intraocular pressure (IOP) was 40 mm Hg with timolol maleate 0.5% (Alcon Laboratories, São Paulo, Brazil). Biomicroscopy examination disclosed corneal opacities and neovascularization, aphakia, and anterior synechiae. Gonioscopy revealed a narrow angle and extensive synechiae. The retina had no alterations and a glaucomatous optic nerve head was observed. The fellow eye had no alterations. Brinzolamide hydrochloride 1% (Azopt; Alcon Laboratories) and brimonidine tartrate 0.2% (Alcon Laboratories) were added and the IOP decreased to 30 mm Hg. A superior nasal trabeculectomy with MMC (0.3 mg/mL) was performed with no complications. The postoperative IOP varied between 8 and 16 mm Hg. After 8 months, the patient presented with severe ocular pain and the IOP was 44 mm Hg. A glaucoma drainage implant was not available and a trabeculectomy was not performed because of extensive goniosynechiae in the superotemporal region. A 180° diode laser transscleral cyclophotocoagulation was done. The diode laser transscleral cyclophotocoagulation procedure was repeated on two occasions within a 1-year interval to reduce the IOP. Six months after the last diode laser transscleral cyclophotocoagulation treatment, the patient complained

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Figure. (A) Staphyloma at the site of the previous trabeculectomy in the superonasal area. (B) Staphyloma progression 1 month and (C) 3 months after the reinforcement of the eye wall with a scleral patch.

of severe ocular pain and redness. Scleral thinning with uveal prolapse was observed at the surgical site of the trabeculectomy (Fig. 1A). The IOP was 40 mm Hg and there was no anterior chamber inflammatory reaction. After a clinical evaluation, no signs or symptoms of autoimmune disorders were found. Results of chest x-rays, a hemogram, and the blood creatinine level were within normal limits. Results of serologic tests, such as rheumatoid factor, antinuclear antibody, cytoplasmicantineutrophil cytoplasmic antibody, and lupus anticoagulant, were negative. Two months later, the staphyloma progressed (Fig. 1B). The patient underwent a reinforcement of the eye wall with a scleral patch at the staphyloma area and an Ahmed Glaucoma Valve (New World Medical, Inc., Rancho Cucamonga, CA) was implanted in the inferonasal quadrant. Four months after this procedure, the patient had neither ocular pain nor signs of scleral thinning in the area adjacent to the scleral patch (Fig. 1C). The BCVA was hand motions and the IOP was 8 mm Hg without medication. DISCUSSION

We reported a case of iatrogenic staphyloma that developed at the site of the trabeculectomy after repeated diode laser transscleral cyclophotocoagulation. Three factors may have played a role in the development of the staphyloma: trabeculectomy, MMC, and diode laser transscleral cyclophotocoagulation. Although staphyloma is an uncommon complication after trabeculectomy, Spaeth and Rodrigues6 reported a series of four cases in patients with secondary glaucoma. All of their patients underwent an uneventful trabeculectomy without antimetabolite and had high IOP in the early postoperative period. In two patients, the IOP was uncontrolled and the staphyloma

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progressed in the area of the trabeculectomy. One eye had to be enucleated and the other was successfully treated with a scleral patch in a manner similar to our patient. The use of MMC is another possible factor for the scleral thinning. Pirouzian et al.7 described a patient with chronic uveitic glaucoma who underwent trabeculectomy in both eyes. The eye treated with adjuvant MMC developed a sclerolimbal ectasia, whereas the other eye did not, which suggests that MMC played a vital role. Previous studies have also reported cases of scleral thinning and staphyloma after pterygium excision with topical MMC.8,9 However, in our report, it is not possible to infer the extent to which the MMC contributed to the scleral thinning because a trabeculectomy was performed simultaneously. Diode laser transscleral cyclophotocoagulation has been used as an effective procedure in refractory glaucomas, but it may cause extensive destruction of the pars plicata and damage to the sclera.2,5,10 Shen et al.2 reported a case of surgically induced necrotizing scleritis and a superior quadrant staphyloma following two sessions of diode laser transscleral cyclophotocoagulation in a patient without previous ocular surgery or confirmed diagnosis of an autoimmune disorder. Those authors proposed two possible explanations for the scleral thinning after diode laser transscleral cyclophotocoagulation. First, the diode laser transscleral cyclophotocoagulation may act as a trigger and the tissue damage may activate the complement pathway, inducing the inflammatory process. Second, the laser itself could be responsible for the scleral thinning.2 Our patient did not present with any autoimmune disorder and the lesion was circumscribed to the previous trabeculectomy area. Therefore, we believe that

OPHTHALMIC SURGERY, LASERS & IMAGING · JULY/AUGUST 2008 · VOL 39, NO 4

diode laser transscleral cyclophotocoagulation contributed directly to the scleral damage and did not act as a trigger. Bhola et al.5 also described a patient with secondary glaucoma who developed a staphyloma in the region of a diode laser transscleral cyclophotocoagulation application. In patients who have undergone MMC-enhanced trabeculectomy, caution should be taken when performing repeated diode laser transscleral cyclophotocoagulation treatments because another potential complication of such a procedure may be an induction of staphyloma in the same quadrant of the previously failed trabeculectomy. Therefore, a thorough informed consent for such patients is paramount and strongly advised. Additionally, a lower concentration of MMC of less than 0.2% may potentially reduce such an adverse reaction. REFERENCES

1. Hardy SP, Lundergan M, Morales L Jr. Ocular staphyloma associated with facial clefting. J Craniofac Surg. 1997;8:326-327. 2. Shen SY, Lai JS, Lam DS. Necrotizing scleritis following diode laser transscleral cyclophotocoagulation. Ophthalmic Surg Lasers Imaging. 2004;35:251-253. 3. Swayne LC, Garfinkle WB, Bennett RH. CT of posterior ocular staphyloma in axial myopia. Neuroradiology. 1984;26:241-243.

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4. Zeiter JH, Bhavsar A, McDermott ML, Siegel MJ. Ocular sarcoidosis manifesting as an anterior staphyloma. Am J Ophthalmol. 1991;112:345-347. 5. Bhola RM, Prasad S, McCormick AG, Rennie IG, Talbot JF, Parsons MA. Pupillary distortion and staphyloma following trans-scleral contact diode laser cyclophotocoagulation: a clinicopathological study of three patients. Eye. 2001;15:453-457. 6. Spaeth GL, Rodrigues MM. Staphyloma as a late complication of trabeculectomy. Ophthalmic Surg. 1977;8:81-85. 7. Pirouzian A, O’Halloran H, Scher C, Jockin Y. Earlyonset scleral and corneal ectasias following low-dose mitomycin-C-augmented trabeculectomy in a uveitic glaucoma patient. Ophthalmologica. 2006;220:406408. 8. Wan Norliza WM, Raihan IS, Azwa JA, Ibrahim M. Scleral melting 16 years after pterygium excision with topical Mitomycin C adjuvant therapy. Cont Lens Anterior Eye. 2006;29:165-167. 9. Tsai YY, Lin JM, Shy JD. Acute scleral thinning after pterygium excision with intraoperative mitomycin C: a case report of scleral dellen after bare sclera technique and review of the literature. Cornea. 2002;21:227-229. 10. McKelvie PA, Walland MJ. Pathology of cyclodiode laser: a series of nine enucleated eyes. Br J Ophthalmol. 2002;86:381-386.

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