Diffuse anterior scleritis following micropulse transscleral laser: A case report

Archana Nivash; Sujatha Mohan; Niranjana Anand; Murali Ariga

doi:10.4103/ijo.IJO_1869_22

CASE REPORT

Year : 2023 | Volume : 3 | Issue : 1 | Page : 80-82

Diffuse anterior scleritis following micropulse transscleral laser: A case report

Archana Nivash¹, Sujatha Mohan², Niranjana Anand¹, Murali Ariga³
¹ Glaucoma Services, Rajan Eye Care Hospital Pvt Ltd, Chennai, Tamil Nadu, India
² Head of Glaucoma Department, Associate Medical Director, Rajan Eye Care Hospital, Chennai, Tamil Nadu, India
³ Head of Glaucoma Department, Medical Director, Swamy Eye Clinic, Chennai, Tamil Nadu, India

Date of Submission	30-Jul-2022
Date of Acceptance	09-Nov-2022
Date of Web Publication	20-Jan-2023

Correspondence Address:
Archana Nivash
Consultant, Glaucoma Services, Rajan Eye Care Hospital Pvt Ltd, No. 5, Vidyodaya 2^nd Street, T Nagar, Chennai - 600 017
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijo.IJO_1869_22

Abstract

We report a case of scleritis following micropulse transscleral laser therapy (TLT) in an elderly female with medically uncontrolled primary open-angle glaucoma. She had completed antitubercular treatment (ATT) for pulmonary tuberculosis 20 years ago. Along with scleritis, there were vitritis and macular edema post laser. Systemic blood investigations for connective tissue disorders were negative. She had latent tuberculous infection with positive Mantoux test and quantiferon TB gold. She responded favorably to topical steroids with no vision loss. Though TLT, with its pulsed laser delivery, is considered safe, caution must be exercised in patients susceptible to inflammation.

Keywords: Latent tuberculosis, micropulse Cyclo G6, scleritis

How to cite this article:
Nivash A, Mohan S, Anand N, Ariga M. Diffuse anterior scleritis following micropulse transscleral laser: A case report. Indian J Ophthalmol Case Rep 2023;3:80-2

How to cite this URL:
Nivash A, Mohan S, Anand N, Ariga M. Diffuse anterior scleritis following micropulse transscleral laser: A case report. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Mar 27];3:80-2. Available from: https://www.ijoreports.in/text.asp?2023/3/1/80/368184

Micropulse transscleral diode laser therapy (TLT) or Cyclo G6 has been in use since 2010.^[1] It differs from continuous wave diode cyclophotocoagulation by having a duty cycle with on and off time, allowing tissues to cool down between pulses, causing less collateral damage.^[2] Complications like hypotony, phthisis bulbi, sympathetic ophthalmia, and others are rare. Hence, TLT can be performed in eyes with good vision and less chance of inflammation.^[3] We report a case of scleritis, 2 months following micropulse TLT.

Case Report

A 76-year-old hypertensive female, diagnosed with glaucoma, was on three topical medications (combination of timolol 0.5% and brinzolamide 1% BD, bimatoprost 0.01%, netarsudil 0.02%.) She presented with complaints of blurred vision. Her best corrected visual acuity (BCVA) was 6/6 N6 in both eyes. She was pseudophakic in both eyes. There were no areas of scleral thinning. Her intraocular pressure (IOP) in the right eye (RE) was 24 mmHg and in the left eye (LE) was 18 mmHg. Gonioscopy showed open angles with grade 3 trabecular pigmentation. Fundus examination showed a cup disk ratio of 0.9 in RE and 0.7 in LE [Figure 1]a and [Figure 1]b. Humphrey visual fields 24-2 in RE showed biarcuate defect involving fixation with mean deviation (MD) -26.18, while LE showed incomplete inferior arcuate defect with MD -3.15. OCT macula shows epiretinal membrane in RE and was normal in LE [Figure 1]c and [Figure 1]d. As the patient was unwilling to undergo trabeculectomy, TLT was done in RE under peribulbar anesthesia with Cyclo G6 (IRIDEX Laser Systems, Iris Medical Instruments, Mountain View, CA, USA) using the new MP3 probe with a duty cycle of 31%. The procedure was done with power of 2500 mW for 80 s per hemisphere with a continuous sweeping motion with firm pressure under viscoelastic cover for a smooth sweep. Also, 3 o' clock and 9 o' clock hours were avoided.

Figure 1: (a) Fundus photograph of the right eye shows a cup disk ratio of 0.9 and pallor with absent foveal reflex. (b) Fundus photograph of the left eye shows average-sized disk with a cup disk ratio of 0.7. (c) OCT of macula shows epiretinal membrane in the right eye. (d) Normal foveal contour in the left eye. OCT = optical coherence tomography

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She was prescribed topical 1% prednisolone acetate four times daily with one weekly taper for 4 weeks; cycloplegics and her topical antiglaucoma medications were continued. Postoperatively, there was no iritis or scleral congestion. Her IOP at 1 month was 16 mmHg on three antiglaucoma medications. RE visual field was stable. Eight weeks following laser, she presented with sudden-onset redness, pain, and blurred vision. BCVA was 6/6p. IOP was 26 mmHg on medications. After application of phenylephrine, there was grade 1 scleritis with mild dilatation of deep episcleral vessels and tenderness [Figure 2]a.^[4]

Figure 2: (a) Slit-lamp photo of the right eye showing grade 1 scleritis with mild dilatation of deep episcleral vessels after application of topical phenylephrine. (b) Slit-lamp photo of the right eye at 1 month posttreatment showing resolved scleritis

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RE fundus exam revealed mild vitreous haze. OCT macula revealed epiretinal membrane with spongy macular edema in RE [Figure 3]a. Posterior sclera was normal on B scan. She was treated with prednisolone acetate 1% eye drops six times daily and weekly taper and nepafenac 0.1% eye drops and oral acetazolamide 250 mg twice daily. Blood investigations including rapid plasma reagin (RPR), antinuclear antibody (ANA), cytoplasmic and perinuclear antineutrophilic cytoplasmic antibody (cANCA and pANCA, respectively), and rheumatoid factor (RF) factor were negative. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were within normal limits. Mantoux test was positive with 30 × 30 mm induration. Quantiferon TB gold was positive.

Figure 3: (a) OCT macula right eye shows epiretinal membrane with spongy macular edema with loss of foveal contour after micropulse laser. (b) OCT macula right eye shows reduced macular edema at 1 month posttreatment. OCT = optical coherence tomography

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Computed tomography (CT) chest revealed fibrosis of both lungs with no evidence of active infection and no lymphadenopathy. In view of no active infection, no antitubercular therapy was initiated. One month following the onset of scleritis, her inflammation subsided with reduction of macular edema [Figure 2]b and [Figure 3]b. Her BCVA was 6/6. Her IOP was 21 mmHg with topical antiglaucoma medications. She is under close follow-up. After resolution of inflammation, surgical intervention might be warranted if IOP remains high and progression is documented.

Discussion

Micropulse TLT has been connoted to have superior safety profile in comparison to the traditional diode cyclophotocoagulation due to delivery of the laser in a pulsed manner with on and longer off cycles. Hence, it has been used safely in eyes with various types and severity of glaucoma.^[5]

However, complications reported include decline in BCVA, surface keratopathy, persistent mydriasis, hyphema, hypotony, macular edema, and choroidal effusion.^[2] A case of intermediate uveitis has been reported in an African female.^[6] Till date, there has been no report of scleritis. The energy used in our patient was well within the recommended range.^[7]

Scleritis is known to occur when there is a disturbance in the equilibrium of scleral antigens to collagen and glycosaminoglycans in the sclera. It is mediated by a type 4 delayed hypersensitivity reaction.^[8]

Absence of scleral nodules and active focus of infection elsewhere in the body are against infective cause for the scleritis. Our patient gave history of pulmonary tuberculosis 20 years ago and had completed her course of antitubercular treatment (ATT). This might be responsible for the positive tests.^[9] There is no clear evidence regarding this acting as a risk factor for scleritis, which, however, has the same underlying mechanism. The inflammation associated with the laser might have acted as a trigger. It is crucial to rule out autoimmune diseases in order to decide on the route and dosage of steroid therapy and prognosticate scleritis.^[10] Our patient tested negative for the same. ATT in this scenario was deferred after consulting a pulmonologist. She responded favorably to topical steroids and is under close follow-up. Further follow-up of our patient will give us a clearer insight into the exact etiology of her scleral inflammation.

Conclusion

While inflammation is the rule with continuous wave diode cyclophotocoagulation, its incidence is much less with micropulse. However, in eyes predisposed to inflammation, micropulse laser can cause scleritis.

Acknowledgement

Mr. Leo John is acknowledged for his technical help with the images.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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