Multimodal Imaging of Nodular Posterior Scleritis: Case Report and Review of the Literature

Abstract

Nodular posterior scleritis represents a small percentage of all cases of posterior scleritis. Because of the scarcity of nodular posterior scleritis, it may be confused or even misdiagnosed as an intraocular tumor or posterior uveitis. Here, we are reporting a case of nodular posterior scleritis in a 25-year-old medically free male. Furthermore, we reviewed previously reported cases of nodular posterior scleritis. Our patient presented with a choroidal mass of about one disc diameter in size. In addition, the patient had exudative retinal detachment and chorioretinal folds. B scan ultrasonography showed subretinal fluid, macular nodular thickening and underlying echolucent area along with medium internal reflectivity on A scan. Fluorescein angiography revealed early pinpoint areas of hyperfluorescence and late pooling under the detached retina. Indocyanine green angiography demonstrated early diffuse hypofluorescence corresponding to the area of detachment and late multiple pinpoint spots of hyperfluorescence. After intravenous methylprednisolone 1 g for 3 days followed by a course of oral prednisolone along with mycophenolate mofetil, the patient experienced rapid recovery with improvement in vision and complete resolution of subretinal fluid. On further follow-up, the patient regained 20/20 vision. Nodular posterior scleritis is a rare unilateral disease with strong female predominance. Multimodal imaging should be employed to confirm the diagnosis. The disease must be diagnosed correctly to avoid any unnecessary diagnostic work-up and aggressive management. Most cases carry excellent prognosis with no recurrence.

Introduction

Posterior scleritis is inflammation of the sclera posterior to the equator.[1] Posterior scleritis may be classified into diffuse posterior scleritis or rarely nodular posterior scleritis.[2,3] The diffuse form causes generalized increased eye wall thickness, while the nodular subtype causes a scleral nodule. The latter usually causes an amelanotic subretinal mass, with adjacent subretinal fluid and chorioretinal folds. Because of the scarcity of nodular posterior scleritis, it may be confused or even misdiagnosed as an intraocular tumor or posterior uveitis. Misdiagnosis may lead to aggressive treatment methods such as with radiotherapy or chemotherapy. One of the cases reported had been misdiagnosed as choroidal melanoma and was referred for enucleation.[4] Shields et al. reported that posterior scleritis represented 1.5% of 400 lesions mimicking choroidal melanoma.[5] Up to 29% of all cases of posterior scleritis are associated with other autoimmune diseases such as rheumatoid arthritis (9%), granulomatosis with polyangiitis (4%), and systemic vasculitis (4%).[3] B-scan ultrasonography may show nodular scleral thickening with fluid in Tenon's space. In this paper, we are reporting a case of nodular posterior scleritis and summarizing previously reported cases.

Case Report

A 25-year-old male, otherwise medically free, presented with pain, redness, and decreased vision in the left eye for 2 days. He was given elsewhere topical prednisolone acetate and diclofenac with no improvement. At presentation, visual acuity was counting fingers at one foot. Extraocular motility was limited in all gazes. He had severe conjunctival chemosis with a deep and quiet anterior chamber. On fundus examination, an amelanotic choroidal mass of about one disc diameter in size located inferotemporal to the disc was found. In addition, there was exudative retinal detachment (ERD) involving the macula [Figure 1a].

Figure 1.

Fundus photograph illustrating a subretinal mass located at the inferior part of the macula. Exudative retinal detachment and chorioretinal folds are seen in the macula (a). Optical coherence tomography showing choroidal thickening with subretinal fluid and hyperreflective fibrinous material (b). B-scan ultrasonography showing surbretinal fluid and nodular thickening at the macula with underlying echolucent area (c). A-scan ultrasonography showing medium internal reflectivity (d)

Optical coherence tomography (OCT) examination revealed multifocal ERD with increased choroidal thickening [Figure 1b]. B-scan ultrasonography revealed subretinal fluid and hyperechogenic nodular scleral thickening with underlying diffuse edema in Tenon's space [Figure 1c]. Extraocular muscles were normal and not involved on ultrasonography. The lesion showed medium internal reflectivity on A-scan ultrasonography [Figure 1d]. Fundus fluorescein angiography (FFA) showed early pinpoint areas of hyperfluorescence along with late pooling of dye under the detached retina [Figure 2a-c]. Indocyanine green angiography (ICGA) revealed diffuse hypofluorescence corresponding to the area of ERD in the early phase with multiple pinpoint hyperfluorescence in the late phases [Figure 2d-e]. Computerized tomography (CT) scan of the orbit with contrast demonstrated scleral thickening [Figure 2f].

Figure 2.

Fluorescein angiography demonstrating multiple areas of pinpoint leakage (a and b) and diffuse pooling at the area of the exudative retinal detachment (c). Indocyanine green angiography showing an area of early hypofluorescence at the location of the detached retina (d) and areas of pinpoint hyperfluorescence during late phases (e). Computerized tomography showing scleral thickening (f)

Systemic workup including antinuclear antibodies, antidouble-stranded DNA, antineutrophilic cytoplasmic antibodies, rheumatoid factor, IgG4, angiotensin-converting enzyme serum lysozyme, tuberculin skin test, syphilis serology, and CT chest was all unremarkable. The patient had a mildly elevated erythrocyte sedimentation rate and C-reactive protein.

The patient received intravenous methylprednisolone 1 g for 3 days, followed by a combination of a course of oral prednisolone (1 mg/kg/day) along with mycophenolate mofetil 1 g twice a day as a steroid-sparing agent. The patient experienced rapid improvement in vision. One month after starting treatment, visual acuity improved to 20/20, and OCT examination revealed the complete resolution of subretinal fluid [Figure 3]. Moreover, there was no recurrence over 6 months.

Figure 3.

Fundus image demonstrating complete resolution of the subretinal mass and exudative retinal detachment (a). Optical coherence tomography image illustrating complete resolution of subretinal fluid after treatment (b)

Discussion

On review of the literature, the mean age at diagnosis was 52 years. Nodular posterior scleritis is a unilateral disease with strong female predominance. Most cases reported did not have any systemic association. The most common presenting symptom was pain and decreased vision. Presenting visual acuity ranged from 20/20 to 20/200. About half of the cases reported in the literature did not have any anterior segment inflammation. Similarly, McCluskey et al. reported that anterior segment involvement is seen in 60% of posterior scleritis cases.[3] The most common clinical features reported were amelanotic subretinal mass, ERD, and chorioretinal folds. While disc swelling was a common sign of diffuse posterior scleritis, it was only reported in two nodular posterior scleritis cases.[6,7] The differential diagnosis of amelanotic subretinal mass includes amelanotic melanoma, choroidal granuloma, choroidal hemangioma, and choroidal osteoma.[8] Clinical features used to distinguish nodular posterior scleritis from choroidal melanoma include the presence of pain, conjunctival injection, chemosis, limited extraocular motility, and choroidal folds. Cases with normal anterior segment represent a diagnostic challenge as they closely resemble choroidal melanoma.

FFA is an important assessment tool distinguishing nodular posterior scleritis from choroidal melanoma. FFA findings in our case were consistent with what has been reported in the literature. The most common FFA finding was multiple pinpoint areas of leakage and pooling of dye consistent with subretinal fluid. ICGA in our case confirms that posterior scleritis may cause major alteration in the choroid. It showed early diffuse hypofluorescence corresponding to the ERD, which is possibly due to choroidal perfusion defect. Moreover, there was pinpoint hyperfluorescence seen in intermediate and late stages. This most likely represents choroidal inflammation and leakage from the large choroidal vessels. This pattern is seen in acute uveitis associated with Vogt-Koyanagi-Harada disease.[9] ICGA findings of nodular posterior scleritis were rarely reported in the literature. The ICGA pattern in our case is similar to what has been reported by Liu.[10] OCT typically shows choroidal mass, subretinal fluid, and choroidal folds. The most common finding on B-scan ultrasonography was an acoustically solid scleral mass with adjacent echolucent area representing scleral edema. Most cases showed medium-to-high internal reflectivity.[4,6,7,11,12,13]

The prognosis of nodular posterior scleritis is excellent. There was no recurrence in the cases reported in the literature. Most showed complete resolution of the mass and subretinal fluid with improvement in vision to 20/30 or better [Table 1]. Similarly, our patient achieved a visual acuity of 20/20. Most cases responded well to systemic steroids [Table 2]. One case showed no response to steroids.[13] Besides systemic steroids, one case was treated with mycophenolate mofetil.[20] In our case, steroids achieved rapid remission of the disease. We added mycophenolate mofetil to steroids to spare the patient from systemic steroids. The choice of mycophenolate mofetil was based on its safety profile and efficacy in the treatment of noninfectious ocular inflammatory diseases.[23]

Table 1.

Literature review of patients with posterior nodular scleritis: Demographics and historical findings

Study	Age	Gender	Laterality	Systemic work up	Initial VA	Final VA
Current case, 2020	25	Male	Unilateral	Negative	CF 1 foot	20/20
Shibata, 2019[14]	59	Female	Unilateral	Hepatitis B	20/200	N/A
Alsharif, 2018[15]	30	Male	Unilateral	Negative	20/200	N/A
Agrawal, 2016*[16]	57	Female (82%)	Unilateral (100%)	Negative (55%)	20/105	N/A
Sin, 2016[17]	42	Female	Unilateral	SLE	N/A	N/A
Ozkaya, 2015[18]	41	Female	Unilateral	Negative	20/50	N/A
Liu, 2015[10]	42	Female	Unilateral	Negative	N/A	N/A
Hage, 2011(Case 1)[19]	38	Female	Unilateral	Negative	20/80	N/A
Hage, et al., 2011 (Case 2)[19]	52	Female	Unilateral	Negative	20/200	N/A
Hatef, 2010[20]	55	Female	Unilateral	Negative	20/40	20/20
Perez-Campagne, 2007[21]	30	Male	Unilateral	Sarcoidosis	20/25	20/20
Sridharan, 2007[11]	53	Female	Unilateral	Negative	20/20	20/20
Shukla, 2006[12]	45	Female	Unilateral	Negative	17/200	20/20
Arevalo, 2003[13]	37	Female	Unilateral	Negative	20/60	N/A
Wang, 2003[6]	40	Female	Unilateral	Negative	20/30	20/20
Demirci, 2000[22]	41	Female	Unilateral	Negative	20/20	20/20
Brod, 1990[7]	70	Female	Unilateral	Negative	20/200	20/30
Finger, 1990[4]	66	Male	Unilateral	Negative	20/200	N/A

*The mean age and visual acuity of the cases reported by Agrawal et al. was documented in the table. N/A: Information not available, ERD: Exudative retinal detachment, SLE: Systemic lupus erythematosus

Table 2.

Treatment modalities and outcome of patients with posterior nodular scleritis

Study	Management	Outcome
Current case, 2020	IV steroid followed by oral steroids and mycophenolate mofetil	Resolution
Shibata, 2019[14]	Oral prednisolone (20 mg)	Resolution
Alsharif, 2018[15]	Trans-septal periocular triamcinolone acetonide (40 mg/ml)	Resolution
Sin, 2016[17]	IV methylprednisolone 1 g for 3 days followed by oral prednisolone (5 mg) and HCQ (200 mg)	Resolution
Ozkaya, 2015[18]	Topical & oral NSAIDs	Resolution
Liu, 2015[10]	Oral indomethacin (25 mg)	Resolution
Hage, 2011 (Case 1)[19]	Oral prednisolone	Resolution
Hage, 2011 (Case 2)[19]	Topical NSAID	Resolution
Hatef, 2010[20]	IV Steroid 1 gram for 3 days followed by oral prednisolone 60 mg and mycophenolate mofetil	Resolution
Perez-Campagne, 2007[21]	Systemic steroid administration (1 mg/kg)	Resolution
Sridharan, 2007[11]	Prednisolone 60 mg tapering over 6 weeks	Resolution
Shukla, 2006[12]	Prednisolone 1 mg/kg/day tapered over 2 months	Resolution
Arevalo, 2003[13]	Oral prednisolone	No response
Wang, 2003[6]	Oral prednisolone and diclofenac	Resolution
Demirci, 2000[22]	Observation	No change
Brod, 1990[7]	Systemic steroids	Resolution
Finger, 1990[4]	Enucleation

IV: Intravenous, HCQ: Hydroxychloroquine, NSAID: Nonsteroidal antinflammatory drugs

Conclusion

Nodular posterior scleritis is a rare unilateral disease, which may mimic an intraocular tumor. It predominantly affects females. It causes a yellow subretinal mass, ERD, and chorioretinal folds. Multimodal imaging including OCT, FFA, ICGA, ultrasonography, and CT orbit should be employed to confirm the diagnosis. The disease must be diagnosed correctly to avoid any unnecessary diagnostic workup and aggressive management. Most cases carry excellent prognosis with no recurrence.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.