Indian Journal of Ophthalmology

BRIEF REPORT
Year
: 2005  |  Volume : 53  |  Issue : 4  |  Page : 272--274

Conjunctival oculosporidiosis with scleral thinning and staphyloma formation


Sheeja Susan John, Shobhana G Mohandas 
 The Department of Ophthalmology, Medical College, Kottayam, Kerala, India

Correspondence Address:
Sheeja Susan John
Department of Ophthalmology, Christian Medical College, Vellore � 632 004, Tamil Nadu
India




How to cite this article:
John SS, Mohandas SG. Conjunctival oculosporidiosis with scleral thinning and staphyloma formation.Indian J Ophthalmol 2005;53:272-274


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John SS, Mohandas SG. Conjunctival oculosporidiosis with scleral thinning and staphyloma formation. Indian J Ophthalmol [serial online] 2005 [cited 2024 Mar 28 ];53:272-274
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?2005/53/4/272/18912


Full Text

Rhinosporidiosis is a chronic granulomatous disease caused by Rhinosporidium seeberi , an endosporulating micro-organism of uncertain taxonomic classification. The disease is endemic in India and Sri Lanka. The most common site of involvement is the nose; the next in frequency are the eye and adnexa.[1] Rhinosporidiosis of the eye and adnexa is termed oculosporidiosis. The mode of transmission remains uncertain although the possibility of water-borne and dust-borne infection has been postulated. Frequent bathing in ponds and lakes filled with stagnant water in endemic areas has been considered a major risk factor.[2] Although the conjunctiva is the most common site of involvement in oculosporidiosis, involvement of the bulbar conjunctiva is relatively uncommon.[3] Cases of scleral melt and staphyloma formation associated with conjunctival oculosporidiosis are relatively rare.[4]

We report two cases of oculosporidiosis of the bulbar conjunctiva associated with scleral thinning and staphyloma formation.

 Case report



Case 1

A 21-year-old male presented with a 3-week history of a dark-coloured swelling and foreign body sensation in the left eye. The patient came from Alleppey District of Kerala, South India, where rhinosporidiosis is endemic. He gave a history of regularly bathing in the local pond, as is the habit of a large proportion of the rural population in Kerala. He was diagnosed 3 years ago to have right anterior nasal rhinosporidiosis, which was surgically treated. Postoperatively, the patient was advised a course of dapsone, which he discontinued 3 months later.

On examination, his presenting visual acuity was 6/6 in the right eye and 6/36 in the left eye improving to 6/6 with spectacles correction (-1.75 Dcyl at 1200sub). The right eye was normal. In the left eye, there was a red fleshy lesion on the left eye bulbar conjunctiva 6 mm from the limbus at the 11 o'clock position. Closer examination showed dilated conjunctival vessels and minute yellow dots on the surface of the lesion. Adjacent to this, there was a black nodular lesion, 7 x 6 mm in size, with a thinning out of the overlying sclera [Figure 1] and positive transillumination. Retinal examination with the Goldmann contact lens was normal. B-scan ultrasonography confirmed the scleral ectasia. A clinical diagnosis of oculosporidiosis of the bulbar conjunctiva with associated scleral thinning and staphyloma was made. No evidence of residual nasal rhinosporidiosis was found on a repeat ENT evaluation.

Under peribulbar anaesthesia, the fleshy conjunctival lesion was excised and its base was cauterised, along with cryoapplication (double freeze) to the adjacent staphyloma. A repeat cryoapplication was required one month later as the staphyloma had not shown significant regression following the first intervention.

The excised specimen measured 1 cm x 0.5 cm. Histopathological sections were stained with hematoxylin and eosin. Examination under the light microscope showed sporangia of different sizes containing spores, surrounded by a vascular fibromyxomatous stroma infiltrated by inflammatory cells [Figure 2]. The inflammatory cells included lymphocytes, plasma cells, eosinophils, neutrophils and occasional giant cells which resembled foreign body giant cells. Sections stained with Periodic Acid Schiff (PAS) showed magenta-coloured sporangial walls and spores in a diffusely pink connective tissue background, a picture typical of rhinosporidiosis.

The patient was put on tablet dapsone 100 mg per day, 6 days a week, for 6 months. No adverse effects were noted due to dapsone therapy. At the end of one year, the staphyloma had regressed totally and there were no signs of recurrence of the rhinosporidial lesion.

Case 2

A 21-year-old male presented with a 3-month history of a dark lesion in the right eye. The lesion had been gradually increasing in size and was not associated with any other ocular or systemic symptoms. He came from Vaikkom in Kerala, where again, rhinosporidiosis is endemic. This patient also gave a history of regularly bathing in the local pond.

On examination, his vision was 6/6 in both eyes. The right eye showed a red fleshy lesion with small yellow dots on its surface. The lesion was located on the bulbar conjunctiva in the inferotemporal quadrant near the lower fornix. There was associated thinning and ectasia of the adjacent sclera over an area measuring 5 x 4 mm. Retinal examination was normal and B-scan ultrasonography confirmed the scleral ectasia. The left eye was normal. A clinical diagnosis of oculosporidiosis of the bulbar conjunctiva with adjacent scleral thinning and staphyloma was made. A detailed systemic and ENT evaluation did not reveal any other rhinosporidial lesions in the body.

Excision of the conjunctival lesion with cauterisation of its base was done, along with cryoapplication to the adjacent staphyloma similar to the first case. Histopathological examination showed a picture typical of rhinosporidiosis. Post-operatively, the patient was put on dapsone for 6 months. Over a period of one year, the staphyloma regressed completely with little residual scarring and without any recurrences of the rhinosporidial lesion. This patient also did not suffer from any adverse effects due to dapsone therapy.

 Discussion



Although the conjunctiva is described as the most common site of involvement in oculosporidiosis, involvement of the bulbar conjunctiva is relatively rare.[3] The classical conjunctival lesion in oculosporidiosis presents as a red, fleshy, pedunculated polypoid lesion in the palpebral conjunctiva with multiple yellow dots representing the sporangia on the surface. When the infection is in the bulbar conjunctiva, there is no space for the oculosporidium to grow out as a polyp as the affected area is pressed by the lids. Hence, the lesions in the bulbar conjunctiva are usually sessile and flatter in appearance, and in many cases, the diagnosis may be missed unless a high index of suspicion is maintained.

Staphyloma formation is a rare manifestation of oculosporidiosis.[4] This has been specifically noted in association with bulbar conjunctival lesions. In such lesions, as polypoid growth is prevented by the pressure of the lids, instead of growing out as a polyp, the oculosporidium spreads along the bulbar conjunctiva and deep towards the sclera. It has been postulated that some enzymatic substance produced by the organism corrodes the sclera resulting in thinning and staphyloma formation.[5] Probably it also causes alterations in the collagen causing weakening of the sclera, leading to scleral ectasia and staphyloma formation. The staphyloma gradually increases in size and may ultimately burst, resulting in the loss of the eyeball.

Rhinosporidial lesions are notorious for their propensity for recurrence, which may occur over a span of several years. Care should be taken to ensure that the lesion is completely excised. Cauterisation of the base of the lesion after excision and postoperative dapsone therapy are additional measures to reduce the chance of recurrence. Dapsone prevents the uptake of para amino benzoic acid by the micro-organism by competitively inhibiting the enzyme, folate synthetase. This interferes with the synthesis of folic acid, which is essential for the formation of DNA. Thus, it decreases the formation and maturation of spores. It also causes fibrosis and shrinkage of the lesion, causing its regression and reducing chances of recurrence. Both our patients tolerated dapsone well and did not suffer from any adverse effects.

Scleral and corneal grafts have been described in the treatment of staphyloma associated with oculosporidial lesions.[6],[7],[8] However, the staphyloma in both our patients showed complete regression after excision of the conjunctival oculosporidial lesion with cauterisation of the base, followed by cryoapplication to the staphyloma. Hence, cryotherapy may be a simpler and more cost effective alternative treatment for staphylomas associated with oculosporidiosis of the bulbar conjunctiva.

References

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2Reidy JJ, Sudesh S, Klafter AB, Olivia C. Infection of the conjunctiva by Rhinosporidium seeberi. Surv Ophthalmol 1997;41:409-13.
3 In : Rhinosporidiosis in man. Karunaratne WA, editor. London: Athlone Press, University of London; 1964. p 64.
4De Doncker RM, De Keizer RJ, Oosterhuis JA, Maes A. Scleral melting in a patient with conjunctival rhinosporidiosis. Br J Ophthalmol 1990;74:635-7.
5Kuriakose ET. Oculosporidiosis: Rhinosporidiosis of the eye. Br J Ophthalmol 1963;47:346-9.
6Kuriakose ET. Scleral transplantation in scleral staphylomas caused by Oculosporidiosis. Indian J Ophthalmol 1979;27:227-8.
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