Treatment of Microsporidial Treatment of Microsporidial Keratitis with HexamidineKeratitis with Hexamidine

Alex KH LAUAlex KH LAU11

Colin SH TANColin SH TAN11

Wee Jin HENGWee Jin HENG11

11Dept of OphthalmologyDept of OphthalmologyTan Tock Seng Hospital, SingaporeTan Tock Seng Hospital, Singapore

The authors have no financial interest in the subject matter of this e-poster.

IntroductionIntroduction

Microsporidia are tiny, spore-forming, Microsporidia are tiny, spore-forming, obligate intracellular eukaryotic protozoa (Figure 1). obligate intracellular eukaryotic protozoa (Figure 1).

In humans, microsporidia are opportunistic In humans, microsporidia are opportunistic pathogens that usually cause diseases primarily in pathogens that usually cause diseases primarily in immunocompromised patients with Human immunocompromised patients with Human Immunodeficiency Virus (HIV) infection. Immunodeficiency Virus (HIV) infection.

2 clinical entities of ocular microsporidiosis have 2 clinical entities of ocular microsporidiosis have been describedbeen described11: : Corneal stromal keratitis in immunocompetent patients; Corneal stromal keratitis in immunocompetent patients;

caused by caused by Nosema Nosema and and MicrosporidiumMicrosporidium and and Superficial punctate keratoconjunctivitis in Superficial punctate keratoconjunctivitis in

immunocompromised individuals; mostly caused by immunocompromised individuals; mostly caused by EncephalitozoonEncephalitozoon. .

Figure 1

IntroductionIntroduction Treatment of ocular microsporidiosis is Treatment of ocular microsporidiosis is

difficult and, to date, no definitive treatment difficult and, to date, no definitive treatment exists.exists.

Previously described treatment options Previously described treatment options includeinclude2-92-9: : Debridement, Debridement, Topical antibiotics (fluoroquinolones, Topical antibiotics (fluoroquinolones,

propamidine isethionate, fumagillin),propamidine isethionate, fumagillin), Systemic anti-fungals & anti-helminths Systemic anti-fungals & anti-helminths

(itraconazole, albendazole) and(itraconazole, albendazole) and Topical steroids.Topical steroids.

ObjectivesObjectives

We present a series of four cases of We present a series of four cases of microsporidial keratoconjunctivitis in microsporidial keratoconjunctivitis in immunocompetent individuals who were immunocompetent individuals who were treated successfully with topical treated successfully with topical hexamidine di-isethionate. hexamidine di-isethionate.

Case 1Case 1 48 year old Caucasian male 48 year old Caucasian male History of mud entered both eyes during History of mud entered both eyes during

rugby game in Cambodia. rugby game in Cambodia. Visual acuity was 6/12 in the right eye and Visual acuity was 6/12 in the right eye and

intraocular pressure (IOP) was 34mmHg. Slit intraocular pressure (IOP) was 34mmHg. Slit lamp examination revealed follicular lamp examination revealed follicular conjunctivitis, multifocal subepithelial conjunctivitis, multifocal subepithelial infiltrates, 2+ anterior chamber cells, as well infiltrates, 2+ anterior chamber cells, as well as keratic precipitates on the endothelium as keratic precipitates on the endothelium (Figures 2 & 3).(Figures 2 & 3).

Diagnosis of right microsporidial keratouveitis Diagnosis of right microsporidial keratouveitis was confirmed with modified trichrome stain of was confirmed with modified trichrome stain of corneal epithelial scrapings.corneal epithelial scrapings.

Patient was HIV negative.Patient was HIV negative. He was treated with hexamidine di-He was treated with hexamidine di-

isethionate, dexamethasone (preservative isethionate, dexamethasone (preservative free), moxifloxacin and brimonidine.free), moxifloxacin and brimonidine.

Visual acuity recovered slowly to 6/6 over 3 Visual acuity recovered slowly to 6/6 over 3 months with minimal subepithelial scarring months with minimal subepithelial scarring (Figure 4).(Figure 4).

Figure 2

Figure 3

Figure 4

Case 2Case 2 17 year old Chinese female 17 year old Chinese female Developed redness and pain in the right Developed redness and pain in the right

eye 2 weeks after contact with mud.eye 2 weeks after contact with mud. Visual acuity was 6/6 bilaterally. There Visual acuity was 6/6 bilaterally. There

were multiple, coarse corneal epithelial & were multiple, coarse corneal epithelial & sub-epithelial infiltrates and follicular sub-epithelial infiltrates and follicular conjunctivitis (Figures 5 & 6). conjunctivitis (Figures 5 & 6).

Diagnosis of microsporidial keratitis was Diagnosis of microsporidial keratitis was confirmed with modified trichrome stain.confirmed with modified trichrome stain.

She was treated with hexamidine di-She was treated with hexamidine di-isethionate, levofloxacin and oral isethionate, levofloxacin and oral albendazole.albendazole.

The infection resolved over 3 weeks. The infection resolved over 3 weeks. Microsporidia keratitis subsequently Microsporidia keratitis subsequently developed in the left eye and was developed in the left eye and was successfully treated with hexamidine di-successfully treated with hexamidine di-isethionate. isethionate.

Figure 5

Figure 6

Case 3Case 3 23 year old Chinese male 23 year old Chinese male Reported redness and pain in the left eye 4 Reported redness and pain in the left eye 4

days after contact with mud. days after contact with mud. He was treated for viral conjunctivitis with He was treated for viral conjunctivitis with

topical tobramycin and dexamethasone. topical tobramycin and dexamethasone. Five days later, he developed sub-epithelial Five days later, he developed sub-epithelial infiltrates which worsened over the infiltrates which worsened over the following week (Figures 7 & 8). following week (Figures 7 & 8).

A clinical diagnosis of microsporidia A clinical diagnosis of microsporidia keratitis was made and he was treated with keratitis was made and he was treated with topical hexamidine and levofloxacin. topical hexamidine and levofloxacin.

Diagnosis was confirmed from corneal Diagnosis was confirmed from corneal scrapings with modified trichrome stain.scrapings with modified trichrome stain.

The infection resolved over the next 2 The infection resolved over the next 2 weeks with no corneal scarring (Figure 9). weeks with no corneal scarring (Figure 9).

HIV status was negative.HIV status was negative.

Figure 9

Figure 8

Figure 7

Case 4Case 4

63 year old Chinese male 63 year old Chinese male Presented with redness, blurring of vision, pain, Presented with redness, blurring of vision, pain,

photophobia and discharge in the right eye. photophobia and discharge in the right eye. VA was 6/7.5 and diffuse subepithelial infiltrates VA was 6/7.5 and diffuse subepithelial infiltrates

were seen with few keratic precipitates. were seen with few keratic precipitates. Clinical diagnosis of microsporidial keratitis was Clinical diagnosis of microsporidial keratitis was

mademade He was started on hexamidine di-isethionate and He was started on hexamidine di-isethionate and

the keratitis resolved completely after 6 weeks of the keratitis resolved completely after 6 weeks of treatment.treatment.

DiscussionDiscussion Our case series reports the successful treatment of ocular microsporidiosis Our case series reports the successful treatment of ocular microsporidiosis

with hexamidine and its manifestations in healthy, immunocompetent with hexamidine and its manifestations in healthy, immunocompetent individuals.individuals.

There are increasing reports describing ocular microsporidiosis in healthy There are increasing reports describing ocular microsporidiosis in healthy individuals. This could be explained by the increased awareness of this individuals. This could be explained by the increased awareness of this rare infection and improvement in the diagnostic techniquesrare infection and improvement in the diagnostic techniques10, 1110, 11. .

Our first case presented with a moderately severe uveitic response in the Our first case presented with a moderately severe uveitic response in the anterior chamber, which has not previously been reported. This could be anterior chamber, which has not previously been reported. This could be due to sterile inflammatory reaction, or may represent a new clinical due to sterile inflammatory reaction, or may represent a new clinical manifestation of ocular microsporidiosis.manifestation of ocular microsporidiosis.

Three of the 4 cases in our series developed microsporidial keratitis after Three of the 4 cases in our series developed microsporidial keratitis after exposure to mud, which is consistent with previous reports of trauma as exposure to mud, which is consistent with previous reports of trauma as one of the predisposing factors for ocular microsporidiosis in healthy one of the predisposing factors for ocular microsporidiosis in healthy individuals. The others include topical steroid therapy (Case 3) and contact individuals. The others include topical steroid therapy (Case 3) and contact lens wear.lens wear.

Conclusion Conclusion Microsporidia are increasingly become Microsporidia are increasingly become

recognised as pathogens in healthy individuals. recognised as pathogens in healthy individuals. High index of suspicion is required to make the High index of suspicion is required to make the

correct diagnosis, especially in cases presented correct diagnosis, especially in cases presented with atypical multifocal diffuse epithelial keratitis. with atypical multifocal diffuse epithelial keratitis.

History of ocular trauma, contact lens wear or History of ocular trauma, contact lens wear or usage of topical steroid therapy are predisposing usage of topical steroid therapy are predisposing factors which should raise the index of suspicion. factors which should raise the index of suspicion.

Topical hexamidine di-isethionate is an effective Topical hexamidine di-isethionate is an effective alternative therapy to microsporidial alternative therapy to microsporidial keratoconjunctivitis. keratoconjunctivitis.

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