240 AMERICAN JOURNAL OF OPHTHALMOLOGY February, 1990

Fig. 1 (English and associates). Scanning electronmicroscopic view of eyelid margin displaying theprotruding tail of a demodectic mite beside an eye­lash (X 550).

scanning electron microscopy.' We were inter­ested to see if these parasites could also beisolated on the eyelid margin.

After a full-thickness resection for a shorten­ing procedure of the lower eyelid of a 35-year­old woman, we took the specimen and placed itin 4% glutaraldehyde solution. This was thenplaced in 100% amylacetate and critically pointdried. The sample was oriented on an alumi­num stub, gold coated in a polaron sputtercoater with 20 nm of gold, and viewed with ascanning electron microscope. After orientationof the eyelid under low power with the electronmicroscope, the tissue fragment was rotated toallow the eyelid margin to be examined inprofile. Eyelashes were examined under highermagnifications, and acarid infestation of thecilium was recorded (Fig. 1).

The tail of the parasite Demodex folliculorumwas observed as a dome-shaped object contigu­ous with an eyelash and protruding from theeyelid margin. It displayed the characteristicannular bands found on the abdomen. Thepeculiar pattern of these striations was ob­served under higher magnification (Fig. 2).Only the terminal portion of the abdomen ofthe parasite was identified.

Demodex brevis, the other species of the mitefound in the eyelid, occurring in the meibomianglands and pilosebaceous complex, has a point­ed caudate extremity and was not observed inour patient. The degree of infestation was not as

Fig. 2 (English and associates). Higher magnifica­tion of parasite showing classic inscriptions on theabdomen (x 2,320).

heavy as that recorded in the facial skin studiesin which multiple parasites were noted aroundhairs.

Reference

1. Crosti, c., Menni, 5., Sala, F., and Piccinno, R.:Demodectic infestation of the pilosebaceous follicle.J. Cutan. Pathol. 10:257, 1983.

Capnocytophaga canimorsus as theCause of a Chronic CornealInfection

Marc D. de Smet, M.D.,Chi Chao Chan, M.D.,Robert B. Nussenblatt, M.D.,and Alan G. Palestine, M.D.Laboratory of Immunology, National Eye Institute.

Inquiries to Marc D. de Smet, M.D., Laboratory ofImmunology, National Eye Institute, Bldg. 10, Rm.10N202, Bethesda, MD 20892.

Dysgonic fermenter 2, a normal inhabitant ofthe dog's mouth, closely resembles the Capno­cytophaga species found in humans. The latterhave been shown to cause a chronic keratitisresembling a fungal or Acanthamoeba infec-

Vol. 109, No.2 Letters to the Journal 241

tion. I ,2 Dysgonic fermenter 2 is recognized as acause of fulminant septicemia in patients with­out spleens or with alcoholic cirrhosis." Infec­tion frequently occurs after a dog bite or closecontact with dogs or cats. The organism, agliding gram-negative rod, is characterized byfastidious growth requirements. We treated apatient who developed a chronic deep cornealinfection that required prolonged antibiotictherapy over several months because of thisorganism.

A 46-year-old veterinarian was struck on theright eye by a carious tooth while extracting itfrom a poodle with severe gingivitis. The pa­tient sustained a superficial corneal lacerationextending into the anterior stroma without anyretained foreign body. He was treated withtopical sulfacetamide.

While taking this regimen, the patient devel­oped an intense photophobia and conjunctivalinjection. The site of injury was debrided andshowed a staphylococcal species which wastreated with topical fortified cefazolin (50 mg/ml) for two weeks. Visual acuity improved toR.E.: 20/25 with partial resolution of the pho­tophobia. Visual acuity again deteriorated andthe photophobia worsened within a month. Amicroscopic abscess growing C. perfringens wasnoted and debrided. The cornea was treatedwith topical fortified vancomycin hydrochlor­ide. Visual acuity improved to R.E.: 20/25, onlyto worsen within one month to R.E.: 20/200despite treatment.

Two months later and three days before ad­mission to the National Eye Institute, visual

Fig. 1 (de Smet and associates). Slit-lamp appear­ance of the corneal subendothelial infiltrate one daypostoperatively. Note the satellite lesions and thesharp demarcation of each lesion.

acuity had decreased to counting fingers. Thepatient had an anterior chamber hypopyon. Anaspirate of the anterior chamber did not showany organisms, but it did contain numerouspolymorphonuclear cells. Slit-lamp examina­tion disclosed marked conjunctival injectionand an edematous cornea with an intact epithe­lium. Plaquelike deposits were seen at the levelof the endothelium (Fig. 1). These deposits hadwell defined borders extending inward from theperipheral cornea. Smaller satellite lesionswere also noted. A biopsy specimen taken fromone of the lesions did not show any organismsbut, once again, was characterized by a profu­sion of polymorphonuclear leukocytes. Afterfive days, the anaerobic cultures disclosed athin, nonspore-forming gram-negative rodmeasuring 1 to 311m. This was characterized asa dysgonic fermenter 2 organism (Fig. 2).

The patient was treated with a combinationof intravenous cefazolin, 1 g every six hours,and topical eye drops of cefazolin sodium, 50mg Zml every hour. The patient was laterswitched to penicillin, 2,000,000 units intrave­nously every six hours and 100,000 U/ml topi­cally, after he developed an allergic reaction tocefazolin. The eyedrops were continued forseveral months. Visual acuity improved to R.E.:20/30 with a gradual lessening of the photo­phobia. The eye drops were finally discontinuedafter the endothelial deposits and the photo­phobia had resolved.

Dysgonic fermenter 2 behaves in a way simi­lar to other Capnocytophaga species. It is charac­terized by severe pain, decreased visual acuity,

Fig. 2 (de Smet and associates). Appearance of theorganism on Gram stain after seven days in culture(x 100). The organism is a gram-negative rod mea­suring 1 to 3 urn.

242 AMERICAN JOURNAL OF OPHTHALMOLOGY February, 1990

and slow, fastidious growth in culture. Anaero­bic cultures must be maintained beyond theusual five days to detect this organism. Thisgrowth also occurs in vivo, which explains whythe patient suffered three recurrences, eachtime with a deeper involvement. The bacteri­um, because of its slow growth, requires pro­longed therapy for its eradication. Photopho­bia, possibly related to bacterial spread alongcorneal nerves, is probably the best indicator ofpersistent infection. Dysgonic fermenter 2 has awide spectrum of antibiotic sensitivity. It isparticularly sensitive to penicillin, clindamy­cin, and rifampin.! Dysgonic fermenter 2 corne­al involvement can mimic fungal, acan­thamebal, or stromal keratitis. One shouldsuspect this organism in cases where a dog'soral flora may have infected the cornea.

References

1. Parnel. G. J., Buckley, D. J., Frucht, J., Krausz,H., and Feldman, S. T.: Capnocytophaga keratitis.Am. J. Ophthalmol. 107:193, 1989.

2. Heidemann, D. G., Pflugfelder, S. c.. Kronish,J., Alfonso, E. c.. Dunn, S. P., and Ullman, S.: Nec­rotizing keratitis caused by Capnocytophaga ochracea.Am. J. Ophthalmol. 105:655, 1988.

3. Brenner, D. J., Hollis, D. G., Fanning, G. R., andWeaver, R. E.: Capnocqtophaga canimorsus sp. nov.(formerly CDC group DF-2), a cause of septicemiafollowing dog bite, and C. cynodegmi sp. nov., a causeof localized wound infection following dog bite. J.Clin. Microbiol. 27:231, 1989.

4. Verghese, A., Hamati, F., Berk, S., Franzus, B.,Berk, 5., and Smith, J. K.: Susceptibility of dysgonicfermenter 2 to antimicrobial agents in vitro. Antirni­crob. Agents Chemother. 32:78, 1988.

Microsporidia Infection of theCornea in a Man Seropositive forHuman Immunodeficiency Virus

Careen Y. Lowder, M.D.,David M. Meisler, M.D.,James T. McMahon, Ph.D.,David L. Longworth, M.D.,and Isobel Rutherford, M.D.Departments of Ophthalmology (C.Y.L., D.M.M.),Pathology (J.T.M.), Infectious Disease (D.L.L.), andMicrobiology (l.R.), Cleveland Clinic Foundation.

Inquiries to Careen Y. Lowder, M.D., Department ofOphthalmology, Cleveland Clinic Foundation, 9500 Eu­clid Ave., Cleveland, OH 44195-5024.

Microsporidia are obligate intracellular para­sites that infect mammals, arthropods, fish, andbirds. They rarely cause disease in humans.'Recently, however, microsporidia have beenassociated with hepatitis and enteritis in pa­tients with the acquired immunodeficiency syn­drome (AIDS).2 We encountered a case of mi­crosporidia corneal infection in an individualwho was seropositive for human immunodefi­ciency virus antibodies.

A 30-year-old homosexual man with AIDS­related complex and known to be HIV­seropositive for three years, began having re­current episodes of redness and crusting ofboth eyes in November 1988. Conjunctival cul­tures grew Streptococcus viridans and coagu­lase-negative staphylococcus. The patient wastreated with the appropriate topical antibioticswithout resolution of the condition. Ocularexamination in February 1989 disclosed a best­corrected visual acuity of 20/25 in each eye.Slit-lamp examination showed marked bilateralconjunctival hyperemia, mixed follicular-papil­lary tarsal conjunctival reaction, and diffusepunctate epithelial keratopathy. Conjunctivalcultures for bacteria, fungi, chlamydia, herpessimplex virus, herpes zoster virus, and adeno­virus were negative. The patient's epithelialkeratopathy worsened over the next threemonths, and visual acuity deteriorated to 20/60in each eye (Fig. 1). In May 1989 corneal epithe­lium was scraped from the right eye and healedrapidly, but the epithelial keratopathy recurred.

Epithelial scrapings were submitted for cul-

Fig. 1 (Lowder and associates). Slit-lamp photo­graph of punctate epithelial keratopathy.