radhika tandon, md, dnb, frcs, frcophth, manoj sharma, md & gita satpathy, md * ...
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Radhika Tandon, MD, DNB, FRCS, FRCOphth, Manoj Sharma, MD & Gita Satpathy, MD *Department of Cornea, Cataract & Refractive Surgery and *Ocular Microbiology Dr Rajendra Prasad Centre For Ophthalmic Sciences, AIIMSCOMPARISON OF TEAR COLLECTION TECHNIQUE FOR DETECTION OF HSV DNA BY PCR The authors have no financial interest in the subject matter of this poster.
*Total no. of subjects with shedding of HSV-1 DNA/total no. of subjects assessed (percentage of patients with shedding of HSV-1 DNA) Review of Literature- Shedding of Herpes simplex virus type 1 (HSV-1) DNA in active stromal keratitis and / or endotheliitis, as detected by polymerase chain reaction (PCR) analysis of tear samples obtained by different methods
Authors (year) [PCR type]Subjects, proportion (%)*Sample MethodSamplesCollectedper Subject
Active stromal keratitisEndotheliitisYamamoto S et al (1994) [Conventional PCR]2/6(33.33%)-SchirmerStrips1Kudo E et al (1996) [Nested PCR]5/15(33.33%)-SchirmerStrips3.3Pramod NP et al (2000) [(Conventional PCR]12/40(30%)-SchirmerStrips2Fukuda M et al (2003) [Real-time PCR]8/14(57%)0/3Eye Rinse 1Fukuda M et al (2008) [Real-time PCR]13/22(59.1%)0/3Eye Rinse 1
To compare PCR results in tear samples obtained by two different methods Schirmer's strip & fire-polished micro capillary tube in patients with clinically diagnosed viral stromal keratitis and endotheliitis AIM
PatientsInclusion Criteria Clinically diagnosed cases of active stromal keratitis and endotheliitis
Exclusion criteria Pure epithelial keratitis with no stromal involvementHistory of oral acyclovir use within 1 month
Study DesignStudy group: 66 eyes( 59 patients)52 unilateral & 7 bilateral Control group: 130 eyes of 90 patientsContralateral eye of 50* unilateral affected patientsBoth eyes of 40 normal volunteers
*Of 52 unilaterally affected, 2 patients had contralateral phthisis bulbi, sample was not taken from the phthisical eye
Tear Collection Methods Tear samples of each patient were collected using Schirmers filter paper strip and fire polished micro- capillary tubes in a randomized sequence from the anaesthetized inferior fornix and were subjected to PCR for detection of HSV DNA
Fig. 1 Distribution of tear samples from various clinical categoriesPUK= Peripheral ulcerative keratitisA= Active Q= QuiescentP= with perforationV= ViralRESULTS
Fig 2: PCR result in different clinical categories with capillary & Schirmers method PUK= Peripheral ulcerative keratitisA= Active Q= QuiescentP= with perforationV= Viral
Figure 3: PCR result using Capillary and Schirmer's tear sampling methodPCR positivity in tear samples collected by either method were not significantly different (p=0.23).
Conclusion 20% cases of active Herpetic stromal keratits and endotheliitis had positive tear PCR test result Tear samples collected by Schirmers strip and fire- polished micro capillary tube are equally effective for HSV DNA detection
Address for Correspondence :Dr Radhika TandonProfessor of Ophthalmologyradhika_tan@yahoo.com
Dr. RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences (AIIMS) New Delhi, India