 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, AIIMS COMPARISON 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) Authors (year) [PCR type] Subjects, proportion (%)* Sample Method Samples Collected per Subject Active stromal keratitis Endotheliitis Yamamoto S et al (1994) [Conventional PCR] 2/6 (33.33%) - Schirmer Strips 1 Kudo E et al (1996) [Nested PCR] 5/15 (33.33%) - Schirmer Strips 3.3 Pramod NP et al (2000) [(Conventional PCR] 12/40 (30%) - Schirmer Strips 2 Fukuda M et al (2003) [Real-time PCR] 8/14 (57%) 0/3Eye Rinse1 Fukuda M et al (2008) [Real-time PCR] 13/22 (59.1%) 0/3Eye Rinse1 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

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

Patients Inclusion Criteria –Clinically diagnosed cases of active stromal keratitis and endotheliitis Exclusion criteria –Pure epithelial keratitis with no stromal involvement –History of oral acyclovir use within 1 month

Study Design Study group: 66 eyes( 59 patients) –52 unilateral & 7 bilateral Control group: 130 eyes of 90 patients –Contralateral eye of 50* unilateral affected patients –Both 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 Schirmer’s 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 categories PUK= Peripheral ulcerative keratitis A= Active Q= Quiescent P= with perforation V= Viral RESULTS

Fig 2: PCR result in different clinical categories with capillary & Schirmer’s method PUK= Peripheral ulcerative keratitis A= Active Q= Quiescent P= with perforation V= Viral

Figure 3: PCR result using Capillary and Schirmer's tear sampling method  PCR 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 Schirmer’s strip and fire- polished micro capillary tube are equally effective for HSV DNA detection

Address for Correspondence :  Dr Radhika Tandon  Professor of Ophthalmology   Dr. RP Centre for Ophthalmic Sciences,  All India Institute of Medical Sciences  (AIIMS)  New Delhi, India