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 COMPARISON OF TEAR COLLECTION TECHNIQUE FOR DETECTION OF HSV TECHNIQUE FOR DETECTION OF HSV
DNA BY PCRDNA 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
SamplesCollected
per SubjectActive
stromal keratitis
Endotheliitis
Yamamoto S et al (1994) [Conventional PCR]
2/6(33.33%)
-Schirmer
Strips1
Kudo E et al (1996) [Nested PCR]
5/15(33.33%)
-Schirmer
Strips3.3
Pramod NP et al (2000) [(Conventional PCR]
12/40(30%)
-Schirmer
Strips2
Fukuda M et al (2003) [Real-time PCR]
8/14(57%)
0/3 Eye Rinse 1
Fukuda M et al (2008) [Real-time PCR]
13/22(59.1%)
0/3 Eye Rinse 1
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 categoriesPUK = Peripheral ulcerative keratitisA = Active Q = QuiescentP = with perforationV = Viral
RESULTS
Fig 2: PCR result in different clinical categories with capillary & Schirmer’s method PUK = Peripheral ulcerative keratitisA = Active Q = QuiescentP = with perforationV = 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
