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Detection of Ocular Disease by a Vision Center Technician & The Role of Frequency Doubling Technology Perimetry in this Setting
  1. Ravi Thomas1,
  2. Shoba Naveen2,
  3. Praveen Nirmalan3,
  4. Rajul Parikh3
  1. 1 Queensland Eye Institute, Australia;
  2. 2 Siloam Eye Hospital, L.V. Prasad Eye Institute, India;
  3. 3 L.V. Prasad Eye Institute, India
  1. * Corresponding author; email: rt{at}


Aim: To document the detection of significant ocular pathology by a vision centre technician in an emerging economy World Health Organization recommended eye care delivery setting, and determine whether a frequency-doubling perimeter (FDT) improves that performance.

Material and methods: Consecutive patients above the age of 12 years attending a vision center were included. A vision technician (VT) determined visual acuity and performed slit lamp examination, applanation tonometry and undilated fundus examination followed by a 20-1 FDT screening test. VT and FDT findings were compared to the gold standard of masked comprehensive examination by an ophthalmologist. Sensitivity, specificity and predictive values were calculated.

Results: 1764 of 1829 patients fulfilling the inclusion and exclusion criteria were analysed. The VT had sensitivity and specificity of 68 % and 90 % for detection of significant ocular disease; corresponding values for FDT alone were 87.8 % and 79 %. Seventy-one of the 115 patients having significant ocular pathology missed by the vision technician were detected by FDT. A positive finding by the vision technician and/or positive FDT had a positive predictive value of 47%.

Conclusions: An examination by a vision center technician within the accepted WHO model may usefully leverage limited ophthalmological capacity in emerging economies. Adjunctive FDT testing may further improve VT referral efficiency.

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