A comparison of applanation tonometry using conventional reusable goldmann prisms and disposable prisms.

To determine the agreement between intraocular pressure (IOP) measurements using conventional Goldmann applanation tonometry (GAT) and Tonosafe disposable prisms, and also to provide a comprehensive cost analysis of the use of both types of prisms
: In this prospective observational study, 198 eyes of 100 glaucoma patients had their IOPs measured by 5 consultant ophthalmologists. Data were analyzed using the Bland-Altman method of differences, and correlation was measured using the Pearson coefficient. An analysis of the cost incurred using the 2 methods over a 6-month period was performed.
The majority were Chinese (82%), with a male preponderance (57%). The range of IOPs as measured by GAT was 4 to 34 mm Hg. Using the Bland-Altman method to compare GAT and disposable prisms, the bias was 0.2 mm Hg. Tonosafe overestimated the IOP by 0.2 mm Hg in the right eye and underestimated it by 0.2 mm Hg in the left eye. The Tonosafe IOP correlated well with GAT, with a Pearson coefficient of correlation(r) of 0.91 (P<0.0005) for the right eye and 0.92 (P<0.0005) for the left eye, respectively. For those with GAT IOP≥21 mm Hg (n=26), Tonosafe underestimated the IOP by 0.35 mm Hg. The cost incurred by Tonosafe prisms was approximately 8 times that of GAT, but the cost differential reverses when GAT had to be replaced after every 100 cycles of disinfection.
We found a good correlation between Tonosafe prisms and conventional GAT in measuring the IOP. Tonosafe prisms may be of use, especially if the risk of transmission of infection is high. However, cost may limit its more widespread use.
AuthorsAndrew S H Tsai, Alicia C How, Daniel H W Su, Kelvin Y Lee, Tina T Wong, Shamira A Perera
JournalJournal of glaucoma (J Glaucoma) Vol. 23 Issue 8 Pg. 521-5 ( 2014) ISSN: 1536-481X [Electronic] United States
PMID23632407 (Publication Type: Journal Article, Observational Study)
  • Adult
  • Aged
  • Aged, 80 and over
  • Disposable Equipment
  • Female
  • Glaucoma (diagnosis, physiopathology)
  • Humans
  • Intraocular Pressure (physiology)
  • Male
  • Middle Aged
  • Prospective Studies
  • Retrospective Studies
  • Tonometry, Ocular (instrumentation, methods)
  • Young Adult

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!

Choose Username:
Verify Password:
Enter Code Shown: