The pressure phosphene tonometer—a clinical evaluation

Abstract

Aims Pressure phosphene tonometry is said to assess intraocular pressure by inducing a pressure phosphene. This study compared the results of this relatively new technique with Goldmann applanation tonometry. Methods A total of 100 patients (196 readings) in a general ophthalmology clinic at Dunedin Hospital who consented to take part in this study were randomised to receive by different examiners either pressure phosphene tonometry by a Proview TM eye pressure monitor (Bausch & Lomb Inc., Tampa, FL, USA) or Goldmann tonometry first. There was no communication between the examiners regarding results. Results Of the 196 attempted readings, pressure phosphene tonometer readings were only able to be obtained for 136 eyes (69%) compared to all 196 (100%) eyes with the Goldmann tonometer. The mean IOPs were 18.5 mmHg using the pressure phosphene tonometer and 16.0 mmHg using the Goldmann tonometer. The mean difference was þ 2.43 mmHg (95% confidence interval: 10.37 mmHg below to 15.22 mmHg above Goldmann readings). Conclusion This study found that 31% of patients could not perceive a pressure phosphene using the Proview TM eye pressure monitor. Data obtained from those who could perceive the phosphene indicated that large discrepancies between pressure phosphene tonometry and Goldmann tonometry were common.

Intraocular pressure assessment after laser in situ keratomileusis: a review

“…However, PPT had been found to be inconsistent as compared to GAT in normal eyes, 38 as well as in patients with glaucoma 39 . In addition, possibly up to 31% of patients may have difficulties in perceiving the pressure phosphene 40 . PPT has also been found to be accurate and reproducible in a narrow IOP range of 9–25 mmHg 41 .…”

“…39 In addition, possibly up to 31% of patients may have difficulties in perceiving the pressure phosphene. 40 PPT has also been found to be accurate and reproducible in a narrow IOP range of 9-25 mmHg. 41 It has been argued that the target IOP in current glaucoma management is well below 21 mmHg and within the PPT IOP range.…”

A Clinical Evaluation of Proview Pressure Phosphene Tonometry in Children

“…6,8,9,10,11 The only previous study of PPPT in children was a comparison to non-contact tonometry by Lievens et al 12 That study reported only 2.2% (two subjects out of 93, age range 4-12 years, mean age 8.5 years) were unable to report a phosphene. A few studies of adults with glaucoma have found much higher rates of patients unable to appreciate pressure phosphenes, 13,14 which may in part be due to extensive glaucomatous ganglion loss precluding appreciation of the phosphenes.…”

Intraocular pressure

“…4-12) -and found good correlation with GAT. [145][146][147][148] The Proview could still be useful for diurnal IOP estimations by patients themselves if several validating measurements are made side-by-side with the Goldmann or other accurate transcorneal tonometer. 143,144 Unfortunately, subsequent studies failed to confirm the accuracy of this device.…”