Abstract
Purpose :
Evaluate the sensitivity and specificity of IOP in detecting a need for treatment or progression of glaucomatous optic neuropathy by loss of retinal nerve fiber layer (RNFL) in ocular hypertension (OHT) and open-angle glaucoma (OAG) using Goldmann applanation tonometry (IOPg) and modified applanation surface Goldmann tonometry (IOPc)
Methods :
A retrospective cross-sectional study was performed in a multi-specialty ophthalmology practice on 1741 eyes in 952 patients: 164 N, 502 GS, 490 OHT,491 POAG, and 89 normal tension glaucoma (NTG) eyes. Primary outcome measures included glaucomatous optic neuropathy (GON) demonstrated by RNFL loss measured by serial OCT over a period of 2.8 years (average of 3.9 visits) to produce receiver operating characteristic (ROC) curves of sensitivity and specificity with paired IOPc and IOPg measurements. Secondary outcome measures were corneal hysteresis (CH), and central corneal thickness (CCT).
Results :
Maximum sensitivity and specificity in diagnosing new onset POAG or NTG using IOPc (77%/91%@23mmHg) and using IOPg (70%/86%@22mmHg)(p<0.001). OHT, being defined by IOP, was included in a separate analysis of those patients with POAG/NTG/OHT requiring treatment (OHT≥26mmHg): IOPc (91%/96%@24mmHg) and IOPg (82%/88%@23mmHg)(p<0.001). An increase of IOPc ≥ 2mmHg over IOPg indicated a 79% probability of progressive GON by RNFL loss in treated POAG/NTG (p<0.001). Likewise, a CH of < 9.0mmHg also indicated 79% probability of progressive GON (p<0.001).
Conclusions :
IOP is a primary indicator in the diagnosis of OAG but not significantly reliable alone to make a decision to treat or alter treatment. A modified Goldmann prism demonstrated significantly higher sensitivity and specificity diagnosing POAG and NTG as well as directing treatment. IOP remains a valuable leading indicator of GON with significantly high sensitivity and specificity depending upon where in the spectrum of open-angle glaucoma it is measured. The IOP information may be improved by newer methods of measurement.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.