<p>Improved Efficacy of Topical Latanoprost 0.005% Demonstrated by Corneal Biomechanical Correcting Modified Goldmann Prism</p>

Abstract

To evaluate intraocular pressure (IOP) reduction measured by a Goldmann applanation tonometer (GAT) prism and a modified surface Goldmann (CATS) prism with the institution of a topical prostaglandin analog (PGA) or alternatively a topical beta blocker. Design: Prospective, open-label, randomized, controlled, and reference device comparison. Methods: Thirty-six (36) treatment naïve glaucoma patients (72 eyes) were randomized equally to treatment with latanoprost 0.005% or timolol maleate 0.5%. Each patient underwent IOP measurement with standard GAT and CATS prisms before and at 1, 3, and 6 months of treatment. Central corneal thickness (CCT) and corneal hysteresis (CH) were also measured. Medication response was defined as a 20% reduction in IOP from baseline. Results: The CATS prism demonstrated the IOP reduction with topical latanoprost at a mean of 1.9 mmHg lower than the IOP measured with GAT (p=0.01). The CATS and GAT prisms detected no difference in IOP reduction with timolol (p=0.23). The number of latanoprost treatment nonresponders was reduced from 36.1% measured with GAT to 13.8% when measured with the CATS prism (p=0.005). Timolol indicated no difference in the treatment non-response rate at 22.2% (p=0.999). CH increased significantly with latanoprost treatment by an average of 0.55 mmHg (p=0.014) and remained unchanged with timolol at −0.014 mmHg (p=0.68). Discussion: IOP reduction and responder rates were increased when measured with a CATS prism in patients using latanoprost and not with timolol use. Latanoprost-induced alterations in corneal biomechanics may dampen the actual IOP reduction measured with a standard GAT prism. Clinical Trial Registration: ClinicalTrials.gov NCT04178863.

<p>Icare Home Tonometer: A Review of Characteristics and Clinical Utility</p>

“…Although some of these cases demonstrate changes in IOP demonstrated on Icare HOME before and after a surgical or medical intervention, it should also be noted that procedures such as a trabeculectomy as well as IOPlowering medications can affect corneal biomechanics and alter true changes in IOP measurement. 38,39 Case 1…”

Effect of prostaglandin analogues on central corneal thickness in patients with glaucoma: A systematic review and meta-analysis with trial sequential analysis

“…Ten randomized trials that evaluated the effect of prostaglandin on CCT and met our inclusion criteria were considered for analysis. Two RCTs[ 18 29 ] were excluded as relevant data could not be retrieved. Finally, we included eight trials reporting 879 patients in the analysis.…”

Corneal Crosslinking Biomechanics Evaluated by a Novel and Easily Implemented Differential Tonometry Method

“…[16][17][18][19] The differential tonometry between CATS and GAT IOP may likely demonstrate characteristic changes following pharmacological and surgical interventions which are known to alter corneal biomechanics with the advantage that the CATS and GAT prisms were designed to have zero overall bias using the same measurement device (alternating prisms) and the same measurement technique. 19,24 Potential future studies include examining differential CATS-GAT IOP measurement indicating biomechanical changes following LASIK and corneal transplant procedures. Also, the uncharacteristic finding of minimal differential CATS-GAT IOP in a thin cornea may be diagnostic of biomechanical behaviors seen in early keratoconus and ectatic corneal disease processes.…”

“…Several studies have described differential tonometry to measure changes in corneal stress. [16][17][18][19] Recent clinical studies using a corneal indentation device (CID) to perform continuous differential tonometry have demonstrated in vivo measurement of corneal tangent modulus, by applying variable corneal applanation and determining the slope of the force displacement curve. [20][21][22] A modified curved applanating surface Goldmann prism (CATS) has been developed to replace the standard flat surfaced Goldmann prism on any Goldmann type tonometer.…”