Home Tonometry Research Articles

Clinical utility, feasibility of home tonometry using iCare HOME by glaucoma patients.

To determine agreement between diurnal variation testing (DVT) of intraocular pressure (IOP) with Goldmann applanation tonometer (GAT) and iCare HOME (IH) by an optometrist (OP) and home monitoring by participants (PT). Patients (18-80 years) with glaucoma and suspects were enrolled. IH IOP and GAT were taken by an OP at 2 h intervals from 8 AM to 4 PM on Day 1 and PT between 6 AM and 9 PM, for the next 2 days. IOP, date, and time were viewed via iCare LINK software. 72.9. 51/70) PT trained were able to take reliable readings. One hundred two eyes (51 patients, age 53 ± 16 yrs) were analyzed. Correlation between optometrist (OP) and participants (PT) was strong and positive {IH OP-IH PT- r = 0.90, p-0.0001;IH PT-GAT- r = 0.79, p-0.0001}. Agreement by Bland Altman plots was limited {IH OP-IH PT mean 0.1 mmHg (95% LOA -5.3 to 5.5), IH PT-GAT 2.2 mmHg (-5.7 to 10.1)}. Intraclass correlation coefficient for IH OP-IH PT was 1.18 (95% CI 1.37-1.09). Intradevice {0.95 (95% CI 0.94-0.97)} and interrater repeatability {0.91 (0.79-0.96)} were good. 37% of eyes had a synchronous peak on GAT and IH during the day DVT. Home tonometry by iCare HOME is easy, feasible, but due to limited agreement cannot substitute GAT DVT.

Prediction model of contact forces and IOP during digital palpation of porcine eyes

Frequent intraocular pressure (IOP) measurements are desirable in the diagnosis and management of glaucoma. Most current tonometers utilize some form of corneal deformation to estimate the IOP, since trans-scleral tonometry suffers from loss of sensitivity. Tran-scleral and trans-palpebral tonometry, however, offer a pathway towards a non-invasive home tonometry. This article presents a mathematical model capturing the relationship between the IOP and the displacements imposed onto the sclera by externally applied forces. Similar to manual digital palpation tonometry, trans-scleral mechanical palpation makes use of two force probes that are advanced in a specific order and distance. Data from the applied forces and displacements, along with concurrent measurements of IOP is used to produce a phenomenological mathematical model. The experiments were carried out on enucleated porcine eyes.Two models are presented. Model 1 predicts IOP vs forces and displacements, while Model 2 predicts the baseline IOP (prior to applying the forces) as a function of the measured forces and displacements. The proposed models result in IOP errors of 1.65 mmHG and 0.82 mmHg, respectively. Model parameters were extracted using least-squares-based system identification methods. The results show that the proposed models can be used to estimate the baseline IOP with accuracy of ±1 mmHg over a pressure range of 10–35 mmHg, solely from measurement of tactile forces and displacements.

Home tonometry in the management of children with uveitis at risk for developing glaucoma

Children with uveitis are at increased risk for developing glaucoma secondary to the effects of inflammation and corticosteroid use. They require frequent follow-up to monitor intraocular pressure (IOP). The COVID-19 pandemic forced remote monitoring and telemedicine to reduce in-clinic patient volumes and disease transmission. This study investigates the impact of home tonometry on frequency of patient visits and management decisions.

Teaching home tonometry using a remote video link

Background/ObjectivesIntraocular pressure (IOP) is the primary modifiable risk factor in the progression of glaucoma. The ICare HOME is a self-tonometer which empowers patients to measure their own IOP and allows a more complete picture of diurnal IOP. This project aims to determine the feasibility of teaching patients to perform self-tonometry remotely using a remote video link.Subjects/MethodsThis prospective study involved 12 patients with glaucoma attending an outpatient ophthalmology clinic. Participants were provided with a rebound tonometer (Icare HOME) and instructions to attend remote teaching from home. An optometrist conducted a 30 min live video training session via NearMe with each patient. Following training, participants were asked to measure their own IOP, observed remotely by the optometrist. Successful participants were asked to take a series of home IOP measurements over 48 h. Questionnaires were used to evaluate perceptions on home tonometry and remote training.ResultsParticipants had an average age of 60.1 ± 15.5 years. 58% (7 of 12) were female. 83% (10 of 12) obtained successful diurnal measurements at home. All participants were happy with remote teaching, and none would have preferred training to be conducted face-to-face. All participants were interested in continuing home IOP monitoring.ConclusionsMost patients were able to perform home tonometry successfully when taught remotely, with a success rate similar to previously reported rates for face-to-face teaching using the same device. Most participants were receptive to using video calling as a platform for teaching home tonometry.

The Utility of iCare HOME Tonometry for Detection of Therapy-Related Intraocular Pressure Changes in Glaucoma and Ocular Hypertension

To assess whether iCare HOME rebound tonometry can detect therapy-related changes during self-monitoring of intraocular pressure (IOP). Prospective clinical trial. A total of 43 eyes (n= 27 subjects) with open-angle glaucoma or ocular hypertension were enrolled during standard-of-care clinic visits. Participants were grouped into control eyes managed on stable therapy (n= 18 eyes) or therapy change eyes undergoing selective laser trabeculoplasty (SLT, n= 8 eyes), initiating topical therapy (n= 8 eyes), or adding a second medication to existing monotherapy (n= 9 eyes). Subjects recorded IOP 4 times daily for 1 week using iCare HOME tonometry. Upon tonometer return, subjects underwent SLT or new medication start; an additional week of iCare HOME measurements was collected after 4 to 6 weeks. Control subjects recorded an additional week of measurements after 6 weeks. Measurements were grouped into 4 time periods (5-10 am, 10 am to 3 pm, 3-8 pm, 8 pm to 1 am). Goldmann applanation tonometry (GAT) was performed at each study visit for comparison. Detection of therapy response defined as an IOP reduction of ≥20%. For eyes that demonstrated a therapy response by GAT (n= 11), iCare HOME detected a therapy response in 90.9% of eyes in ≥1 time period and 45.5% of eyes in all 4 time periods. In eyes without a GAT-measured therapy response (n= 14), iCare HOME detected a response for 71.4% (n= 10) of eyes in ≥1 time period and for 7.1% of eyes (n= 1) at all 4 time periods. In treatment eyes, intraday and interday average minimum and maximum IOP, as well as interday IOP range, were significantly reduced after therapy without a significant change in intraday IOP range. Control group eyes did not demonstrate a significant change in average IOP minimum, maximum, or range between study weeks. Home tonometry with iCare HOME reliably detects therapy-related IOP changes in patients with glaucoma and ocular hypertension. Treatment responses correlated well with in-office GAT and may detect treatment responses missed by GAT. Intraocular pressure measurements via home tonometry provide additional clinical information regarding intraday and interday IOP fluctuation beyond standard of care in office GAT measurements. The iCare HOME is a valuable tool to monitor therapeutic efficacy in patients with glaucoma.

A Comparison of Short-Term Intraocular Pressure Fluctuation with Office-Based and Home Tonometry

A Comparison of Short-Term Intraocular Pressure Fluctuation with Office-Based and Home Tonometry

Home Self-tonometry Trials Compared with Clinic Tonometry in Patients with Glaucoma

This study examined characteristics of intraocular pressure (IOP) as measured during home tonometry in comparison with in-clinic tonometry in patients with glaucoma. Retrospective cross-sectional study of glaucoma patients who completed 1 week of self-tonometry at a single academic center. Patients with glaucoma who completed home tonometry trials with the iCare HOME tonometer (iCare USA) for any reason. Home IOP measurements were compared with in-clinic tonometry performed during the 5 visits preceding home tonometry. Maximum daily IOP was correlated to time of day. Generalized estimating equations were used to evaluate patient characteristics and clinic-derived variables that predicted differences between home and clinic IOP. IOP mean, maximum, minimum, range, standard deviation and coefficient of variation were compared between clinic and home tonometry. IOP mean daily maximum (MDM) and mean daily range were calculated to describe recurrent IOP spiking. A total of 107 eyes from 61 patients were analyzed. Mean age was 63.2 years (standard deviation [SD], 14.0 years) and 59.0% were women. Mean clinic and home IOPs were 14.5 mmHg (SD, 4.7 mmHg) and 13.6 mmHg (SD, 5.1 mmHg). Home tonometry identified significantly higher maximum IOP, lower minimum IOP, and greater IOP range than clinic tonometry (P < 0.001). Maximum daily IOP occurred outside of clinic hours (8 am-5 pm) on 50% of days assessed and occurred between 4:30 am and 8 am on 24% of days. Mean daily maximum IOP exceeded maximum clinic IOP in 44% of patients and exceeded target IOP by 3 mmHg, 5 mmHg, or 10 mmHg in 31%, 15%, and 6% of patients, respectively. Patient characteristics that predicted significant deviations between MDM and mean clinic IOP or target IOP in multivariate models included younger age, male gender, and absence of prior filtering surgery. Self-tonometry provides IOP data that supplements in-clinic tonometry and would not be detectable over daytime in-clinic diurnal curves. A subset of patients in whom home tonometry was ordered by their glaucoma clinician because of suspicion of occult IOP elevation demonstrated reproducible IOP elevation outside of the clinic setting. Such patients tended to be younger and male and not to have undergone previous filtering surgery.

A Polygenic Risk Score Predicts Intraocular Pressure Readings Outside Office Hours and Early Morning Spikes as Measured by Home Tonometry

Intraocular pressure (IOP) elevations may occur in early morning or outside office hours and can be missed during routine in-clinic IOP measurements. Such fluctuations or peaks likely contribute to glaucoma progression. We sought to investigate the relationship between an IOP polygenic risk score (PRS) and short-term IOP profile. Cross-sectional study. Four hundred seventy-three eyes from 239 participants with suspected or established primary open-angle glaucoma sampled from 4 outpatient clinics in Australia between August 2016 and December2019. Participants underwent Icare HOME (Icare Oy, Vanda, Finland) tonometer measurements to record IOP 4 times daily for 5 days. Unreliable measurements were excluded. A minimum of 2 days with at least 3 reliable measurements were required. We used a validated IOP PRS derived from 146 IOP-associated variants in a linear regression model adjusted for central corneal thickness and age. Highest recorded early morning IOP and mean IOP within and outside office hours. Early morning IOP spikes were defined by a higher early morning IOP than the maximum in-office hours IOP. Reliable measurements were obtained from 334 eyes of 176 participants (mean age, 64 ± 9 years). Eyes in the highest IOP PRS quintile showed an early morning IOP increase of 4.3 mmHg (95% confidence interval [CI], 1.4-7.3; P= 0.005) and mean increase in IOP outside office hours of 2.7 mmHg (95% CI, 0.61-4.7; P= 0.013) than the lowest quintile, which were significant independently after accounting for a recent in-clinic IOP measured by Goldmann applanation tonometry. Eyes in the highest PRS quintile were 5.4-fold more likely to show early morning IOP spikes than the lowest quintile (odds ratio 95% CI, 1.3-23.6; P= 0.023). A validated IOP PRS was associated with higher early morning IOP and mean IOP outside office hours. These findings support a role for genetic risk prediction of susceptibility to elevated IOP that may not be apparent during in-clinic hours, requiring more detailed clinical phenotyping using home tonometry, the results of which may guide additional interventions to improve IOP control.

A Comparison of Short-Term Intraocular Pressure Fluctuation with Office-Based and Home Tonometry

This study found good agreement between intraocular pressure measured by office-based and home tonometry. There was no difference in mean IOP, but home tonometry enabled measurements outside office-hours identifying greater fluctuation and higher IOP peaks.

This issue of Acta

This issue of Acta

Using Icare HOME tonometry for follow-up of patients with open-angle glaucoma before and after selective laser trabeculoplasty.

Monitoring the results of selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) using a home rebound tonometry. To evaluate the role of Icare HOME tonometry in open-angle glaucoma patients being treated with SLT. A clinic-based prospective case study. Fourteen eyes from 14 patients diagnosed with primary open-angle glaucoma were recruited. The trabecular meshwork of each eye was treated 360° with a frequency-doubled Q-switched Nd:YAG laser. IOP was measured four times a day for a week before and after SLT. On the day of SLT, the patients were required to measure the IOP in the evening to record any IOP spikes. The use of Icare HOME in following up patients post-laser trabeculoplasty without the need for clinic attendance. Icare HOME recorded a significant reduction of 5.12 mmHg in the mean IOP post-SLT (95% confidence interval [CI] 3.75-6.50 mmHg, P < .001). The maximum IOP was also reduced by 6.14 mmHg (95% CI 3.07-9.21, P < .001) with no IOP spikes recorded post-SLT. There was a reduction in IOP fluctuation post-SLT by 1.07 mmHg (95% CI 0.24-1.89 mmHg, P = .021). No adverse effects for using the Icare HOME were reported by the study participants. This methodology could be highly useful for facilitating safe follow-up of patients residing in remote and rural areas, thus reducing healthcare cost with better information on IOP.

Home Tonometry Assists Glaucoma Drainage Device Management in Childhood Glaucoma.

The postoperative management of the nonvalved Baerveldt GDD presents challenges in pediatric patients due to widely variable IOP often occurring perioperatively. We evaluated the use of home tonometry in the management of Baerveldt implants for refractory childhood glaucoma. As part of an ongoing prospective study involving home rebound tonometry, the families of patients receiving Baerveldt implants were trained to use the Icare TA01i rebound tonometer and asked to document IOP, relevant symptoms, and ocular medication changes outside of the clinic setting. Data were analyzed for time to tube-opening, multiple-day fluctuations, and various IOP trends. Clinician response to IOP fluctuations detected by home tonometry was also evaluated. Included were 19 patients (mean age: 16.1±9.6 y) having Baerveldt implantation from 2015 to 2018 by 1 attending physician. Home tonometry detected 92.3% (12/13) of spontaneous tube-openings, which occurred at a mean of 6.0±0.5 weeks. By home tonometry, mean IOP decreased 32.7% (24 vs. 15 mm Hg, P<0.01); 5-day IOP fluctuation decreased from 15 mm Hg preoperatively to 8 mm Hg after tube-opening (P<0.05). Preoperative, postimplantation, and post-tube-opening IOP ranged from 10 to 59, 3 to 61, and 1 to 51 mm Hg, respectively. Home tonometry prompted 94 documented medication changes and validated 1 surgical decision among 14 patients. Home rebound tonometry accurately detected tube-opening and alarming IOP fluctuations, allowing clinicians to promptly and appropriately respond to these events. Home tonometry-augmented GDD management in childhood glaucoma may improve the care of these challenging patients.

Self-monitoring of intraocular pressure using Icare HOME tonometry in clinical practice.

Purpose: To determine the value of self-monitoring of diurnal intraocular pressure (IOP) by Icare Home rebound tonometer in patients with glaucoma and ocular hypertension.Methods: Patients with open-angle glaucoma or ocular hypertension, controlled IOP at office visits, and at least 3 years of follow-up in the glaucoma clinic were included. Progression of glaucoma was based on medical records and defined by documented structural and/or visual field change. Patients were trained to correctly perform self-tonometry and instructed to measure diurnal IOP in a home setting for 3 days. IOP characteristics (mean, peak IOP, fluctuation of IOP as range, and SD of IOP) were documented and compared between the progressive and stable eyes.Results: Ninety-four patients (50 females) with a mean (SD) age of 57.1 (14.7) years were included. Among the 94 eyes from 94 subjects, 72 (76.6%) eyes had primary open-angle glaucoma, ten (10.6%) had pigmentary glaucoma, four (4.3%) had exfoliative glaucoma, and eight (8.5%) eyes had ocular hypertension. Thirty-six eyes showed progression and 58 eyes were stable. Patients with progression were older than those with stable disease (mean (SD) 65.8 (8.4) years vs 51.7 (15.3) years, P<0.001). The progression group had higher average IOP (mean (SD) 15.8 (4.0) mmHg vs 13.3 (3.7) mmHg, P=0.002), peak IOP (mean (SD) 21.8 (5.8) mmHg vs 18.6 (4.8) mmHg, P=0.01), and greater IOP fluctuation range (mean (SD) 11.6 (4.8) vs 9.1 (3.5) mmHg, P=0.011) compared to non-progression group.Conclusion: Self-monitoring of IOP using Icare Home tonometry provides more complete data on variability of IOP to assist in the management of glaucoma.

Home tonometry in childhood glaucoma: clinical indications and physician and parental attitudes

Home rebound tonometry is a beneficial tool for the management of childhood glaucoma, yet is not commonly used. In this study, 29 childhood glaucoma patients were recruited for twice daily home intraocular pressure (IOP) monitoring using an Icare rebound tonometer. Home rebound tonometry data prompted and/or validated glaucoma-related surgery in 16 patients (55%) and medication change in 22 patients (76%). According to survey responses, 84% of parents or patients (n=83) would be interested in home tonometry, and 80% of physicians (n=48) agreed that home tonometry would improve their ability to manage patients; however, only 14% of physicians currently lend tonometers for this purpose, largely due to financial concerns.

Twenty-four hour intraocular pressure measurements and home tonometry.

IOP is the only treatable risk factor contributing to glaucoma and most management and treatment of glaucoma is based on IOP. However, current IOP measurements are limited to office hours and control of glaucoma in many patients would benefit from the ability to monitor IOP diurnally so as not to miss abnormal pressures, which occur outside of office hours Consequently, to improve patient care, the ability to enable accurate and minimally disruptive diurnal IOP monitoring would improve caring for these patients. The studies we selected for this review can be divided into three categories: self-/home-tonometry, continuous invasive intraocular pressure measurements, and continuous noninvasive ocular measurements. The desire to obtain better insight in our patients' true diurnal IOP has led to the development of home-tonometers, in addition to extraocular and intraocular continuous pressure measurement devices. All of the devices have respective advantages and disadvantages, but none to date completely fulfills the goal of providing a true diurnal IOP profile.Video abstracthttp://links.lww.com/COOP/A27.

Home Tonometry—Can We? Should We?

Home Tonometry—Can We? Should We?

Home tonometry in pediatric glaucoma: parental and physician attitudes, and clinical indications

Home tonometry in pediatric glaucoma: parental and physician attitudes, and clinical indications

Icare ONE Home Tonometry in Children With and Without Known Glaucoma.

The Icare ONE (Finland Oy) rebound tonometer may have promise for home tonometry in children with glaucoma. The purpose of this study was: (1) to assess the feasibility of Icare ONE home tonometry in a small number of children with and without glaucoma and (2) to characterize diurnal intraocular pressure (IOP) variations in children with and without glaucoma. Patients were recruited from Duke pediatric ophthalmology clinic. Parents underwent in-clinic training for Icare ONE tonometry. Parents were instructed to record the subject's IOP using Icare ONE at 6 time intervals daily for 10 sequential days. Eight normal subjects (16 eyes) and 10 subjects (10 eyes) with glaucoma were included. All parents successfully performed Icare ONE home tonometry. In-clinic Icare ONE IOP exceeded Goldmann applanation in both groups. Normal subjects (mean age, 11.8 y) had a mean daily IOP range of 4.8 ± 4.6 mm Hg for right eyes and 5.2 ± 1.7 mm Hg for left eyes, and demonstrated relative peaks in the morning and relative troughs in the evening. Subjects with glaucoma (mean age, 12.4 y) had a mean daily IOP range of 8.6 ± 8.2 mm Hg, and demonstrated an even distribution of relative peaks and troughs throughout the day. Icare ONE home tonometry seems feasible in a small number of children. Normal eyes demonstrated smaller daily IOP ranges than glaucomatous eyes. Normal eyes were also more likely to show a relative early morning IOP peak and a late evening IOP trough. It is likely that the limited sampling in this study limits its generalizability to all children with glaucoma or to normal children.

Evaluation of a new rebound tonometer for self-measurement of intraocular pressure

Background/aimsTo compare the accuracy of self-obtained, partner-obtained and trainer-obtained measurements using the handheld Icare Home rebound tonometer with Goldmann applanation tonometry (GAT), and to evaluate the acceptability to subjects of...

An overview of home tonometry and telemetry for intraocular pressure monitoring in humans.

To review the existing technology for self-tonometry and evaluate methods for continuous monitoring of IOP currently undergoing development and clinical trials in humans. Glaucoma is one of the leading causes of blindness worldwide. Current glaucoma therapy is focused primarily on lowering intraocular pressures (IOP). Decisions to modify treatment regiments are primarily based on office IOP. Since IOP fluctuates throughout the day, values obtained in the office may be a poor representation of the patient's disease. IOP measurements outside of the physician's office environment would provide better knowledge of the disease state and allow for better-informed medical decision making. We performed a literature search using Medline and IEEE database for studies investigating technologies that have been developed for continuous 24-hour IOP monitoring. There is currently no technology that has been approved for use to allow for continuous monitoring of IOP fluctuations. New experimental technology being developed and currently undergoing clinical trials has demonstrated potential for changing the diagnosis and management of glaucoma.