Effect of glaucoma medications on 24-hour intraocular pressure-related patterns using a contact lens sensor

Prediction of glaucoma progression by 24-h contact lens sensor profile in patients with normal-tension glaucoma

A single-center prospective cohort study was conducted to investigate whether intraocular pressure (IOP)-related 24-h contact lens sensor (CLS) profile parameters can help predict glaucoma progression in patients with normal-tension glaucoma (NTG). CLS measurements (Triggerfish; SENSIMED, Etagnières, Switzerland) at baseline without medication were performed for 24 h in one eye, following diurnal IOP measurements using Goldmann applanation tonometry at 3-h intervals. Glaucoma progression during the follow-up period of ≥ 2 years was determined based on the Guided Progression Analysis of Humphrey visual fields and/or structural progression using fundus photographs. Among 79 patients (mean values: follow-up periods, 48.1 months; age, 51.5 years; baseline IOP, 14.0 mmHg; mean deviation, - 6.04 dB), 23 showed glaucoma progression. A smaller standard deviation of nocturnal ocular pulse amplitude in the CLS profile, a larger range of diurnal IOP at baseline, and the presence of optic disc hemorrhage (DH) during the study period were significant risk factors for glaucoma progression in the multivariate Cox proportional hazards model (hazard ratio, 0.30/mVeq, 1.23/mmHg, and 4.37/presence of DH; P = 0.016, 0.017, and 0.001, respectively). CLS measurements may be useful for assessing the risk of future glaucoma progression in patients with NTG, providing supplementary information to routine IOP measurements.

Reproducibility of consecutive automated telemetric noctodiurnal IOP profiles as determined by an intraocular implant

BACKGROUND

Intraocular pressure (IOP) monitoring in glaucoma management is evolving with novel devices. We investigated the reproducibility of 24 hour profiles on two consecutive days and after 30 days of self-measurements via telemetric IOP monitoring.

METHODS

Seven primary patients with open-angle glaucoma previously implanted with a telemetric IOP sensor in one eye underwent automatic measurements throughout 24 hours on two consecutive days ('day 1' and 'day 2'). Patients wore an antenna adjacent to the study eye connected to a reader device to record IOP every 5 min. Also, self-measurements in six of seven patients were collected for a period of 30 days. Analysis included calculation of hourly averages to correlate time-pairs of day 1 versus day 2 and the self-measurements vers day 2.

RESULTS

The number of IOP measurements per patient ranged between 151 and 268 on day 1, 175 and 268 on day 2 and 19 and 1236 during 30 days of self-measurements. IOP time-pairs of automatic measurements on day 1 and day 2 were significantly correlated at the group level (R=0.83, p<0.001) and in four individual patients (1, 2, 6 and 7). IOP time-pairs of self-measurements and day 2 were significantly correlated at the group level (R=0.4, p<0.001) and in four individual patients (2, 5, 6 and 7).

CONCLUSIONS

Twenty-four hour automatic measurements of IOP are correlated on consecutive days and, though to a lesser degree, with self-measurements. Therefore a virtual 24-hour IOP curve might be constructed from self-measurements. Both options provide an alternative to frequent in-office IOP measurements.

24-Hour efficacy of single primary selective laser trabeculoplasty versus latanoprost eye drops for Naïve primary open-angle glaucoma and ocular hypertension patients

This prospective, observer-masked, randomized clinical trial was conducted between December 2018 and June 2021 at Eye Hospital, China Academy of Chinese Medical Sciences. A total of 45 glaucoma patients from Beijing, China, were enrolled in this clinical trial to compare the short-term efficacy of primary single-selective laser trabeculoplasty (SLT) to 0.005% latanoprost eye drops for the treatment of 24-h intraocular pressure (IOP) in patients with newly diagnosed primary open angle glaucoma (POAG) and ocular hypertension (OHT). Both SLT and latanoprost significantly decreased mean 24-h IOP and peak IOP, although the latanoprost group effect was more potent when compared to the SLT group (both Ps < 0.05). Compared with the SLT group, the latanoprost group had a significant and stable decrease in IOP after treatment. The latanoprost group had a more pronounced reduction in IOP at weeks 4 and 12 (P < 0.05) but had no difference at week 1 (P = 0.097). As a first-line treatment, both SLT and latanoprost eye drops are effective in newly diagnosed POAG and OHT patients. However, the latanoprost eye drops may be better in decreasing mean and peak 24-h IOP and thus controlling 24-h IOP fluctuation compared to SLT.

Latanoprost eye drops induce conjunctival lymphatic vessel development

AIM

To investigate the effect of latanoprost eye drops on the conjunctival lymphatics.

METHODS

Twenty-four healthy New Zealand White rabbits weighing 1.5 to 2.0 kg were randomly divided into three groups: latanoprost group (n=8) administered with latanoprost eye drops once a day for 2mo, carteolol group (n=8) administered with carteolol eye drops once a day for 2mo, and control group (n=8) without any treatment. The conjunctival tissues in the three groups were extracted to investigate the expression levels of 5'-nucleotidase (5'-Nase) by Western blot, reverse transcription-polymerase chain reaction (RT-PCR), and immunofluorescence staining, respectively.

RESULTS

The protein expression level of 5'-Nase was significantly higher in latanoprost group than carteolol group (F=231.175, P<0.001) and control group (P<0.001), while there was no significant difference between the carteolol group and the control group (P>0.05). The mRNA expression level of 5'-Nase in the latanoprost group was also significantly higher than carteolol group (F=71.169 P<0.005) and control group (P<0.005). The conjunctival lymphatics were positive immunofluorescence stained with the 5'-Nase antibodies in the latanoprost group and not stained in the control group.

CONCLUSION

Latanoprost eye drops can induce conjunctival lymphangiogenesis which may be concerned in clinical implications.

Combined ab-interno trabeculectomy and cataract surgery induces comparable intraocular pressure reduction in supine and sitting positions

AIM

To analyze the therapeutic effect of combined ab-interno trabeculectomy and cataract surgery on intraocular pressure (IOP) levels in supine and sitting postures during a 24-hour IOP profile.

METHODS

Twenty-six eyes of twenty-six patients receiving ab-interno trabeculectomy using electroablation of the trabecular meshwork combined with cataract surgery or stand-alone were included in this retrospective analysis. IOP change during 24-hour IOP profiles within two years postoperatively were analyzed for eyes receiving surgery ("study eyes") and compared to fellow eyes, which had not received surgery. Clinical data including mean sitting IOP (siIOP), mean supine IOP (suIOP) and the number of topical antiglaucomatous medications (TAM) were extracted from patients' files.

RESULTS

Preoperatively, siIOP was 17.6±5.3 mm Hg in study and 17.1±4.7 mm Hg in fellow eyes (P=0.347). Patients were treated with an average of 2.8±1.0 TAM. Best corrected visual acuity (BCVA) was significantly worse in study eyes (P<0.001), visual field function was marginally not significantly different (P=0.057). After surgery 9.6±6.8mo, study eyes had a mean siIOP of 14.5±3.6 mm Hg (IOP reduction: -3.2 mm Hg, P=0.009), a mean suIOP of 18.0±3.5 mm Hg, and an average of 1.3±1.34 TAM (P<0.001), while in fellow eyes, mean siIOP was 16.2±3.4 mm Hg and mean suIOP was 20.5±5.1 mm Hg. Postoperatively, the relative IOP increase between sitting and supine postures was approximately 30% in both study and fellow eyes (P=0.99).

CONCLUSION

IOP after ab-interno trabeculectomy shows a comparable relative reduction in both supine and sitting position. Classical trabeculectomy is known to lower suIOP overproportionally.

Outcome, influence factor and development of CLS measurement in continuous IOP monitoring: A narrative review

A large fluctuation in intraocular pressure (IOP) and a high peak IOP remain the risk factors for progressive visual field loss in patients with glaucoma, which is a leading cause of irreversible blindness. However, IOP measurements during working time cannot provide sufficient information on IOP to guide clinicians in setting IOP target values. Contact lenses are extensively used in ophthalmology to correct the refractive error, and recently, they are serving as platforms for detection and drug delivery. Contact lens sensor (CLS) is a feasible and promising approach to continuously monitor IOP, with superior tolerance, non-invasiveness, and without sleep disturbance. The present work reviewed the associations between progressive course and Triggerfish® CLS outputs as well as the relationship between treatments and Triggerfish® CLS outputs. Moreover, it further summarized state-of-the-art CLS devices of the past decade.

[Dependency of intraocular pressure on body posture in glaucoma patients : New approaches to pathogenesis and treatment]

BACKROUND

Human intraocular pressure (IOP) depends on the position of the head in relation to the body in space. Physiologically, the IOP increases in a lying position compared to an upright posture. Microgravity in space also appears to cause an increase in intraocular pressure, accompanied by other ophthalmological changes, which are summarized under the term spaceflight associated neuro-ocular syndrome (SANS). Bed rest studies are being carried out to investigate the effects of weightlessness on the human body. So here there is an intersection between research into SANS and glaucoma. Increased intraocular pressure remains the most important risk factor for glaucoma development and progression that can be influenced by treatment. The influence of position-dependent IOP fluctuations on glaucoma is still not sufficiently understood.

MATERIALS AND METHODS

A literature search was carried in PubMed on the subject of IOP fluctuations related to posture. Analysis and evaluation of the published study results and a summary of available clinical data.

RESULTS

The increase in IOP when changing from a seated to a lying body position is greater in glaucoma patients with an increase of up to 8.6 mm Hg compared to healthy subjects with an increase up to 5 mm Hg. In small pilot studies the increase in lying IOP in some glaucoma patients and healthy volunteers could be attenuated by elevation of the head by 30%. A lower compartmental pressure in the subarachnoid space has been associated with glaucoma and may represent a risk factor for glaucoma development. Not only the level of IOP but also IOP fluctuations were associated with an increased risk of disease progression.

CONCLUSION

The clinical significance of IOP peaks during sleep on glaucoma is still not sufficiently understood. New methods for continuous IOP measurement offer promising opportunities for further research into the importance of IOP fluctuations related to changes of body and head posture.

Short-Term and Long-Term Variability of Intraocular Pressure Measured with an Intraocular Telemetry Sensor in Patients with Glaucoma

PURPOSE

To evaluate the short-term and long-term variability of intraocular pressure (IOP) in eyes with primary open-angle glaucoma.

DESIGN

Prospective study.

PARTICIPANTS

Twenty-two patients previously implanted with a sulcus-based IOP sensor (EyeMate, Implandata GmbH, Germany).

METHODS

Twenty-two patients previously implanted with the EyeMate were requested to obtain at least 4 IOP measurements daily. Data were grouped according to the eye and the medication so that an eye treated with a particular medication was considered as one group, and the same eye treated with a different medication during the observation period was considered as a different group. A day was divided into 7 periods: night, midnight to 5:59 am; early, 6 am to 7:59 am; morning, 8 am to 10:59 am; noon, 11 am to 1:59 pm; afternoon, 2 pm to 5:59 pm; evening, 6 pm to 8:59 pm; and late, 9 pm to 11:59 pm. Short-term variability during a particular period was defined as the variability in IOP measurements obtained during that period on different days within 3 months of each other. Long-term variability was defined as the variability in IOP measurements obtained during a particular period on different days over a period of 1 year or more. Variability was assessed using intraclass correlation coefficients (ICCs).

RESULTS

The mean age of study participants was 67.8 ± 6.8 years and 36.4% were women. The mean follow-up duration of patients was 19.2 ± 21.3 months (median, 9 months; range, 1-58 months). Overall, 92 860 IOP measurements over 15 811 measurement days were obtained and analyzed during the study period. The number of measurements obtained from each eye ranged from 1 daily to 277 daily. Intraclass correlation coefficients for short-term variability among the 7 periods during the day ranged from 0.52 (morning) to 0.66 (early). Long-term ICCs ranged from 0.29 (night) to 0.51 (late).

CONCLUSIONS

Continual IOP monitoring showed that IOP has moderate short-term and high long-term variability in glaucoma patients. These findings demonstrate that single IOP measurements do not characterize day-to-day variations in IOP. Moreover, they show the importance of continual IOP monitoring in glaucoma patients.

Weekly and seasonal changes of intraocular pressure measured with an implanted intraocular telemetry sensor

Background/Aims

To better understand seasonal and weekday intraocular pressure (IOP) variations, long-term daily IOP measurements were assessed in patients with glaucoma using an intraocular telemetric sensor.

Methods

This prospective, open-label, multicentre observational study analysed the IOP variation patterns in 22 eyes of 22 patients with primary open-angle glaucoma (67.8±6.8 years, 36.4% female) who had undergone placement of an intraocular telemetric sensor at the time of cataract surgery. The telemetric system combines an implantable IOP sensor with a hand-held reading device. Patients were instructed to self-measure their IOP as often as desired, but at least four times daily. Analysis of variance and Tukey multiple-comparison correction were used to assess the statistical significance of average and peak IOP variations between individual weekdays and months.

Results

Each enrolled patient recorded daily IOP measurements for an average duration of 721 days. On average, IOPs were highest on Wednesdays and lowest on Fridays (p=0.002). There were significant variations of IOP throughout the year, and IOP showed a seasonal pattern. Between mid-winter (December–January) and mid-summer months, there was a reduction in mean IOP of 8.1% (-1.55 mm Hg, p<0.05).

Conclusion

This study confirms previously observed seasonal variations of IOP. IOP was significantly higher in winter compared with summer months. Moreover, IOP was lower on Friday than on other days. The explanation for these results is not known.

The Effect of Therapeutic IOP-lowering Interventions on the 24-hour Ocular Dimensional Profile Recorded With a Sensing Contact Lens

PRéCIS:: The 24-hour ocular dimensional profile recorded by a contact lens sensor was affected by intraocular pressure lowering interventions. Among different treatments, incisional surgery had the most significant effect.

PURPOSE

We investigated the effect of different intraocular pressure (IOP)-lowering interventions on contact lens sensor (CLS) parameters and their relationship with Goldmann applanation tonometry (GAT)-measured IOP reduction.

METHODS

Data from reliable CLS recordings performed before and after IOP-lowering interventions were analyzed. Three interventions were evaluated: topical medications, laser trabeculoplasty, and incisional surgery. A set of 115 different CLS parameters were derived from 24-hour curves. We compared before versus after values for each parameter. In addition, linear regression was performed using the percentage change of each CLS parameter as the outcome variable and the type of IOP-lowering procedure as the predictor after adjusting age and race. Finally, we investigated the relationship between changes in CLS parameters and GAT IOP with the Spearman rank correlation coefficient.

RESULTS

A total of 182 eyes of 182 patients were included in the analyses: 60 (33%) topical medications, 69 (38%) laser, and 53 (29%) surgery. The mean GAT IOP change was 3.6±6.5 mm Hg (P<0.001). Overall, more CLS parameters had a significant change after surgery than in the other groups (surgery>laser=drug). Linear regression showed that, for 20 CLS parameters, surgery was the most predictive of greatest percentage change in CLS signals. In all, 11 (9.5%) of the CLS parameters were significantly correlated with GAT changes.

CONCLUSIONS

Incisional glaucoma surgery had a more pronounced effect on GAT and CLS parameters than laser and drugs. The CLS can detect changes in patterns resulting from IOP-lowering interventions beyond daytime GAT IOP. This device could potentially be used to assess treatment efficacy in glaucoma.

Can a contact lens sensor predict the success of trabectome surgery?

PURPOSE

We examined whether a contact lens sensor (CLS) is useful for the postoperative evaluation of trabectome surgery. We investigated the correlations between the outcomes of trabectome surgery and the output of a CLS.

METHODS

We examined 24 consecutive eyes of patients with pseudo-exfoliation glaucoma. In each eye, the intraocular pressure (IOP) fluctuations over 24 h were measured with the SENSIMED Triggerfish CLS before and at 3 months after the trabectome surgery. We divided the patients into success (n = 12 eyes) and failure (n = 12 eyes) groups; success was defined as a postoperative IOP level ≤ 21 mmHg plus an IOP reduction ≥ 20% relative to the preoperative IOP value with or without anti-glaucoma medications. We investigated CLS parameters that correlate with surgical outcomes by performing a Cox hazard regression analysis. We determined the maximum value, minimum value, and range of IOP fluctuation as CLS parameters.

RESULTS

The mean follow-up period was 38.0 ± 3.0 months. The success rate was 50%. The postoperative range of IOP fluctuation during the nocturnal period with the CLS was significantly correlated with the surgical results (p = 0.024).

CONCLUSIONS

A smaller range of IOP fluctuation was significantly correlated with better surgical outcomes. We were able to predict the surgical success after trabectome surgery at 3 months using the CLS. Thus, CLS results could be a new surgical evaluation parameter.

Once Daily Pregabalin Eye Drops for Management of Glaucoma

Elevated intraocular pressure (IOP) is the most significant risk factor contributing to visual field loss in glaucoma. Unfortunately, the deficiencies associated with current therapies have resulted in reduced efficacy, several daily dosings, and poor patient compliance. Previously, we identified the calcium voltage-gated channel auxiliary subunit alpha2delta 1 gene (Cacna2d1) as a modulator of IOP and demonstrated that pregabalin, a drug with high affinity and selectivity for CACNA2D1, lowered IOP in a dose-dependent manner. Unfortunately, IOP returned to baseline at 6 h after dosing. In the current study, we develop a once daily topical pregabalin-loaded multiple water-in-oil-in-water microemulsion formulation to improve drug efficacy. We characterize our formulations using multiple in vitro and in vivo evaluations. Our lead formulation provides continuous release of pregabalin for up to 24 h. Because of its miniscule droplet size (<20 nm), our microemulsion has a transparent appearance and should not blur vision. It is also stable at one month of storage at temperatures ranging from 5 to 40 °C. Our formulation is nontoxic, as illustrated by a cell toxicity study and slit-lamp biomicroscopic exams. CACNA2D1 is highly expressed in both the ciliary body and the trabecular meshwork, where it functions to modulate IOP. A single drop of our lead pregabalin formulation reduces IOP by greater than 40%, which does not return to baseline until >30 h post-application. Although there were no significant differences in the amplitude of IOP reduction between the formulations we tested, a significant difference was clearly observed in their duration of action. Our multilayered microemulsion is a promising carrier that sustains the release and prolongs the duration of action of pregabalin, a proposed glaucoma therapeutic.

Role of 24-Hour Intraocular Pressure Monitoring in Glaucoma Management

Glaucoma is the leading cause of irreversible blindness worldwide and the prevalence is on the rising trend. Intraocular pressure (IOP) reduction is the mainstay of treatment. The current practice of IOP monitoring is based on spot measurements during clinic visits during office hours. However, there are up to 50% of glaucoma patients who had normal initial IOP, while some treated patients continued to have progressive glaucomatous optic nerve damage even with a low IOP. Recent studies have shown that the IOP of glaucoma patients fluctuated during the day with different patterns, and some of them had peak IOP outside office hours. These findings provided us with new insights on the role of 24-hour IOP monitoring in managing normal tension glaucoma and patients with progressive deterioration despite apparently well-controlled IOP. Nevertheless, results to date are rather inconsistent, and there is no consensus yet. In this review, we briefly highlighted the current modalities of 24-hour IOP monitoring and summarized the characteristic 24-hour IOP pattern and the clinical relevance of IOP parameters in predicting glaucomatous progression in different glaucoma subtypes. We also discussed the therapeutic efficacy of current glaucoma treatment modalities with respect to the mentioned 24-hour IOP profiles, so as to strengthen the role of 24-hour IOP monitoring in identifying and stratifying the risks of progression in glaucoma patients, as well as optimizing treatments according to their IOP profiles.

Fluctuations of the Intraocular Pressure in Medically Versus Surgically Treated Glaucoma Patients by a Contact Lens Sensor

PURPOSE

To compare fluctuations in intraocular pressure (IOP) in medically vs surgically treated glaucoma patients.

DESIGN

Prospective, nonrandomized case series.

METHODS

IOP-related fluctuations were measured for 24 hours using a contact lens sensor (CLS).

SUBJECTS

We performed monitoring with CLS in 91 eyes of 77 patients; 59 eyes were receiving ocular hypotensive medication and had no previous history of glaucoma surgery (medical group), while 32 eyes with open-angle glaucoma (OAG) had previously undergone glaucoma surgery (surgical group).

MAIN OUTCOME MEASURES

The amplitude, expressed as an indicator of the IOP-related fluctuation, and the presence of a nocturnal acrophase. We also identified maximum and minimum IOP-related values for each patient.

RESULTS

The mean (standard deviation) amplitude of IOP-related CLS signal in the group of surgically treated eyes was 100 (41) mV eq, while in the medically treated group it was 131 (69) mV eq (difference: P = .010). We found that 42.9% of the surgically treated but only 13.8% of the medically treated glaucoma group exhibited an absence of nocturnal acrophase (difference: P = .011). The maximum and minimum IOP-related values for the medical group were statistically higher than the surgical group (P = .001 and P = .006, respectively).

CONCLUSIONS

IOP-related fluctuations were larger in eyes with medically treated glaucoma than in those with surgically treated glaucoma. A significantly larger fraction of the surgical group exhibited an absence of nocturnal acrophase compared to the medically treated group.

Twenty-Four-Hour Contact Lens Sensor Monitoring of Aqueous Humor Dynamics in Surgically or Medically Treated Glaucoma Patients

Aim

This study assessed the 24 h circadian rhythm of intraocular pressure (IOP) using a contact lens sensor in three groups of patients with open-angle glaucoma.

Methods

This study was a monocentric, cross-sectional, nonrandomized, prospective, pilot study. Eighty-nine patients were enrolled: 29 patients previously underwent an Ex-PRESS mini glaucoma device procedure (Group 1), 28 patients previously underwent Hydrus microstent implantation (Group 2), and 32 patients were currently being treated medically for primary open-angle glaucoma (Group 3). Circadian rhythm patterns were considered with five circadian indicators: fluctuation ranges, maximum, minimum, acrophase (time of peak value), and bathyphase (time of trough value). A two-tailed Mann–Whitney U-test was used to evaluate differences between groups.

Results

All subjects exhibited a circadian rhythm and a nocturnal pattern. The signal fluctuation range was significantly smaller in the surgical groups than in the medically treated group (Group 1 vs. Group 3, p=0.003; Group 2 vs. Group 3, p=0.010). Subjects who underwent the Ex-PRESS procedure (Group 1) exhibited significant differences compared with the drug therapy group (Group 3) with regard to the minimum value (p=0.015), acrophase (p=0.009), and bathyphase (p=0.002). The other circadian indicators were not significantly different among groups.

Conclusions

Patients who underwent IOP-lowering surgery had an intrinsic nyctohemeral rhythm. Both surgical procedures, Ex-PRESS and Hydrus, were associated with smaller signal fluctuations compared with medical treatment.

Diurnal and 24-h Intraocular Pressures in Glaucoma: Monitoring Strategies and Impact on Prognosis and Treatment

The present review casts a critical eye on intraocular pressure (IOP) monitoring and its value in current and future glaucoma care. Crucially, IOP is not fixed, but varies considerably during the 24-h cycle and between one visit and another. Consequently, a single IOP measurement during so-called office hours is insufficient to characterize the real IOP pathology of a patient with glaucoma. To date IOP remains the principal and only modifiable risk factor for the development and progression of glaucoma. Only by evaluating IOP characteristics (mean, peak and fluctuation of IOP) at diagnosis and after IOP-lowering interventions can we appreciate the true efficacy of therapy. Unfortunately, a major limiting factor in glaucoma management is lack of robust IOP data collection. Treatment decisions, advancement of therapy and even surgery are often reached on the basis of limited IOP evidence. Clearly, there is much room to enhance our decision-making and to develop new algorithms for everyday practice. The precise way in which daytime IOP readings can be used as predictors of night-time or 24-h IOP characteristics remains to be determined. In practice it is important to identify those at-risk glaucoma patients for whom a complete 24-h curve is necessary and to distinguish them from those for whom a daytime curve consisting of three IOP measurements (at 10:00, 14:00 and 18:00) would suffice. By employing a staged approach in determining the amount of IOP evidence needed and the rigour required for our monitoring approach for the individual patient, our decisions will be based on more comprehensive data, while at the same time this will optimize use of resources. The patient’s clinical picture should be the main factor that determines which method of IOP monitoring is most appropriate. A diurnal or ideally a 24-h IOP curve will positively impact the management of glaucoma patients who show functional/anatomical progression, despite an apparently acceptable IOP in the clinic. The potential impact of nocturnal IOP elevation remains poorly investigated. The ideal solution in the future is the development of non-invasive methods for obtaining continuous, Goldmann equivalent IOP data on all patients prior to key treatment decisions. Moreover, an important area of future research is to establish the precise relationship between 24-h IOP characteristics and glaucoma progression.

Innovative Development of Contact Lenses

Contact lenses have been a common means of vision correction for more than half a century. Recent developments have raised the possibility that the next few decades will see a considerable broadening of the range of applications for contact lenses, with associated expansions in the number and type of individuals who consider them a valuable option. The novel applications of contact lenses include treatment platforms for myopic progression, biosensors, and ocular drug delivery. Orthokeratology has shown the most consistent treatment for myopia control with the least side effects. Recent work has resulted in commercialization of a device to monitor intraocular pressure for up to 24 hours, and extensive efforts are underway to develop a contact lens sensor capable of continuous glucose tear film monitoring for the management of diabetes. Other studies on drug-eluting contact lenses have focused on increasing the release duration through molecular imprinting, use of vitamin E, and increased drug binding to polymers by sandwiching a poly (lactic-co-glycolic acid) layer in the lens. This review demonstrates the potential for contact lenses to provide novel opportunities for refractive management, diagnosis, and management of diseases.

Moving From Clinic to Home: What the Future Holds for Ophthalmic Telemedicine

PURPOSE

To describe the expanding role of telemedicine in healthcare, the key criteria required for a successful device and program implementation, and the current and future role of home monitoring in ophthalmology.

DESIGN

Expert perspective.

METHODS

Analysis with real-world interpretation of home monitoring technologies, including current adoption barriers and expanded future demands based on demographic and market forces.

RESULTS

Remote patient monitoring represents a paradigm shift in the way physicians care for patients. Success depends on meeting several criteria, among which are a recognized value proposition to the physician, robust device performance validation, ease of use for the patient, reliability of connectivity, safe and secure data transmission, and economic feasibility. Ophthalmic diseases, such as age-related macular degeneration, glaucoma, and diabetic retinopathy, are ideal candidates for home monitoring practice integration. Established home monitoring technology is already facilitating early detection and improved visual outcomes for patients with age-related macular degeneration. Future innovation currently underway or on the horizon will continue to evolve and expand the footprint of telemedicine within ophthalmology.

CONCLUSION

Home monitoring has the potential to enhance the patient-physician relationship and to positively impact visual acuity outcomes in ophthalmic diseases. Advances in technology, demographic shifts, market changes, and patient demand for personalized medicine will require physicians to embrace technology in new and diverse ways, perhaps facilitating widespread adoption of home monitoring technology platforms.

iDrugs and iDevices Discovery Research: Preclinical Assays, Techniques, and Animal Model Studies for Ocular Hypotensives and Neuroprotectants

Discovery ophthalmic research is centered around delineating the molecular and cellular basis of ocular diseases and finding and exploiting molecular and genetic pathways associated with them. From such studies it is possible to determine suitable intervention points to address the disease process and hopefully to discover therapeutics to treat them. An investigational new drug (IND) filing for a new small-molecule drug, peptide, antibody, genetic treatment, or a device with global health authorities requires a number of preclinical studies to provide necessary safety and efficacy data. Specific regulatory elements needed for such IND-enabling studies are beyond the scope of this article. However, to enhance the overall data packages for such entities and permit high-quality foundation-building publications for medical affairs, additional research and development studies are always desirable. This review aims to provide examples of some target localization/verification, ocular drug discovery processes, and mechanistic and portfolio-enhancing exploratory investigations for candidate drugs and devices for the treatment of ocular hypertension and glaucomatous optic neuropathy (neurodegeneration of retinal ganglion cells and their axons). Examples of compound screening assays, use of various technologies and techniques, deployment of animal models, and data obtained from such studies are also presented.

24-h monitoring devices and nyctohemeral rhythms of intraocular pressure

Intraocular pressure (IOP) is not a fixed value and varies over both the short term and periods lasting several months or years. In particular, IOP is known to vary throughout the 24-h period of a day, defined as a nyctohemeral rhythm in humans. In clinical practice, it is crucial to evaluate the changes in IOP over 24 h in several situations, including the diagnosis of ocular hypertension and glaucoma (IOP is often higher at night) and to optimize the therapeutic management of glaucoma. Until recently, all evaluations of 24-h IOP rhythm were performed using repeated IOP measurements, requiring individuals to be awakened for nocturnal measurements. This method may be imperfect, because it is not physiologic and disturbs the sleep architecture, and also because it provides a limited number of time point measurements not sufficient to finely asses IOP changes. These limitations may have biased previous descriptions of physiological IOP rhythm. Recently, extraocular and intraocular devices integrating a pressure sensor for continuous IOP monitoring have been developed and are available for use in humans. The objective of this article is to present the contributions of these new 24-h monitoring devices for the study of the nyctohemeral rhythms. In healthy subjects and untreated glaucoma subjects, a nyctohemeral rhythm is consistently found and frequently characterized by a mean diurnal IOP lower than the mean nocturnal IOP, with a diurnal bathyphase - usually in the middle or at the end of the afternoon - and a nocturnal acrophase, usually in the middle or at the end of the night.

Systematic Review of Current Devices for 24-h Intraocular Pressure Monitoring

Glaucoma is a common optic neuropathy that can lead to irreversible vision loss, and intraocular pressure (IOP) is the only known modifiable risk factor. The primary method of treating glaucoma involves lowering IOP using medications, laser and/or invasive surgery. Currently, we rely on in-office measurements of IOP to assess diurnal variation and to define successful management of disease. These measurements only convey a fraction of a patient's circadian IOP pattern and may frequently miss peak IOP levels. There is an unmet need for a reliable and accurate device for 24-h IOP monitoring. The 24-h IOP monitoring devices that are currently available and in development fall into three main categories: self-monitoring, temporary continuous monitoring, and permanent continuous monitoring. This article is a systematic review of current and future technologies for measuring IOP over a 24-h period.

The Application of a Contact Lens Sensor in Detecting 24-Hour Intraocular Pressure-Related Patterns

Glaucoma is one of the leading causes of blindness worldwide. Recent studies suggest that intraocular pressure (IOP) fluctuations, peaks, and rhythm are important factors in disease advancement. Yet, current glaucoma management remains hinged on single IOP measurements during clinic hours. To overcome this limitation, 24-hour IOP monitoring devices have been employed and include self-tonometry, permanent IOP, and temporary IOP monitoring. This review discusses each IOP measuring strategy and focuses on the recently FDA-approved contact lens sensor (CLS). The CLS records IOP-related ocular patterns for 24 hours continuously. Using the CLS, IOP-related parameters have been found to be associated with the rate of visual field progression in primary open-angle glaucoma, disease progression in primary angle-closure glaucoma, and various clinical variables in ocular hypertension. The CLS has been used to quantify blink rate and limbal strain and measure the circadian rhythm in a variety of disease states including normal-tension glaucoma and thyroid eye disease. The effects of various IOP-lowering interventions were also characterized using the CLS. CLS provides a unique, safe, and well-tolerated way to study IOP-related patterns in a wide range of disease states. IOP-related patterns may help identify patients most at risk for disease progression and assist with the development of tailored treatments.