Different Glaucoma Treatments Effect on Intraocular Pressure Fluctuation With Postural Change in Eyes With Open-angle Glaucoma

Study Overview
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Brief Summary
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The purpose of this study is to investigate the effect of trabeculectomy, glaucoma drainage devices, cyclophotocoagulation and ocular hypotensive eye-drops on IOP elevation with postural change from the sitting to supine positions in eyes with open-angle glaucoma. Patients will be assigned to the different study groups according to their past ocular history. Interventions are similar to all study group and no medical therapy alteration will be made.

Detailed Description
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Visual impairment and blindness due to chronic progressive optic neuropathy developing from glaucoma are major health problems worldwide. Glaucoma is a progressive, potentially blinding disease, in which the only modifiable risk factor in intraocular pressure. In a significant proportion of patients, the disease progresses despite apparent IOP control(1-3). One factor which may explain some of this discrepancy is a fluctuation of the IOP during the day, which may be missed in a single visit to the ophthalmologist(4). Although this fluctuation depends to some degree on daily biologic rhythms and the specific type of glaucoma, a constant significant factor responsible for this effect is the IOP-dependent changes of body posture, from sitting or standing to lying down(5). Older studies have shown IOP postural changes in the range of 4-6 mmHg(6-8). Seeing how a typical patient may spend as much as a third of his life in the supine position, knowledge of IOP in this position, and its control, are of great importance in decreasing the chance for irreversible optic nerve damage. Several studies of Liu JH(9-11) have investigated the effect of hypotensive drops on nocturnal IOP. While prostaglandin analogues (PGA) and carbonic anhydrase inhibitors (CAI) seemed to have a significant nocturnal IOP lowering effect, the effect seen with beta blockers and alpha agonists was minimal. Mansouri et al.(12) recently showed that PGA seem to ﬂatten the IOP-related increase when moving from the sitting to the supine position at nocturnal period, without effecting other circadian IOP-related patterns. Hirooka Kazuyuki investigated the effect of trabeculectomy on the IOP fluctuations caused by postural changes(13-14). He showed that successful trabeculectomy, which didn't require needling, have significantly decreased the posture-induced IOP changes to less than 3 mmHg. To the best of our knowledge there is no data regarding the effect of glaucoma drainage devices and cyclophotocoagulation on supine IOP. The purpose of this study is to investigate the effect of different IOP lowering methods, including trabeculectomy, glaucoma drainage devices, cyclophotocoagulation and ocular hypotensive eye-drops on IOP with postural change from the sitting to supine positions in eyes with open-angle glaucoma.

Official Title
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The Effect of Trabeculectomy, Glaucoma Drainage Device, Cyclophotocoagulation, and Ocular Hypotensive Eye-drops on Intraocular Pressure Fluctuation With Postural Change in Eyes With Open-angle Glaucoma

Conditions
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Open Angle Glaucoma

Intervention / Treatment
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* Device: Goldmann tonometer
* Device: Pneumatonometer
* Device: Tonopen XL
* Device: ICare rebound tonometer


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: OAG patients Ocular Hypertension (OHT) patients Healthy subjects, without any ocular pathology (except for refraction errors, past cataract surgery, strabismus or amblyopia). Exclusion Criteria: Other intraocular surgeries within the past 3 months Illness effecting episcleral venous pressure, such as superior vena cava syndrome, thyroid eye disease, orbital masses Patients who are unable to maintain supine position for 15 minutes Corneal abnormalities: epithelial pathologies, corneal infection, corneal erosions, corneal scars, keratoconus, S/P corneal transplantation (lamellar/full thickness) Hypersensitivity to oxybuprocaine hydrochloride

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 95 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Trabeculectomy<br>Subjects with OAG s/p Trabeculectomy. IOP measurement in different positions. | Device: Goldmann tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Pneumatonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Tonopen XL<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: ICare rebound tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>|
| Ahmed Glaucoma Valve implantation<br>Subjects with OAG s/p Ahmed valve implantation. IOP measurement in different positions. | Device: Goldmann tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Pneumatonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Tonopen XL<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: ICare rebound tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>|
| Cyclophotocoagulation<br>Subjects with OAG s/p Cyclophotocoagulation. IOP measurement in different positions. | Device: Goldmann tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Pneumatonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Tonopen XL<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: ICare rebound tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>|
| Ocular hypotensive eye drops<br>Subjects with OAG treated with ocular hypotensive eye drops and no ocular surgical hypotensive treatments. IOP measurement in different positions. | Device: Goldmann tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Pneumatonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Tonopen XL<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: ICare rebound tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>|
| Ocular Hypertension<br>Subjects with no evidence of glaucomatous damage, but with IOP measurements above 21 mmHg.. IOP measurement in different positions. | Device: Goldmann tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Pneumatonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Tonopen XL<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: ICare rebound tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>|
| Control<br>Subjects with healthy eyes, apart for refraction errors, post cataract surgery, strabismus or amblyopia. IOP measurement in different positions. | Device: Goldmann tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Pneumatonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: Tonopen XL<br>* IOP measurement in the sitting position and lateral decubitus<br>Device: ICare rebound tonometer<br>* IOP measurement in the sitting position and lateral decubitus<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measurements of Intra Ocular Pressure Fluctuation with Postural Change in Eyes with Open-angle Glaucoma and Ocular Hypertension, compared to healthy subjects | Interventions are similar for all study groups: The subject will be instructed to stay in a sitting position for 5 minutes. A topical anesthetic eye drop (oxybuprocaine hydrochloride 0.4%) will then be installed in the study eye (necessary procedure made in all IOP examinations as a regular procedure) and the IOP will be measured, in the following order by 4 tonometers: Goldmann tonometer, Pneumatonometer, Tonopen XL, ICare rebound tonometer. The subject will then lie supine for 5 minutes, afterwards will turn to the lateral decubitus position and IOP will be measured again using the same tonometers in the same manner. The difference between IOP in the sitting and lying body positions will be assessed and compared to the control group. | Change from baseline 5 minutes following position change | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Glaucoma, Open Angle Glaucoma, Intra Ocular Pressure, Ocular Hypotensive Drops, Trabeculectomy, Cyclophotocoagulation, Glaucoma Drainage Device