a study to assess an automated laser device for direct selective laser trabeculoplasty

Conditions: Open Angle Glaucoma; Ocular Hypertension

Summary: glaucoma is an eye disease that results in damage to the optic nerve that progresses over time. one of the main risk factors in glaucoma is an increase in intraocular pressure, caused by a build-up of fluid in the eye. glaucoma can result in blindness if left untreated and as such it is extremely important to diagnose and treat the condition. selective laser trabeculoplasty (slt) is a laser treatment that facilitates the outflow of fluid from inside the eye. this has the potential of reducing the intraocular pressure within the eye (the main way in which this disease is treated since there is no cure) and may assist in helping to control the progression of this disease. slt (standard treatment) is a technique routinely carried out by glaucoma specialists. it is conducted using a special type of lens (goniolens) that gently sits on the front surface of the eye. the procedure takes approximately 5 minutes in duration. this new treatment, direct selective laser trabeculoplasty (dslt) is performed directly, without there being any need to use a goniolens which sits on the eye, and it is a shorter and simpler technique to conduct when compared to the standard slt technique. the purpose of this study is to assess the hypothesis that the treatment by new automated device for dslt is not worse in comparison with the standard slt and determine that it is effective in reducing intraocular pressure.

glaucoma can result in blindness if left untreated and as such it is extremely important to diagnose and treat the condition. usually doctors treat the first symptoms of glaucoma or ocular hypertension by prescribing eye drops. unfortunately, there can be side effects associated with the use of these eye drops and there are reports of non-compliance due to difficulties in inserting these drops, all of which can impact on how effective this treatment regimen is. the purpose of this study is to assess how well the new automated dslt device for laser treatment of glaucoma or ocular hypertension works in comparison with the standard slt and determine that it is as effective in reducing intraocular pressure. dslt or slt will be performed in the study eye according to the randomization assignment. eligible patients who sign the informed consent will be enrolled at each of the study sites, and undergo a washout (in the case of being medicated). after washout there will be a baseline visit, where continued eligibility is confirmed. following confirmation of continued eligibility, 50% of patients being randomized to each treatment group. randomization will be to a pre-determined randomization list. the un-masked investigator(s) will open the envelope corresponding to the subject id and administer the treatment as indicated by the randomization envelope. the masked ophthalmologist(s), who will perform the follow up, will be masked as to the nature of the treatment the patient underwent. only one eye per participant will be included in the study and they will be treated using either dslt or slt as per the randomized treatment allocation.

Eligibility criteria:
inclusion criteria: 1. age 40 years or older, with visual acuity \> 6/60 in both eyes 2. open angle glaucoma including exfoliative or pigmentary glaucoma or ocular hypertension 3. iop ≥ 22mmhg to ≤35mmhg (after washout of any iop-lowering medications) 4. gonioscopically visible scleral spur for 360 degrees without indentation 5. ability to visualize the peri-limbal sclera for 360 degrees (using a lid speculum) 6. willing and able to participate in the 12-month study, to comply with the study procedures and to adhere to the follow-up schedule 7. participant capable of giving informed consent exclusion criteria: 1. contraindications to conventional laser trabeculoplasty (e.g. corneal abnormalities, etc.) 2. angle closure glaucoma 3. congenital or developmental glaucoma 4. secondary glaucoma except exfoliative or pigmentary glaucoma 5. presence of any peripheral anterior synechiae (pas) in the study eye 6. inability to conduct a reliable visual field (defined as fixation losses, false positives or false negatives greater than 33%) 7. any of the following visual field findings using the humphrey visual field analyzer the sita-standard 24-2 program: 1. a visual field md of worse than -12db 2. greater than or equal to 75% of points depressed below the 5% level and greater than or equal to 50% of points depressed below the 1% level on the pd plot 3. at least 50% of points (i.e 2 or more) within the central 5 degrees with a sensitivity ≤0db on the decibel plot 4. points within the central 5 degrees of fixation with a sensitivity \<15 db in both hemifields on the decibel plot 8. a visual field md of worse than -12db in the fellow eye 9. cup:disc ratio of more than 0.8 10. more than three hypotensive mediations required 11. prior incisional or laser glaucoma surgery (including previous slt) in the study eye 12. prior corneal refractive surgery 13. complicated cataract surgery ≤ 6 months prior to enrollment 14. presence of visually significant cataract in the opinion of the investigator 15. clinically significant disease in either eye as determined by the investigator 16. clinically significant amblyopia in either eye 17. dense pigmentation or haemorrhage in the peri-limbal conjunctiva or anterior sclera 18. women who are pregnant or may become pregnant during the study 19. in the opinion of the investigator the participant might require other ocular surgery within the 12-month follow-up period, unless for further reduction of their iop 20. concurrent treatment with topical, nasal, inhaled or systemic steroids 21. uncontrolled systemic disease that could impact the ability of the participant to attend follow up visits as per the discretion of the investigator 22. participation in another clinical study