Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation in Uncontrolled Glaucoma

Glaucoma Clinical Trial

Official title:

Treatment Outcomes of MicroPulse Trans-scleral Cyclophotocoagulation (mTSCPC) in Uncontrolled Glaucoma at the University of Montreal Hospital Center (CHUM)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03187418
• Other study ID #: CE16.351
• Status: Completed
• Phase: N/A
• Start date: June 19, 2017
• Est. completion date: February 15, 2020

Study information

• Verified date: August 2020
• Source: Centre hospitalier de l'Université de Montréal (CHUM)
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The goal of this study is to evaluate the efficacy and safety of the novel form of trans-scleral cyclophotocoagulation using micropulse diode laser and trans-pars plana treatment (Micropulse TSCPC, mTSCPC MP3, IRIDEX CYCLO G6™ Glaucoma Laser System, CA, USA) in adults for the treatment of uncontrolled glaucoma.

Description:

Cyclophotocoagulation (CPC) is a type of cycloablation using laser to treat glaucoma. It involves ciliary body destruction by targeting the ciliary epithelium and stroma, resulting in a reduction in aqueous secretion and hence intraocular pressure. This strategy is effective for all forms of glaucoma.

Traditional trans-scleral cyclophotocoagulation (TSCPC) achieve its cyclodestructive action by using continuous diode laser to target the melanin in the pigmented ciliary body epithelium. However, the continuous mode has been shown to cause significant collateral tissue damage to adjacent non-pigmented structures including the ciliary stroma and ciliary muscle. Traditional TSCPC may therefore be associated with serious complications including uveitis, visual deterioration, chronic hypotony, and others.

More recently, a micropulse delivery mode of diode laser (Micropulse TSCPC, mTSCPC) has been used to treat glaucoma by ablating the ciliary processes and reduce aqueous humor production with more selective targeting and less collateral damage. In contrast to conventional laser delivery where a continuous flow of high intensity energy is delivered, micropulse laser application delivers a series of repetitive short pulses of energy with rest periods in between pulses. Only a few studies have described the outcomes of this novel glaucoma therapy, showing mTSCPC to have comparable efficacy with fewer side effects when compared with traditional continuous wave mode diode laser delivery.This improved side effect profile has the potential to make mTSCPC an earlier therapeutic option instead of reserving it exclusively for end-stage refractory eyes.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 52
• Est. completion date: February 15, 2020
• Est. primary completion date: February 15, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Patients of either sex and any race aged 18 years old and above.

• Followed by a glaucoma subspecialist at University of Montreal Hospital Center.

• Intraocular pressure (IOP) above target and unresponsive to maximal tolerated medical therapy with or without previous surgical intervention.

1. mild glaucoma: IOP > 18 mmHg

2. moderate glaucoma: IOP > 15 mmHg

3. advanced glaucoma: IOP > 12 mmHg

• Considered poor candidates for additional filtering surgery or implantation of glaucoma drainage devices.

Exclusion Criteria:

• Patients unable to give informed consent.

• Patients with significant scleral thinning, defined as thinning of more than one clock hour noticed on scleral transillumination.

• Ocular infection or inflammation in the study eye in the 2 months prior to enrolment.

• Intraocular surgery in the study eye in the 2 months prior to enrolment.

Related Conditions & MeSH terms

• Glaucoma
• Glaucoma and Ocular Hypertension
• Glaucoma Eye
• Glaucoma Secondary
• Glaucoma, Angle-Closure
• Glaucoma, Neovascular
• Glaucoma, Open-Angle
• Glaucoma, Uncompensated
• Ocular Hypertension

Intervention

Device:
• MicroPulse® P3 Glaucoma Device (MP3)
Laser settings will be programmed as follows: power-2000mW-2500mW (average 2000mW) of 810nm infrared diode laser set on micropulse delivery mode; micropulse "on" time-0.5ms; micropulse "off" time-1.1ms; and duty cycle (proportion of each cycle during which the laser is on)-31.33 %. The laser probe will be applied in a continuous sliding or painting motion from 9:30 to 2:30 and from 3:30 to 8:30. The probe will be applied perpendicular to the limbus with the edge directly on the limbus at all times (fiberoptic tip at 3 mm posterior to the limbus). The laser will be delivered over 360° for 160-320s. Treatment duration will be adjusted based on iris color and glaucoma severity (mild glaucoma: 160s, moderate glaucoma: 240s, advanced glaucoma: 240-320s).

Locations

Country	Name	City	State
Canada	Centre Hospitalier de l'Université de Montréal (CHUM)	Montréal	Quebec

Sponsors (1)

Lead Sponsor	Collaborator
Centre hospitalier de l'Université de Montréal (CHUM)

Country where clinical trial is conducted

Canada, 

References & Publications (28)

Agarwal HC, Gupta V, Sihota R. Evaluation of contact versus non-contact diode laser cyclophotocoagulation for refractory glaucomas using similar energy settings. Clin Exp Ophthalmol. 2004 Feb;32(1):33-8. — View Citation

Aquino MC, Barton K, Tan AM, Sng C, Li X, Loon SC, Chew PT. Micropulse versus continuous wave transscleral diode cyclophotocoagulation in refractory glaucoma: a randomized exploratory study. Clin Exp Ophthalmol. 2015 Jan-Feb;43(1):40-6. doi: 10.1111/ceo.12360. Epub 2014 Jun 21. — View Citation

Berger JW. Thermal modelling of micropulsed diode laser retinal photocoagulation. Lasers Surg Med. 1997;20(4):409-15. — View Citation

Bloom PA, Tsai JC, Sharma K, Miller MH, Rice NS, Hitchings RA, Khaw PT. "Cyclodiode". Trans-scleral diode laser cyclophotocoagulation in the treatment of advanced refractory glaucoma. Ophthalmology. 1997 Sep;104(9):1508-19; discussion 1519-20. — View Citation

Desmettre TJ, Mordon SR, Buzawa DM, Mainster MA. Micropulse and continuous wave diode retinal photocoagulation: visible and subvisible lesion parameters. Br J Ophthalmol. 2006 Jun;90(6):709-12. Epub 2006 Mar 10. — View Citation

Egbert PR, Fiadoyor S, Budenz DL, Dadzie P, Byrd S. Diode laser transscleral cyclophotocoagulation as a primary surgical treatment for primary open-angle glaucoma. Arch Ophthalmol. 2001 Mar;119(3):345-50. — View Citation

Hauber FA, Scherer WJ. Influence of total energy delivery on success rate after contact diode laser transscleral cyclophotocoagulation: a retrospective case review and meta-analysis. J Glaucoma. 2002 Aug;11(4):329-33. — View Citation

Kosoko O, Gaasterland DE, Pollack IP, Enger CL. Long-term outcome of initial ciliary ablation with contact diode laser transscleral cyclophotocoagulation for severe glaucoma. The Diode Laser Ciliary Ablation Study Group. Ophthalmology. 1996 Aug;103(8):1294-302. — View Citation

Kuchar S, Moster MR, Reamer CB, Waisbourd M. Treatment outcomes of micropulse transscleral cyclophotocoagulation in advanced glaucoma. Lasers Med Sci. 2016 Feb;31(2):393-6. doi: 10.1007/s10103-015-1856-9. Epub 2015 Dec 29. — View Citation

Laursen ML, Moeller F, Sander B, Sjoelie AK. Subthreshold micropulse diode laser treatment in diabetic macular oedema. Br J Ophthalmol. 2004 Sep;88(9):1173-9. — View Citation

Leszczynski R, Gierek-Lapinska A, Forminska - Kapuscik M. Transscleral cyclophotocoagulation in the treatment of secondary glaucoma. Med Sci Monit. 2004 Sep;10(9):CR542-8. Epub 2004 Aug 20. — View Citation

Meyer JJ, Lawrence SD. What's new in laser treatment for glaucoma? Curr Opin Ophthalmol. 2012 Mar;23(2):111-7. doi: 10.1097/ICU.0b013e32834f1887. Review. — View Citation

Mistlberger A, Liebmann JM, Tschiderer H, Ritch R, Ruckhofer J, Grabner G. Diode laser transscleral cyclophotocoagulation for refractory glaucoma. J Glaucoma. 2001 Aug;10(4):288-93. — View Citation

Moorman CM, Hamilton AM. Clinical applications of the MicroPulse diode laser. Eye (Lond). 1999 Apr;13 ( Pt 2):145-50. — View Citation

Murphy CC, Burnett CA, Spry PG, Broadway DC, Diamond JP. A two centre study of the dose-response relation for transscleral diode laser cyclophotocoagulation in refractory glaucoma. Br J Ophthalmol. 2003 Oct;87(10):1252-7. — View Citation

Nguyen QH. Primary surgical management refractory glaucoma: tubes as initial surgery. Curr Opin Ophthalmol. 2009 Mar;20(2):122-5. doi: 10.1097/ICU.0b013e32831da828. Review. — View Citation

Oguri A, Takahashi E, Tomita G, Yamamoto T, Jikihara S, Kitazawa Y. Transscleral cyclophotocoagulation with the diode laser for neovascular glaucoma. Ophthalmic Surg Lasers. 1998 Sep;29(9):722-7. — View Citation

Pantcheva MB, Kahook MY, Schuman JS, Rubin MW, Noecker RJ. Comparison of acute structural and histopathological changes of the porcine ciliary processes after endoscopic cyclophotocoagulation and transscleral cyclophotocoagulation. Clin Exp Ophthalmol. 2007 Apr;35(3):270-4. — View Citation

Parodi MB, Spasse S, Iacono P, Di Stefano G, Canziani T, Ravalico G. Subthreshold grid laser treatment of macular edema secondary to branch retinal vein occlusion with micropulse infrared (810 nanometer) diode laser. Ophthalmology. 2006 Dec;113(12):2237-42. Epub 2006 Sep 25. — View Citation

Pollack JS, Kim JE, Pulido JS, Burke JM. Tissue effects of subclinical diode laser treatment of the retina. Arch Ophthalmol. 1998 Dec;116(12):1633-9. — View Citation

Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and 2020. Br J Ophthalmol. 2006 Mar;90(3):262-7. — View Citation

Rotchford AP, Jayasawal R, Madhusudhan S, Ho S, King AJ, Vernon SA. Transscleral diode laser cycloablation in patients with good vision. Br J Ophthalmol. 2010 Sep;94(9):1180-3. doi: 10.1136/bjo.2008.145565. Epub 2010 Jun 24. — View Citation

Schlote T, Derse M, Rassmann K, Nicaeus T, Dietz K, Thiel HJ. Efficacy and safety of contact transscleral diode laser cyclophotocoagulation for advanced glaucoma. J Glaucoma. 2001 Aug;10(4):294-301. — View Citation

Schlote T, Derse M, Zierhut M. Transscleral diode laser cyclophotocoagulation for the treatment of refractory glaucoma secondary to inflammatory eye diseases. Br J Ophthalmol. 2000 Sep;84(9):999-1003. — View Citation

Sivaprasad S, Sandhu R, Tandon A, Sayed-Ahmed K, McHugh DA. Subthreshold micropulse diode laser photocoagulation for clinically significant diabetic macular oedema: a three-year follow up. Clin Exp Ophthalmol. 2007 Sep-Oct;35(7):640-4. — View Citation

Tan AM, Chockalingam M, Aquino MC, Lim ZI, See JL, Chew PT. Micropulse transscleral diode laser cyclophotocoagulation in the treatment of refractory glaucoma. Clin Exp Ophthalmol. 2010 Apr;38(3):266-72. doi: 10.1111/j.1442-9071.2010.02238.x. — View Citation

Tham YC, Li X, Wong TY, Quigley HA, Aung T, Cheng CY. Global prevalence of glaucoma and projections of glaucoma burden through 2040: a systematic review and meta-analysis. Ophthalmology. 2014 Nov;121(11):2081-90. doi: 10.1016/j.ophtha.2014.05.013. Epub 2014 Jun 26. Review. — View Citation

Vernon SA, Koppens JM, Menon GJ, Negi AK. Diode laser cycloablation in adult glaucoma: long-term results of a standard protocol and review of current literature. Clin Exp Ophthalmol. 2006 Jul;34(5):411-20. Review. — View Citation

* Note: There are 28 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Intraocular Pressure (IOP)	In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer	18 months
Secondary	Intraocular Pressure (IOP)	In millimeters of mercury (mmHg), measured with the Goldmann applanation tonometer	1 week, 1 month, 3 months, 6 months, 12 months
Secondary	Number of Participants With Repeat Treatments	Number of participants needing a repeat laser treatment during the study	18 months
Secondary	Number of Intraocular Pressure Lowering Medications	Number of drops and oral medications used by the patient compared to baseline	1 week, 1 month, 3 months, 6 months, 12 months, 18 months
Secondary	Corrected Distance Visual Acuity (CDVA)	Number of lines reduction or improvement from baseline on Snellen acuity chart at 6 meters	1 week, 1 month, 3 months, 6 months, 12 months, 18 months
Secondary	Cup-to-disc Ratio (CDR)	Progression of CDR compared to baseline, assessed by an ophthalmologist on dilated fundus examination	18 months
Secondary	Visual Field Index (VFI)	Determined by Humphrey automated perimetry Sita 24-2 visual field testing	18 months
Secondary	Mean Deviation (MD)	Determined by Humphrey automated perimetry Sita 24-2 visual field testing	18 months
Secondary	Pattern Standard Deviation (PSD)	Determined by Humphrey automated perimetry Sita 24-2 visual field testing	18 months
Secondary	Average Retinal Nerve Fiber Layer (RNFL) Thickness	In micrometer, determined by optical coherence tomography (OCT)	18 months
Secondary	Average Ganglion Cell Layer (GCL) Thickness	In micrometer, determined by optical coherence tomography (OCT)	18 months
Secondary	Cup-to-disc Ratio (CDR) Assessed by Optical Coherence Tomography (OCT)	Progression of vertical CDR compared to baseline, assessed by optical coherence tomography (OCT) parameters	18 months
Secondary	Pain Level During Laser Treatment	Using a verbal analog scale for pain level (none = no subjective feeling of pain, mild = pain easily tolerable, moderate = pain tolerable with difficulty, severe = pain intolerable)	1 day