Comparative study of Interventional Valve Enhancing Trabeculotomy and Kahook Dual Blade Goniotomy with Phacoemulsification in Open Angle Glaucoma

The study will be a Prospective  Randomized Control Trial study to assess the efficacy and safety of Interventional valve enhancing trabeculotomy (iVEnT)   versus Kahook Dual Blade (KDB)Goniotomy combined with phacoemulsification in open angle glaucoma (OAG)

Cataract and Glaucoma occur due to age-related ocular conditions They together cause the majority of blindness all over the world For glaucoma patients with visually significant cataract elective cataract surgery will be an opportunity to improve vision as well as to lower intraocular pressure (IOP) at the same time Cataract surgery by  Phacoemulsification lowers the IOP upto 1to 2mmHg but when combined with traditional glaucoma surgery it results in better IOP control Traditional Glaucoma Surgeries  are often associated with vision threatening complications like bleb leak, shallow anterior chamber , choroidal detachment and bleb-related infections like endophthalmitis.

Ab Interno trabeculotomy( a type of MIGS)   reduce the IOP in patients with glaucoma by incising or excising a part of  the Trabecular meshwork and inner wall of schlemms canal Since there is no bleb formation involved in these procedures vision-threatening complications are less.

Therefore the Aim  of this study is to compare the Efficacy and Safety of the two Ab Interno Procedures iVEnT and KDB Goniotomy with Phacoemulsification in patients with  Open Angle Glaucoma The study will be a Prospective Randomised Control Trial study to assess the efficacy and safety of Interventional valve enhancing trabeculotomy (iVEnT)    versus Kahook Dual Blade (KDB)Goniotomy combined with phacoemulsification in open angle glaucoma (OAG)

Primary objective:

To evaluate the IOP lowering and Safety Profile of  iVEnT combined with Phacoemulsification  compared to KDB Goniotomy combined with Phacoemulsification in Open Angle Glaucoma Patient.

 Secondary objective

To assess the number of Antiglaucoma Medications required postoperatively

To assess complications arising following the procedure.

To measure Schlemms Canal (Area, Width), Ciliary Muscle thickness at 1,2,3 mm from Scleral spur (CM1, CM2, CM3) using ASOCT CASIA 2 machine

  Inclusion criteria

Age  40 to 80 years

Diagnosis of OAG- Mild to moderate  POAG  Pseudo-exfoliative glaucoma Pigmentary glaucoma with Visually significant cataract BCVA less than equal to  6 by 12 on snellens chart

Vertical CD ratio less than equal to  0.8

Glaucomatous visual field defects with MD   less than equal to -12dB

Pre-op IOP more than equal to  21mmHg or IOP  more than equal to18 mm Hg with AGM

Open angle confirmed by gonioscopy using 4 mirror gonioscopy lens

Able and willing to attend scheduled follow up visits

Able and willing to provide informed consent

Non compliance to medication or not tolerating  AGM

Exclusion Criteria

Prior Glaucoma surgery or  laser.

Functionally severe field loss with a MD of more than -12 dB

Active ocular or  periocular inflammation.

Corneal abnormality that may interfere with visualization of angle  structures

Traumatic cataract

Retinal or optic nerve disorders that are not associated with existing  glaucoma condition

Elevated episcleral venous pressure

One eyed patients

Study area Glaucoma department of Aravind Eye Hospital, Tirunelveli Tamil Nadu.

 Study populationPatients coming to Glaucoma OP who are eligible will be included in the study after obtaining a written informed consent.

 Sample sizeA sample size of  140 eyes ( 70 eyes each group  )  will be required to assess the efficacy and safety of  iVEnT versus  KDB goniotomy with phacoemulsification in  OAG

 Study design Prospective, RCT

 Study duration 18 months  (6 months patient recruitment and  1 year follow up )

Follow up visits at 2 weeks 1 2 3 6  12 months