The Education Committee carefully selects presentations from the World Glaucoma Congress 2017 in Helsinki for your benefit. This edition Harsha Rao introduces several sessions on surgery: Surgery for angle-closure glaucoma, Surgery in pediatric glaucoma, Surgery in secondary and complicated glaucoma and Surgery in the developing world.
Surgery for angle-closure glaucoma
Surgical approaches to acute angle closure
Dr. Rojanapongpun discussed the fundamental concepts, approaches and procedures in the surgical management of acute angle closure. He said that angle closure is a surgical disease because surgical approaches are needed to address the angle closure mechanisms. He mentioned that the success of surgical approach in angle closure depends on the stage of angle closure (PACS, PAC or PACG) and the mechanism of angle closure (pupillary or non-pupillary block). He also spoke on the pros and cons of different laser and surgical procedures in the management of acute angle closure.
Pitfalls of trabeculectomy in angle closure
Dr Wong classified the pitfalls in trabeculectomy in angle closure into those pre-operative, intra-operative and post-operative. He discussed that the pre-operative pitfalls like misdiagnosis (primary versus secondary angle closure), wrong choice of surgery (trabeculectomy versus phaco versus combined) constitute the major bulk of it. He mentioned that the intra-operative pitfalls are mainly anaesthesia related and post-operative pitfalls are related to the higher risk of anterior chamber shallowing and malignant glaucoma in eyes with angle closure.
Key findings of the eagle study surgery for angle closure glaucoma
Dr. Azuara-Blanco discussed the key findings of the EAGLE study, a randomized controlled trial to compare the effectiveness and safety of early lens extraction and laser iridotomy in PAC and PACG eyes. He described the main results of the study in detail which showed a significantly greater improvement in quality of life, reduction of IOP and anti-glaucoma medications in the lens extraction group compared to laser iridotomy group. He also showed that lens extraction was cost effective and over long-term, cost saving compared to laser iridotomy. He also cautioned that the results should not be generalized to population not studied in the study.
Phaco with goniosynechiolysis: role and evidence
Dr Husain discussed the potential advantages and concerns of goniosynechiolysis (GSL). He also described the RCT conducted to compare the effect of phaco versus phaco + GSL in patients with PAC/ PACG with high IOP + ≥ 90 degrees of PAS and cataract. He mentioned that the RCT showed similar success rates (success defined as IOP < 21 mm Hg, >20% reduction in IOP between preop and 1-year postop time points and no anti-glaucoma medications) between the phaco and phaco + GSL groups. He also suggested that the success of phaco + GSL is likely to be better in PAC eyes compared to PACG eyes.
Surgery in pediatric glaucoma
Goniotomy: Tips and Tricks and how much angle is required for success
Dr Papadopoulos described in detail the procedure of goniotomy, highlighting the dos and don’ts of each step of the procedure. She also described the modifications of the procedure, factors that may play a role in the success of the procedure and discussed the possible mechanism of action by which the procedure works. She also discussed the advantages and disadvantages of the procedure.
Trabeculotomy: quadrant approach versus 360 degree surgery
Dr. Grehn discussed the challenges of trabeculotomy in pediatric glaucoma. He also discussed in detail the steps of conventional trabeculotomy and also elaborated on his way of doing the procedure which included a two level approach to Schlemm’s canal. He also spoke on the outcomes of conventional trabeculotomy. He later elaborated the procedure of 360 degree trabeculotomy and compared the success of this procedure against that of conventional trabeculotomy.
Trabeculectomy in children
Dr Khaw elaborated each step of trabeculectomy in detail and highlighted the precautions required in each step to prevent the possible early and late complications. He discussed the Moorfields safer surgery system and how this technique has reduced the incidence of post-trabeculectomy complications in children.
Tube surgery: Does size or valved matter?
Dr Brandt described the indications of tube in pediatric glaucoma and also reviewed the literature on the outcomes of pediatric tube surgery. He also reviewed the literature on the use of anti-fibrotic agents in pediatric tube surgeries. He then summarized the different valved and non-valved drainage devices, discussing the advantages and disadvantages of each of them. Finally, he went over the steps of the pediatric tube surgery in detail highlighting the precautions required in each step to avoid complications.
Surgery in secondary and complicated glaucoma
Rodolfo Perez Grossman
Dr. Grossman enumerated the causes and mechanisms of high IOP after various retinal surgeries. He then discussed the role of GDD in the management of secondary glaucoma in these eyes.
Post DSAEK or penetrating keratectomy
Dr. Wong discussed the various mechanisms of glaucoma (high IOP) in eyes with penetrating keratoplasty and DSAEK. She also discussed the effect of DSAEK in eyes with pre-existing glaucoma and in eyes with pre-existing glaucoma filtering surgeries like trabeculectomy and GDD. She also discussed the management of high IOP in DSAEK and PK eyes, and the outcomes of trabeculectomy in these eyes.
Dr. Coote described the big problems seen in small eyes (extreme hyperopia or nanophthalmos). He discussed the challenges of cataract surgery in nanophthalmic eyes and highlighted these difficulties by demonstrating a few surgical videos.
Kyung Rim Sung
Dr Sung discussed the possible complications of filtering surgeries in high myopic eyes and the reasons for the same. She also described tips to reduce the incidence of the surgical complications like hypotony in high myopic glaucoma eyes.
Nagib Du Toit
Dr Toit enumerated the challenges in the management of glaucoma in African countries; late presentation, need for early surgery, increased scarring, poor compliance, need for multiple procedures to control IOP and late MMC-related bleb leaks. He also discussed in detail measures that could be employed to tackle these challenges.
Dr. Sihota spoke on the outcomes of trabeculectomy in Indian patients. She discussed studies that evaluated the long-term success of trabeculectomy in Indian eyes with glaucoma. She also highlighted the precautions that are required to avoid complications of trabeculectomy and the methods to effectively manage these complications when they arise. She also discussed that the definition of success in trabeculectomy surgery should be redefined as IOP levels of <15 mm Hg, absence of hypotony and absence of thin walled blebs.
Dr. Cook discussed the prevalence of glaucoma in African continent and the need to estimate “glaucoma surgery rate” (similar to “cataract surgery rate”) in various geographical regions. He discussed the role of beta radiation as an adjunctive agent in preventing bleb scarring in trabeculectomy surgeries. He also enumerated the results of a study comparing the outcomes of trabeculectomy with adjunctive beta radiation versus MMC. He also discussed that a possible reason for low “glaucoma surgery rate” in the region was the low confidence and competence in eye surgeons for performing glaucoma surgeries.
Dr Congdon suggested strategies to screen for glaucoma in different geographic areas of China (urban versus rural) and different clinical settings (clinic versus population). He discussed the results of a study which evaluated barriers to surgical care in patients undergoing trabeculectomy in rural county hospitals in China and then enumerated measures to tackle these challenges.