November 1, 2019 Conference


AM - Educating and Incorporating the New and Novel

Professional Practice Gaps:   Feedback from NEOS members and Program committee review identified:   Feedback from NEOS members and Program committee review identified potential practice gaps including knowledge on the latest diagnostic and surgical advances in glaucoma as well as new glaucoma medications and medications on the horizon

PROGRAM OBJECTIVES:   The content and format of this educational activity has been specifically designed to fill the practice gaps in the audience’s current potential scope of professional activities by:

  1. Increasing the awareness of and competence with some of the latest diagnostic and surgical advances in glaucoma
  2. Increasing the awareness of and competence with some of the newest glaucoma medications

INCORPORATING MIGS INTO PRACTICE
David Solá-Del Valle

New MIGS procedures continue entering the glaucoma world. MIGS can include a variety of procedures and can be divided into several categories: (1) those that enhance outflow through the trabecular meshwork, such as first-generation iStent, iStent inject, Kahook dual blade, iTrack, and Hydrus; (2) those that decrease aqueous humor production, such as endoscopic cyclophotocoagulation (ECP) and MicroPulse transcleral cyclophotocoagulation (MP CPC); and (3) those that shunt aqueous humor into the subconjunctival space, such as Xen Gel Stent. MIGS have been shown to be mostly safe and efficacious procedures, which can help lower IOP and decrease medication burden, even in patients with well-controlled glaucoma. The number of patients who benefit from MIGS continues to increase. As surgeons, we must decide which procedures we should/can incorporate into practice. The type of practice we have, whether it's a glaucoma-heavy practice with fellowship-trained glaucoma surgeons or mostly a cataract-surgery practice can help delineate which MIGS procedures we can consider adopting. Facility with intra-operative gonioscopy is key to add most MIGS procedures into a surgeon's armamentarium. A surgeon's patient population and patient selection are also crucial to successful MIGS incorporation into practice. Most MIGS best target mild-to-moderate open- angle glaucoma patients who require 1 or 2 medications for control. However, MIGS procedures can be combined to target patients who may require more medications for control. Some MIGS can even target refractory or advanced glaucoma patients. Emphasizing MIGS safety at the time of consent but also the possibility of more glaucoma surgery if MIGS fail to lower IOP is important to facilitate patients' acceptance of MIGS and avoid disappointment in the post-operative period and beyond.


MIGS: Lessons Learned
Peter T. Zacharia

The MIGS holy grail procedure is that which would improve upon the effectiveness of trabeculectomy, while reducing the risks, adverse effects, and recovery time, and simplifying and standardizing surgical and postoperative management.  Most glaucoma surgeons would agree that this has yet to be achieved.  Nevertheless some successes have been gained by expanding surgical options which we can tailor to specific glaucoma patient circumstances and characteristics including glaucoma mechanism, optic nerve damage severity and postoperative intraocular pressure goals, phakic status, prior ocular surgical history as it affects ocular anatomy and tissue status, age, health status, and anticoagulation status. 

MIGS procedures currently available and depending on what one chooses to include in this category of procedures reduce intraocular pressure by one of several different strategies.  One category of procedures enhances conventional aqueous outflow by either incision / excision,  ablation, or bypass stenting of trabecular meshwork, or by bolstering or augmenting Schlemm’s canal and outflow channel patency. A second category of procedures employs bypass devices to facilitate uveoscleral aqueous outflow through the suprachoroidal space. A third category of procedures uses fixed luminal diameter stents placed ab interno or ab externo to shunt fluid into the subconjunctival space with the goal of a more standardized and predictable approach with reduced anatomic disruption as compared to trabeculectomy.  A fourth category, cyclodestructive procedures, offer a less aggressive MIGS approach than older cyclodestruction techniques.  The glaucoma surgeon is tasked with selecting the appropriate MIGS procedure according to patient specific requirements as constrained by reimbursement and coverage realities as well as surgical skill set, but also with determining whether to choose a MIGS procedure or conventional trabeculectomy or glaucoma drainage device surgery.  Equally important are recognizing and managing complications and developing optimal postoperative care strategies which will enhance the success of MIGS procedures.


Use of Tube Shunts in the Surgical Management of Glaucoma
Steven Gedde

Tube shunt devices share a common design consisting of a silicone tube that is inserted into the eye through a scleral ?stula and drains aqueous humor to an end plate located in the equatorial region of the globe. Fibrous encapsulation of the end plate produces a reservoir into which aqueous humor pools.  The major resistance to aqueous outflow through the device occurs across the fibrous capsule around the end plate.  Therefore, the final IOP that is achieved after tube shunt surgery is determined by capsular thickness and surface area (i.e. thinner and larger surface-area capsules are associated with lower postoperative IOP).  Commercially available tube shunts differ in the size, shape, and material composition of the end plate.  Shunts are valved or nonvalved, depending on whether a ?ow restriction mechanism limits aqueous flow drainage if the IOP becomes too low.  A similar surgical implantation technique is used for all tube shunts.  Shunts are associated with many of the same intraoperative and postoperative complications as occurs with trabeculectomy.  Additionally, there are unique adverse events that may develop related to placement of a foreign material.  Medicare claims data and surveys of the American Glaucoma Society membership have demonstrated that tube shunts are being used with increasing frequency as an alternative to trabeculectomy.  Tube shunts have historically been reserved for eyes at high risk for filtration failure, but a growing clinical experience with these devices have prompted many surgeons to use them in less refractory cases.


Macular surveillance in glaucoma patients
Sarah Anis

Traditionally, most ophthalmologists consider Macular damage as end stage process in glaucomatous disease of optic nerve. And hence proceed with performing 10-2 VF only in advanced glaucoma disease when only Central Island is remaining and 24-2 VF is no longer worthwhile. However, there is enough evidence that macular damage can occur early in the glaucomatous process. Thereafter, it can be missed on 24-2 Visual fields in which the test points are separated by 6 degrees. The finer 2 degree grid is valuable not only in identifying accurately the damage but also to track progression1,3


In fact, macular damage picked up on 10-2 VF appears to occur as frequently as defects seen on 24-2 VF in patients with early glaucoma.  If relying only on 24-2 field defects to diagnose and treat glaucoma, clinicians will be delaying treatment and patients will be developing central visual deficit that can then detrimentally affect the vision-related QOL2. Adding 10-2 VF or Hybrid 24-2 VF may help in preventing missed glaucoma diagnoses and progression detection.

Next, Most physicians now perform OCT scan of the optic nerve but many do not obtain a scan of the macular region for patients with glaucoma or suspicion for glaucoma. Hence they can risk missing glaucoma damage4. Topographically comparing abnormal regions of OCT to abnormal regions of visual fields is helpful in eliminating above concern5.

 


Anterior Segment Imaging in Glaucoma
Sarwat Salim

Anterior segment imaging allows objective assessment of the anterior segment of the eye, particularly the anterior chamber angle. Both qualitative and quantitative analyses are possible and aid in detecting and managing closed-angle and open-angle mechanisms in various forms of glaucoma. This presentation will focus primarily on anterior segment optical coherence tomography and ultrasound biomicroscopy, with emphasis on principles of technology, commercially available devices, and clinical applications in glaucoma with potential advantages and disadvantages of each technology.


Lessons Learned from Glaucoma Clinical Trials
Steven Gedde

The randomized clinical trial is considered the most reliable form of scientific evidence and is the gold standard for evaluating the effectiveness of an intervention.  However, it is frequently difficult to translate the results of a trial into clinical practice. Several landmark glaucoma clinical trials have provided valuable information to guide patient care. A recent survey of the American Glaucoma Society membership suggested that the Ocular Hypertension Treatment Study (OHTS), Collaborative Normal Tension Glaucoma Study (CNTGS), Advanced Glaucoma Intervention Study (AGIS), and Tube Versus Trabeculectomy (TVT) Study are the glaucoma trials that have had the greatest impact on clinical practice. The OHTS evaluated the safety and efficacy of topical medications in preventing or delaying the onset of primary open-angle glaucoma in patients with ocular hypertension.  The CNTGS determined whether reducing IOP favorably influenced the course of normal-tension glaucoma.  The AGIS assessed the clinical course of two surgical treatment sequences starting with argon laser trabeculoplasty or trabeculectomy in patients with medically uncontrolled open-angle glaucoma.  The TVT Study compared the safety and efficacy of tube shunt implantation and trabeculectomy with mitomycin C in eyes with previous ocular surgery.  The methodology and major findings from each clinical trial will be reviewed, and recommendations will be made for applying these results to clinical practice.


New Medications and when do I use them?
James W. Hung

It has been over 20 years since the introduction of a new medication for the treatment of glaucoma.   With the introduction of Latanoprostene bunod and Netarsudil, there are finally new drugs with unique mechanisms of action to assist in intraocular pressure control.  We will review recent studies regarding efficacy and specific populations who may benefit from these new medications.


Glaucoma medications on the horizon
Milica Margeta

Intraocular pressure (IOP) is considered the only modifiable risk factor for glaucoma, and all current glaucoma treatment approaches focus on medical or surgical lowering of IOP. However, in many glaucoma patients, retinal ganglion cell (RGC) loss continues despite IOP lowering. Therefore, there is great interest in neuroprotection, which is defined as an intervention that targets the molecular mechanisms causing RGC death and hence enhances survival of RGCs independently of IOP control.

There have been many candidate molecules that have been tested for their neuroprotective effects in glaucoma, all with limited success in their translation to clinical use. For example, memantine, an NMDA glutamate receptor antagonist already used for treating Alzheimer’s disease, showed early promise in protecting against RGC loss in animal models of glaucoma. However, a subsequent phase 3 randomized, multicenter clinical trial showed that memantine treatment did not have a significant effect in preventing the progression of visual field loss in glaucoma patients. Many other molecules (neurotrophic factors, calcium channel blockers, antioxidants) showed early promise in animal models but were never tested in clinical trials in humans. We will discuss the reasons why it is difficult to translate findings from animal models into clinical use, and talk about newer methodologies in trial design and imaging that hold promise in translating the wealth of preclinical data into clinical practice. In addition, we will discuss a number of exciting new drug targets that have been recently identified with the advent of high-throughput genomic screens. These new approaches hold great promise for development of novel neuroproctive treatments for glaucoma. 


PM - Challenges in Cataract Surgery

Professional Practice Gaps:   Feedback from NEOS members and Program committee review identified Past comments have requested more information on optimizing the ocular surface.  Past comments have also suggested many advanced techniques would not be adopted by the routine cataract surgeon.  Although some surgeons may be reluctant to perform advanced techniques these discussions will help the surgeon identify the “landmines” and either be better prepared in the OR or to avoid these challenges by judicial referrals.

PROGRAM OBJECTIVES:   The content and format of this educational activity has been specifically
designed to fill the practice gaps in the audience’s current potential scope of professional activities by:

1.  Understanding the many challenges in cataract surgery in the less usual patient.
2.  Improving understanding of available IOLs and indications or contra-indications to their use.
3. Using an interactive video format to stimulate discussion and questions.


Challenges in Cataract Anesthesia
Teri Kleinberg

There are many approaches to anesthesia for cataract surgery including general, retro- and peri-bulbar block, and topical anesthesia with or without sedation. The selection of anesthetic for cataract surgery is based on many factors including surgeon familiarity, patient disposition, and regional (geographic) preferences. Barriers to topical anesthesia will be reviewed including patient anxiety, pain perception, and cooperation during surgery. Approaches to conscious sedation with and without intravenous access will be discussed.  The risks and benefits of the person responsible for administering and monitoring the anesthesia protocol will also be addressed.


Challenges in pediatric and special needs cataract surgery
Deborah K. VanderVeen

Young children with visually significant cataract(s) pose several unique challenges in management that are not typically encountered in the adult population.  The surgeon must be prepared to obtain intra-operative biometry, use special surgical techniques, consider refractive changes that inevitably occur in a growing eye when choosing an intraocular lens, and deal with increased inflammatory reaction and sometimes less than optimal cooperation for post-operative care.  This presentation will highlight techniques and tips that have been useful for safe surgical technique and successful post-operative management. 


Good Lenses Gone Bad; How to do an IOL exchange when all else fails
Steven Safran

The indications for IOL exchange include dhysphotopsias, refracve errors,  lens dislocations, IOL degenerations, damaged IOL optics or haptics, and UGH syndromes.   We will examine the problems that are commonly associated  with various types of intraocular lenses and then the anatomic issues that make lens exchange a challenge.   Surgical techniques to deal with specific presenting challenges will be presented and discussed at length.


Challenges in IOL Selection: Mixing IOLs to Optimize Patient Needs (Monofocal, Multifocal, Accommodative, EDOF, Toric vs FLACS with Relaxing Incisions)
Helen K. Wu

Modern cataract surgery allows patients not only to regain clearer vision, but also to do so with less spectacle dependence.  Currently available intraocular lenses (IOLs) include multifocal IOLs, extended depth of focus (EDOF) IOLs, accommodating IOLs, and monofocal IOLs.  Toric versions allow for correction of astigmatism with each type of IOL.   These lenses enable surgeons to offer their patients a refractive solution to optimize distance, intermediate and near visual acuities, although each IOL has specific benefits and limitations. An understanding of the available technology will allow surgeons to choose the most appropriate lens, or combination of lens technologies, that will provide the best vision for each patient. 

Multifocal IOLs allow the eye to see at multiple focal points in the distance and at near, either through refractive or diffractive technology.  These lenses allow the greatest independence from spectacles, but patients may experience halos and glare at night due to their optics. While trifocal IOLs provide improved intermediate vision compared to bifocal IOLs, they only recently have become available in the US and may be more expensive.  Thus, mixing and matching of bifocal IOLs with different near focal points is a popular method that affords an improved depth of binocular focus.  Extended depth of focus IOLs provide a continuum of foci that allows for excellent distance vision and intermediate vision, with improved contrast sensitivity relative to the bifocal lenses.  Near vision, however, is not as clear as with bifocal or trifocal IOLs. Surgeons may thus choose to implant an EDOF lens in one eye and a bifocal IOL in the fellow eye for improved near vision.  For patients with significant photic phenomena in the first eye after implantation of a multifocal or EDOF IOL, a monofocal IOL in the fellow eye may provide better night vision and preserved depth of focus.

Accommodating IOLs move slightly with flexion of the ciliary muscle within the eye, although their amplitude of accommodation is limited and patients typically still require correction for small print.  Because of their monofocal optics, night vision disturbances are minimized.  To improve near vision, some surgeons implant the non- dominant eye with either an accommodating IOL aiming for mini-monovision, or even occasionally with a multifocal IOL.

Currently, the most commonly implanted IOLs are monofocal lenses, whose advantages include reduced night vision disturbances and improved contrast sensitivity relative to multifocal IOLs.  For patients with corneal, optic nerve, or macular pathology, these lenses may provide the best quality of vision.  Depending on the patient’s vocational and lifestyle needs, monovision or mini-monovision monofocal IOL correction may be chosen to allow patients a greater binocular depth of focus. To correct astigmatism, toric IOLs may be implanted to achieve optimal refractive outcomes.  For those patients whose astigmatism is visually significant insufficient to qualify for a toric IOL, relaxing incisions are commonly used to correct regular astigmatism. 

In summary, as IOL designs have improved, cataract surgeons have an increasing array of choices to offer their patients better customized postoperative refractive solutions with improved quality of vision.  While there are many available options, the patient’s lifestyle and ocular exam, along with an understanding of the various IOL technologies, should help guide these decisions.   


Pars Plana Vitrectomy for the Anterior Segment Surgeon
Peter Chang

Objectives:

  1. To discuss the pros and cons of limbal-based vs pars plana vitrectomy when encountering posterior capsular rupture with vitreous loss and lens drop
  2. To illustrate the steps in conversion from phaco to pars plana vitrectomy, including sub-Tenon anesthetic administration, vitrectomy port establishment, microscope setup, basic techniques in endoillumination and core vitrectomy, and sclerostomy closure

Abstract:

When vitrectomy is required because of posterior capsular rupture with vitreous loss and dropped lens during phacoemulsification, there are circumstances when pars plana vitrectomy (PPV) may be more advantageous than the standard anterior approach. This talk will familiarize the anterior segment surgeon with the basic steps in converting from routine phacoemulsification to PPV, by means of video demonstration. The following steps will be shown:

  1. Anesthetic supplementation with Tenon cutdown and sub-Tenon anesthetic injection
  2. Establishment of the 3 pars plana ports
  3. Utilization of Resight® (Zeiss) or BIOM® (Oculus) to obtain good fundus viewing
  4. Endoillumination and core vitrectomy technique
  5. Sclerostomy closure


Cataract Surgery in Dogs. Differences and challenges
Stefano Pizzirani

A different species (dogs have a different anatomy and a higher predisposition to develop inflammatory reactions that is more similar to rabbits than humans[2]) including many different breeds with different predispositions to ocular diseases represents an intrinsic difference and offers diverse challenges. Lack of direct verbal interaction and lack of cooperation between patients and doctors limit the ability to rely on visual testing in a fine manner and to perform magnified examination. The mediation of owners is not always objective and reliable. Some of our patients present a challenge in terms of frequent rechecks, consistent treatment and basic hygiene. All this must be taken into consideration when selecting a patient, and it may be a source of concern in regard to owner compliance for treatments at home. Generally, our patients are admitted to the hospital for 2-3 nights, which may increase to 4-5 days in dogs experiencing challenging postsurgical hypertension. During hospitalization medications are administered by general veterinary technicians, which is another confounder factor in the final follow-up. Our patients need to be evaluated presurgically for underlying systemic conditions, which may or may be not known at the time of diagnosis. Ocular ultrasound and ERG are mandatory tests in every potential cataract surgery patient.   PRA, the equivalent of RP in humans, is common in purebred dogs and retinal degeneration has been reported to be present in 27% of dogs presented for cataract evaluation.[3] All our patients need to be fully anesthetized and neuromuscular blocking agents must be used for globe positioning, manipulation and to null extraocular muscle tone. The strongest and most developed extraocular muscle in dogs is the retractor bulbi, which is absent in humans. Dogs also have a third eyelid, which is a solid structure present in the ventro-medial orbit and limiting surgical exposure, to a point that in some patients, staying sutures are necessary to fully visualize the anterior chamber. This also makes a two-hand technique difficult in most of our patients and it’s the reason why the one-hand technique is still the most commonly used. The second hand assists in globe manipulation and exposure, due to the presence of the above mentioned third eyelid and to a physiologic enophthalmos present in many canine breeds. Most of our cataract patients are referred when the disease is already quite advanced and surgeries are commonly performed in late immature, mature or early hypermature stages. Cataract density varies and a specific detailed standardized classification of cataract surgical grades is lacking in veterinary field. The advanced cataract stages often represent a surgical challenge with anterior capsular fibrosis, nuclear hardness and posterior capsular plaques requiring specific attention. Equatorial capsular tears need to be ruled out in intumescent diabetic cataracts, which constitute about half of our cases. Mild to moderate intracapsular fibrin formation varies between different practices with some referring frustrating experiences and challenging solutions. Intracameral TPA is used to solve fibrin formation and can also be used as a default procedure at the end of the surgery. Most of canine eyes are implanted with a foldable hydrophilic or hydrophobic acrylic IOLs with UV protection, that have a standard power of 40-42D for all patients. [4, 5] The optic diameter varies depending on the manufacturing company, however it is usually about 6-7 mm in diameter, while the IOL size varies between 12 and 14 mm. Iris atrophy is a common, normal finding associated with aging in dogs and becomes a relevant figure to be observed in patients with a rounded pupillary edge, since it is an indicator of intraocular fibrosis. Glaucoma is very common in many breeds that are also predisposed to cataract and it is the most relevant concern for follow-ups. Post-surgical intraocular hypertension (2-4 hours after surgery) is common in 20-50% of the cases, [6, 7] and it is usually well managed pharmacologically in most of them. Glaucoma occurs in 10-30% of cases with its incidence increasing with longer follow-ups.[8-10] PCOs occur in 100% of patients after surgery, starting as early as 2 weeks postop. [11] Small and medium sized breeds seem more predisposed. The rate of axial opacification vs Sommering rings is however unknown. Pre-iridal fibrovascular membranes, lens fiber regrowth and lens epithelial membranes are also common complications reported in eyes enucleated after surgery, in which 76% had glaucoma.[12] 


Dysphotopsias: a better understanding
Steven Safran

Dysphotopsias are a common cause of patient dissatisfaction after cataract surgery and the case of these problems is often poorly understood.   This talk will attempt to take much of the mystery out of these conditions so that they can be evaluated more objectively and treated efficiently and effectively.  I will differentialte between the nature and causes of positive vs negaitve dysphotopsia and discuss the theories behind what causes these problems and how to treat them.


Challenges in Optimizing the Ocular Surface Prior to Cataract Surgery.  Influence on IOL Selection
Edward H. Jaccoma

Abstract

Ocular Surface Disease (OSD) can have a profound impact on pre-operative IOL calculations, postoperative cataract results and overall patient and surgeon satisfaction. Premium IOLs and refractive surgery outcomes raise the bar substantially. Advances in diagnostic and treatment technologies for OSD are discussed together with a relevant case presentation.