
This article was reviewed by J. Fernando Arevalo, MD

The new generation of genetic mapping provides more information about retinitis pigmentosa (RP), which should help identify new treatment approaches. 

A recent study showed that patients with an identified pathogenic variant had lower visual acuity (VA) levels that were associated with the length of the inner segment/outer segment (IS/OS) junction.



Retinal implant improves quality of life in patients with RP

Investigators conducted a retrospective, observational case study to determine the ocular characteristics and genes affected in patients with a clinical diagnosis of RP.

Twenty-one patients who had been diagnosed with RP underwent a comprehensive ophthalmologic examination that included spectral-domain optical coherence tomography to measure the central retinal thickness (CRT) and the length of the foveal IS/OS junction. 

Blood samples were analyzed for sequencing and deletion/duplication testing for 248 genes, according to Agustin Loria, MD, a retina fellow at Valley Retina Institute in McAllen, Texas.



Overall, the mean visual acuity was 1.21 logarithm of the minimum angle of resolution (logMAR), mean IOP 14.9 mm Hg, mean CRT 232 μ, and mean IS/OS junction length 1526 μ.

The investigators identified a pathogenic variant in 14 of the 21 patients. The most common of these were variants in the following genes: the 

Harnessing regeneration of retinal tissues: An option almost within reach

The patients were divided into groups A and B based on the classification of the genetic variant, that is, group A, those with a pathogenic variant, and group B with an uncertain significance variant, he explained.

In group A, the mean VA was 1.47 logMAR, IOP 13 mm Hg, CRT 226.1 μ, and IS/OS junction length 683.86 μ. In group B, the respective values were 1.18 logMAR, 15 mm Hg, 236.46 μ, and 1577.63 μ.

“Even though not all the patients had pathogenic variants, all of them demonstrated typical phenotypic and clinical findings associated with retinitis pigmentosa,” Loria concluded. “We found that patients with pathogenic variants had lower VA that was correlated with the length of the IS/OS junction.”

Future studies with more patients are needed to confirm these results, Loria noted. 



Loria has no financial interest in this subject matter.

Articles

Patients with pathogenic variants experience lower VA tied to length of IS/OS junction.

Study: Some RP abnormalities are linked with lower visual acuity


This article was reviewed by Delaney Curran

 (DR) Teleretinal screenings are less costly than office visits and help preserve vision. The screening can be performed in primary-care practices and may improve patient adherence to annual examinations, which historically is on the low side.

While effective in preserving vision, annual screening has the potential to increase medical costs.

Identifying biomarkers to predict diabetic retinopathy progression


This expense is magnified because the cost of treating DR has increased significantly due to the high cost of intravitreal anti-vascular endothelial growth factor anti-VEGF, which accounted for 22% of the Medicare Part B total drug spending in 2018, according to Delaney Curran, a medical student at Larner College of Medicine at the University of Vermont, Burlington. “This highlights the importance of controlling all costs of DR management,” Curran said.

In a study, Curran and colleagues wanted to determine how teleretinal screening would work in an accountable-care organization in which health providers are incentivized to follow models that improve the health of the population. She said this can be a better care experience for patients, and have lower costs.

The research study focused on three objectives: (1) determining the cost of teleretinal screening compared with an annual examination taking place in an ophthalmology office; (2) determining the direct medical costs that included those of anti-VEGF therapy for 1 year; and (3) the visual impairment outcomes at 1 year, Curran pointed out.



ASRS 2020: New imaging modalities offering bold, noninvasive, real-time monitoring of retinal diseases

According to Curran, the investigators used software (TreeAge Pro) to compare the cost-effectiveness of teleretinal screening with that of in-person screening. This decision-tree analysis attempts to model real life through probability analysis. 

In this case, the analysis would predict the endpoints of undetected retinopathy and the diagnosed and treated DR for both teleretinal screening and in-person examinations. 

The outcomes included the average incremental costs and disability weight and probability that teleretinal screening is cost-saving and more effective.

The results showed that the most likely pathway indicated that 36% of patients in each intervention type will not attend their screening and will not have DR or macular edema, Curran said.

FA implant outperforms anti-VEGF in DR patients lost-to-follow-up

The second most likely pathway indicated that 30% will undergo teleretinal screening and not have DR and 34% will undergo an in-person examination and will not have DR or macular edema.

The average annual costs per patient for teleretinal screening and in-person screening are, respectively, $230 and $292. 

On average, this amounts to a saving of $62 compared with in-person screening and a cost savings 98.4% of the time. 

Teleretinal screening resulted in a lower disability weight 55.9% of the time. The patients who underwent teleretinal screening also had a lower average cost per person when the cost of screening was less than $160, Curran said.

Based on the results of the study, teleretinal screening is a cost-saving tool and less expensive than screening during an office visit. This is likely because teleretinal screening eliminates the need for more expensive in-person examination for patients who do not have DR, who comprise the majority of the population. 


Imaging retinal pathologies can be challenging with current technologies



Anti-VEGF treatment is an expensive component of the treatment costs; however, this cost will be high regardless of the screening method. Teleretinal screening also preserves vision as effectively as in-person examinations, because of only small differences in specificity and sensitivity.

The investigators will continue with their research to determine the relative costs and vision outcomes when both interventions are available.


Curran has no financial interest in this subject matter

Process eliminates need for expensive in-person examination of patients without DR.


Teleretinal screening: Effective, less costly option for DR

This article was reviewed by Neeraj S. Chawla, BS

 power calculation formulas that take into account total corneal power measurements and the differential effect of corneal laser refractive surgery on anterior and posterior corneal curvature aim to improve refractive accuracy in eyes with a history of LASI or PRK.

However, findings from a retrospective clinical cohort study of 170 postmyopic LASIK eyes showed that, when comparing IOL power predictive accuracy, the Pentacam Scheimpflug camera-based Potvin-Hill and spectral-domain 

–based True-K formulas did not necessarily outperform other select formulas available on the American Society of Cataract and Refractive Surgery (ASCRS) IOL calculator.


Getting it right: There is no magic bullet for IOL calculations

The research was conducted by Neeraj S. Chawla, BS, a medical student at the University of Illinois at Chicago, and Navaneet S. Borisuth, MD, PhD, who is in private practice at Virdi Eye Clinic, with 3 locations in Illinois and Iowa. Chawla presented the findings at the 2020 ASCRS virtual annual meeting.

“Potential limitations of our study included a lack of complete historical LASIK data, as well as sample size,” he said. “Therefore, we believe future studies should continue to explore the Scheimpflug camera-based and OCT-based formulas using larger patient populations [and] tighter experimental conditions, as well as various subgroup analyses.”

Borisuth noted that further investigation may determine the degree and specific conditions in which these imaging-based formulas will improve patient outcomes from cataract surgery.

“The Potvin-Hill and OCT True-K formulas confer a theoretical advantage based on their advanced imaging techniques that incorporate total corneal power,” he said. “For example, the Pentacam rotating Scheimpflug camera may be specifically useful when planning for astigmatic correction in postmyopic LASIK eyes.”

Patients included in the study were operated on by Borisuth, with consideration of post-myopic LASIK eyes receiving monofocal, toric, or extended-depth of focus IOL implants. Eyes with concurrent corneal or retinal pathology were excluded from the study. 



Aspheric, aberration-free IOL leverages technology for performance



Postoperatively, 81.6% and 91.1% of eyes fell within ± 0.5 D and ± 1.0 D of target predicted refraction, respectively, therefore indicating “generally favorable” surgical outcomes.

IOL power formula predictive accuracy was determined using postoperative refractive data to back-calculate optimum IOL powers and absolute prediction errors.

The formulas analyzed included the Scheimpflug camera-based Potvin-Hill and spectral-domain OCT-based True-K, as well as other conventionally available formulas of the ASCRS IOL calculator. These included the Barrett True-K, Barrett True-K no-history, Masket, Modified Masket, Shammas, Haigis-L, and ASCRS Average formulas.

Mean absolute prediction error ranged from a low of 0.40 ± 0.33 D for the Barrett True-K formula to a high of 0.67 ± 0.51 D for the Shammas formula. 

Statistical analyses revealed that the Barrett True-K, ASCRS Average, and Masket formulas were significantly more accurate than the OCT True-K and Shammas formulas only. No other statistically significant differences were derived.



Haigis-TK power calculation formula provides best error prediction after LASIK

Additional subanalyses assessed directional relationships between predictive error of the imaging-based formulas with axial length and optimum IOL power. 

These analyses found that the accuracy of the Potvin-Hill formula improved with increasing axial length and decreasing optimum IOL power, whereas the OCT True-K formula was most accurate for midrange axial length and midrange optimum IOL power.

“The Potvin-Hill formula typically underpredicted optimum IOL power, [whereas] the OCT-based formula did not show directionality,” Chawla said. 



Chawla has no financial disclosures related to this content. He recently started his thirdyear medical rotations at the University of Illinois in Chicago. He graduated from Emory University in 2018 with a degree in neuroscience and behavioral biology. 


Borisuth has no financial disclosures related to this content. He is a fellow of the American Academy of Ophthalmology, the American Glaucoma Society, and the Society of Heed Fellows.

Study finds imaging-based formulas are less accurate in post-myopic LASIK eyes.

Investigators challenge IOL power calculations

Sir Harold Ridley implanted the first IOL on February 8, 1950. Charlie Kelman’s US Patent for phacoemulsification was filed July 25, 1967.

Following the introduction of these foundational elements of modern 

, myriad incremental innovations has brought about what is surely the fastest, safest and most effective surgical procedure in the world today. 

These innovations include reducing the size and therefore the morbidity related to incisions, increasing the efficiency of lens extraction by optimizing the energy required to break up and evacuate the lens and improving the accuracy of 

 power calculations to refine postoperative refractive outcomes.




Small-aperture single-piece IOL could fill unmet need in patients

The development of adjunctive tools and tricks to alleviate the negative impact of pre-existing risk factors such as a small pupil or a weakened zonule has improved the safety of surgery, while the introduction of the femtosecond laser has created a new opportunity for innovation and precision in the treatment of astigmatism. All of these advances have combined to make a really big “wow” for our patients.

Clinical research has also produced important advances in our knowledge of cataract surgery. One of the most significant findings of recent studies of minimally invasive glaucoma surgery is confirmation of the substantial reduction of intraocular pressure in patients with mild to moderate glaucoma from cataract surgery alone. 

Investigational device exemption randomized clinical trials of both the CyPass and the Hydrus demonstrated a remarkable concordance in terms of the proportions of subject eyes in the control groups with unmedicated mean diurnal IOP reductions greater than or equal to 20% from baseline (57.8% compared with 58.0%) and the reductions in the control groups in unmedicated mean diurnal IOP from baseline (both -5.3 mmHg). 



Study results show that surgical system decreases IOP in patients with POAG


These clinically significant reductions in IOP in glaucoma patients having cataract surgery alone has now been demonstrated by randomized, controlled clinical trials which provide the highest standard of evidence for this phenomenon.

Nevertheless, challenges remain to provoke the imagination of scientists and entrepreneurs as global demographics predict an increasing demand for cataract surgery. 

For example, cystoid macular edema, or Irvine-Gass Syndrome, remains the most common complication associated with routine cataract surgery and can occur in patients with or without risk factors, such as diabetes or pre-existing macular disease. 

While topical anti-inflammatory agents are considered prophylactic in the perioperative period, the use of intravitreal anti-VEGF agents as treatment has garnered support. This unpredictable and potentially sight-threatening complication deserves attention. 

Another example of an unpredictable complication, capsule contraction syndrome, is related to fibrous metaplasia of lens epithelial cells similar to the pathogenesis of posterior capsular opacification and usually occurs within the first 3 months following surgery. 



Pre-operative IOP hints after cataract surgery



Changes in refraction may occur due to axial displacement or tilting of the 

due to the capsular contraction. 

Capsule contraction syndrome “has occurred in eyes with and without risk factors after the implantation of every IOL type (PMMA, silicone and acrylic).” 

Identified risk factors include small capsulorhexis diameter, postoperative inflammation, pseudoexfoliation syndrome, uveitis, retinitis pigmentosa, history of retinal surgery, myotonic dystrophy and diabetes.

Treatment of capsular contraction syndrome has relied primarily on Nd:YAG laser relaxing anterior capsulotomies to eliminate constriction. Radial capsulotomies “can significantly enlarge the anterior capsule opening” but “the IOL can remain decentered and folded within the capsular bag, especially in case of shrinkage or thick fibrous anterior membrane. ”Femtosecond laser capsulotomies have advantages in terms of precision, and, despite difficulty cutting thickened capsular tissue, are “easier and safer than previous techniques. ”



Minimize inflammation after cataract surgery

On a personal note, I remember the day during my junior year of residency when it suddenly dawned on me that my father had been left aphakic after his cataract surgery with Robert Sinskey, MD, the inventor of the Sinskey hook. I can recall seeing my father put in his contact using a pair of specially made glasses with only one lens. 

At that time, “the implant” was still very controversial, as Ralph Nader had testified against its use before the FDA. It was actually testimony from Robert Young, who played “America’s doctor” Marcus Welby on television, that supported the benefits of the 

. 

One patient, actor Robert Young, testified that at age 72 he is able “to see and work again thanks to the miraculous medical breakthrough” of a pair of these artificial lenses.

 development is that innovation is not for the weak of heart. Early phaco, just as much as early IOLs, did damage many eyes. Nevertheless, perseverance had great rewards, and it will no doubt continue to do so as we invent the next generation of cataract surgery innovations. 

, did damage many eyes. Nevertheless, perseverance had great rewards.

--- 


Packer is a consultant to Bausch + Lomb.

Innovations have made procedure quick, safe, effective.

The history of progress and innovation in cataract surgery


This article was reviewed by Kyle T. Packer, MD

Posterior chamber implantation of implantablecollamer lenses (ICLs) provided robust, stable results in a young population during an 11-year period. 

Most of the data are significant out to 8 years of follow-up, according to Kyle T. Packer, MD, who is with the US Army and practicing in Hanover, New Hampshire.

The results were garnered from a retrospective longitudinal study of 3004 eyes implanted with the ICLs at a US military treatment facility from 2008 to 2019. 



Robotics: Allowing surgeons to perform the seemingly impossible



All patients underwent standard refractive procedures and measurements preoperatively and postoperatively.

The median patient age was 25 years; 67% of patients were men. The median baseline spherical equivalent (SE) was –5.87 D.

Packer reported that the mean SE turned slightly myopic over the first 7 years postoperatively. The mean uncorrected visual acuity (UCVA) exceeded 20/25 and the mean best-corrected visual acuity (BCVA) exceeded 20/20 in all patients out to postoperative year 7.

ICLs were implanted in patients because of the presence of abnormal topography or moderate or high levels of myopia.

A comparison of the preoperative and postoperative BCVA showed that about 40% of patients had a gain of a minimum of 1 line of BCVA during the first year after implantation, indicating the safety of the ICLs.



Physicians' treatment decisions are reinforced with good data

The endothelial cell count decreased over time postoperatively compared with the baseline, which resulted in a significant overall decrease of 14.4% from baseline to the 5-year time point.

Patients had a significant increase in the IOP to the 1-year time point, and decreased from years 2 through 8.

The vault was estimated as a percentage of the corneal thickness. Low vaults were defined as less than 50% of the corneal thickness, ideal vaults from 51% to 200%, and high vaults over 200%. In this patient population, most vaults were considered ideal.

“The trend over time was a decrease in the vault size, especially after year 7, with no vault size over 157% of the corneal thickness,” Packer said.

Adverse events occurred in 1.2% during the 11-year follow-up, which included the formation of visually relevant cataracts, glaucoma, retinal detachment, and traumatic incision opening. The ICLs were removed in 4.5% of eyes in most cases because of low vaults.


Persistent retinal detachment connected to retinoblastoma


Physicians often use lenses due to abnormal corneal topography or high myopiaThe main takeaways from this study were the following: 

(1) ICLs were implanted because of abnormal corneal topography or high myopia; 
(2) refractive results associated with the ICLs were robust and stable during the long-term follow-up; 
(3) vault size decreased over time, which suggested an increased risk of cataract formation after 7 years; 
(4) a decrease in the mean endothelial cell count of about 14.4% at the fifth postoperative year suggested that another study is needed to assess the long-term clinical significance.

Physicians often use lenses due to abnormal corneal topography or high myopia

ICLs: Investigators finding robust and stable results over long term

Forty-five years have brought major changes to the field of 

. In 1975, retina fellowship training had existed for only about 26 years and there was only one subspecialty society, The Retina Society.

At that time, much of science and medicine was based on observation and training focused on surgical areas.

Over the ensuing four decades, there have been major advances in our understanding in science, technology, optics and medicine, as well as in surgery, which have tremendously changed the ways we diagnose and treat patients with retinal diseases.


At that time, much of science and medicine was based on observation and training focused on surgical areas. 

Over the ensuing four decades, there have been major advances in our understanding in science, technology, optics and medicine, as well as in surgery, which have tremendously changed the ways we diagnose and treat patients with retinal diseases.

With an increased understanding of diseases and new treatments, areas of study within retina have grown and are now recognized as subspecialties in their own right, for example, pediatric retina, uveitis, and inherited retinal diseases. 

When considered among other medical or surgical specialties, ophthalmology/retina has accomplished firsts: development of optical coherence tomography, human gene therapy to treat an inherited disease, first FDA-approved method to use artificial intelligence to characterize retinal disease, as a few examples.

The evolution of genetics and molecular biology have led to recognition of gene associations with human diseases and the ability to study gene variants, as well as the signaling pathways involved, in the pathophysiology of a given disease. 

Tools including genetic knockout, inducible conditional and transgenic models have enabled scientists, clinicians, and clinician scientists to pursue study of molecules in specific cell types and how these influence human disease.



Experimental methods led to the development of treatments: anti-angiogenic agents in retinovascular and choroidal neovascular diseases, immunosuppressive agents in uveitis, and gene therapy to treat some inherited retinal diseases as well as to understand complex pathophysiology of chronic diseases that potentially leads to future treatments. 

Now, blindness from a form of retinitis pigmentosa can be treated by replacing a mutant RPE65 allele with gene therapy. 

Clinical trials have evolved to test hypotheses developed from experimental studies, and then following interpretation of outcomes, to present new hypotheses to be studied experimentally (bench to bedside to bench model).

The development of optical coherence tomography has bridged pathology, once appreciated only after removal of an eye, to real-time by associating retinal pathology with visual acuity and human symptoms over time and following intervention. 

Advances in biomedical engineering have led to methods to restore vision through computer chips and to test cell and biomedical interfaces for future treatments.



AAO live: Autologous retinal transplant for larger macular holes gaining traction

It is impossible to list all the advances, but I will highlight a few. Diabetic retinopathy has evolved from preventing blindness to potentially reversing severity and improving vision. 

In 1981, success was reduction in 2-year incidence of blindness by 60% with panretinal photocoagulation. Over the next decades, laser maintained vision loss in DME

; then, anti-VEGF agents or steroids improved visual acuity and reversed disease severity in some patients. 

An FDA-approved camera using artificial intelligence to characterize DR severity is hoped to characterize features of the 60% of patients with DME who do not respond to current treatment.

In age-related macular degeneration (AMD), laser to choroidal neovascularization slowed progression to legal blindness, with success as maintaining visual acuity. Currently, anti-VEGF agents can improve vision in patients with neovascular AMD.

 

Clinical studies are identifying the burden of vision loss in atrophic AMD and clinical trials are testing new therapies for it.

Increasing recognition that surgical management of pediatric retinal diseases differs from other fields of ophthalmology has led to improved outcomes. 

In ROP, classification of early disease in the 1980s allowed testing of a destructive treatment of the peripheral avascular retina to reduce the hypoxic drive of abnormal angiogenesis first with cryotherapy and then laser.



Probe of IRIS registry: Anti-VEGF injections key treatment for PDR

Now, from experimental studies, anti-VEGF agents are used to regulate the VEGF signaling pathway and regress intravitreal growth of blood vessels and, for the first time, facilitate vascularization of the peripheral avascular retina. 

New studies are evolving to safely regulate angiogenesis in these fragile, developing premature infants so as not to adversely affect other organs, including the brain.

Surgical improvements include the development of small gauge vitrectomy and imaging. Microscopic surgery required flat contact lenses that afforded only a limited view of the posterior retina. 

Now wide-angle viewing systems permit a larger field of view; heads-up displays magnify images with stereopsis and better ergonomics for the surgeon; and intraoperative OCT allows visualization of vitreoretinal and subretinal layers, critical for surgery and gene therapy.

Therapies have evolved not only to be globe salvaging in certain tumors, but to preserve vision through chemotherapy, and increase understanding of molecular mechanisms involved to improve diagnostic prediction of tumor severity and recurrence.

When we look back at where we were, we realize that it has been a productive and amazing 45 years! The changes we see now seem to be increasing exponentially each decade. It is hard to predict what the future will hold from where we are now.



Mary Elizabeth Hartnett, MD, FACS, FARVO


Hartnett is a professor of ophthalmology at the John A. Moran Eye Center at the University of Utah in Salt Lake City.

Advances in treatment and surgical techniques have transformed patient care.  


Exploring four decades of change in retina

 surgery, dual-blade goniotomy and direct viscodilation of the collector channels with cataract surgery, effectively rejuvenates the outflow system that results in a dramatic increase in the number of eyes that do not require anti-glaucoma medications.

“The trabecular meshwork and collector channels are the conventional outflow pathway that is responsible for at least 50% of outflow resistance,” said Linda Burk, MD, clinical professor of ophthalmology at the University of Texas Southwestern Medical School in Dallas. “The question is: Can this pathway be rejuvenated?”




During consideration of an improved procedure, she described that the Kahook Dual Blade (New World Medical) can cut parallel incisions, minimize collateral damage, and does not leave trabecular meshwork leaflets in its wake that can lead to fibrosis. 

Burk noted that her previous trabecular meshwork specimens were characterized by loss of cells and collagen deposits.

Burk’s search for the improved procedure led to the combination procedure that included removal of the trabecular meshwork with use of the Kahook Dual Blade, which resulted in direct viscodilation of the collector channels and decreased hyphemas.


In this innovative technique, Burk uses the dual blade to “glide along” Schlemm’s canal to remove the trabecular meshwork. 

She adjusts the lens to open more of the canal. Generally, the trabecular meshwork comes out on the dual blade. Healon is injected to define the canal by holding the cannula snuggly against the back wall as more Healon is injected. 

At this point, Schlemm’s canal is now a “clean gutter.” The anterior chamber Healon and any residual debris then is removed. 



Traditional glaucoma surgery in the era of MIGS procedure


She explained that lowering the intraocular pressure (IOP) allows blood to backflow into the anterior chamber and demonstrate that Schlemm’s canal is open. 

Filling the anterior chamber with balanced saline solution shows the episcleral fluid wave.

Burk reported the 18-months results of this procedure in 120 eyes 1 year after the procedure. Half of the patients had moderate to severe

 surgery. 

The mean baseline IOP of 18.8 mm Hg decreased to 16.2 mm Hg at 18 months; 85% of patients achieved this result without the use of medications.

The results showed that 94% had an IOP of 21 mm Hg or lower, and 42% had 15 mm Hg or lower. The reduction in the overall use of medications was significant, with a saving of $84,000 in the first year, according to Burk.

IOP homeostasis in glaucoma: Looking below the surface

 used no medications, that is, 48% at 3 months and 45% at 12 months,” she said, adding that in the presence of advanced glaucoma the outflow system was thought to be irreversibly damaged. “The outflow system can be rejuvenated in advanced glaucoma.”

An advantage of the procedure under discussion is that it is repeatable, which was done in 4 eyes at 15 months after the initial procedure and then again 8 months later. Three of the patients did not require medications at 2 years.


Burk concluded that combined goniotomy and viscodilation allows access to diseased tissue by removing the trabecular meshwork and access to and viscodilation of multiple connector channels.

and has a low complication rate and fast recovery,” she said. “Cleaning the gutter and power washing the downspouts is a safe and effective way to rejuvenate the conventional outflow pathway, reduce the financial burden, and improve compliance. It’s time to rejuvenate the outflow system.” 



e: aphillips@dallaseyeandear.com
Burk has no financial interest in this subject matter.

Goniotomy-viscodilation cataract surgery controls IOP without medications.

Rejuvenation of outflow system: The time has come for procedure


When it comes to understanding who is affected by 

, 1975 was a time of great confusion for those interested in the disease. The confusion persists.

Six years earlier, Mansour F. Armaly, MD, showed that without treatment few ocular hypertensive patients developed visual field loss over 5 years. 

Prior to the study, widespread agreement that glaucoma was present when the IOP was over 21 mm Hg led ophthalmologists to recommend treatment whenever IOP was above this number. 


Glaucoma devices: Now and in the future​ 

​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 
While prevalence surveys have dispelled the myth of 21 mm Hg, many ophthalmologists continue to believe that using an absolute level of IOP in making a glaucoma diagnosis is in the best interest of their patients. 

The distinction between open angle and normal tension glaucoma as two different disease entities remains controversial.



The majority of the world’s people with 

continue to be undiagnosed and untreated. In 1975, “correct” diagnosis and treatment were clear, and “easy,” even though often wrong. 

Today, diagnosis and treatment are less clear, with limited understanding about the variability of rates of progressive damage. 

Some tests considered essential in the past, such as tonography, are no longer used, while others, such as central corneal thickness or the retinal nerve fiber layer are used with great devotion.



Angle-closure glaucoma caused by relative pupillary block was a leading cause of irreversible blindness in 1975. The development of laser iridotomy offered the possible elimination of pupillary block 

. 

However, angle-closure is still a major cause of worldwide blindness. Recent studies are clarifying who needs treatment and what types of treatment are preferable. 

Modern cataract surgery has emerged as a useful early intervention for patients with angle closure as well as for those with open angles and glaucomatous nerve damage.

The search for a workable definition of glaucomatous disease has intensified. Many acknowledge that the etiology of this optic neuropathy varies substantially between individuals and populations. 

The fixation on determining whether someone has glaucoma based upon cross-sectional information at a single time point has been questioned by some who believe there is little benefit, and perhaps harm, in labelling individuals as having or not having 

Clinical trials have shown that a large proportion of glaucoma patients randomly assigned to no treatment show no progression for many years.

Deciding on the actual need for treatment is still difficult, at least partially because of the lack of data that relates early changes to the development of actual disability caused by glaucomatous vision loss.


Funding new technologies for glaucoma treatment​ 



Fear of going blind is so great that both doctors and patients alike tend to opt for the apparent safety they associate with treatment, even in circumstances when treatment is not necessary to preserve quality of life. 

On the other hand, fear of problems caused by incisional surgery is sometimes so great that doctors and patients tend to defer surgery that is actually necessary to prevent the development of troublesome loss of vision in those with severe and progressive disease. Future studies need to focus on the long term consequences of 

In diagnostics, during the past 45 years, we have seen effort, thought and finances devoted to both functional and structural assessment of people with or suspected of having 

. Transition from manual to automated perimetry has been a true advance.

The decreased utilization of fundus photographs has likely had a negative impact on glaucoma care. Small changes in optic nerve and retinal nerve fiber layer can be better measured with a host of novel imaging technologies, but the significance of such change is often not clear. 

A diagnosis of 

is best made longitudinally; measures that change over time without validated reference parameters for comparison may not represent progress.

The efforts to show structure-function correlation with regard to optic nerve pathology have been limited by large variability using present day tools, thus limiting the use of structural change as a surrogate for present or future vision loss in individuals.



Traditional glaucoma surgery in the era of MIGS procedures

Glaucoma therapeutics has seen two great milestones in pharmacologic care: The introduction of topical beta-blockers in 1978 and prostaglandin analogs in 1996. Both, along with topical carbonic anhydrase inhibitors and alpha adrenergic agonists introduced in the 1990s, are now available as generic medications.

Nevertheless, their cost is prohibitively high for many, particularly in developing countries. Noncompliance with medications remains a large problem; missing appointments is also a great concern.

Laser trabeculoplasty, first introduced about 45 years ago, was initially slow to be utilized. 

Frequency of use increased in the 1990s with the development of more selective approaches; clinical trials indicate initiating treatment with laser is a good option for many patients with open- angle glaucoma. 

Minimally invasive surgical approaches, focused most often on increasing outflow through Schlemm’s Canal, and often combined with cataract surgery, have allowed surgical 

 to enter comprehensive ophthalmology practice. 

While these procedures have been shown to decrease the short-term postoperative dependence on IOP-lowering medications amongst patients with mild to moderate glaucomatous disease, the long term benefit that they provide requires further study.


Various implantable devices designed to give trabeculectomy-like results have shown mixed results. Cyclodestructive procedures have been refined and are viable alternatives in some cases. 

Increasing use of drainage device implantation in eyes having had prior incisional surgery has been supported by clinical trials, but trabeculectomy remains the most efficacious first procedure for patients otherwise destined for severe vision loss from glaucomatous disease. Recent evidence shows improved visual function with IOP lowering in some patients.


 was and remains based on knowledgeable personalization of care, skillfully delivered. 

This includes awareness of the loose relationships between findings, such as intraocular pressure, and how patients function and feel. 

Anchoring diagnosis and treatment to what is important to patients was not well done in 1975, and there is still much room for improvement in 2020.


Innovation, change has dominated the glaucoma specialty over the years.

Glaucoma 45 years later: Much changed, much unchanged

I found myself fascinated by a 1983 paper by Steve Trokel, MD, in the 

 in which he used an industrial excimer laser to make patterns in cadaver animal eyes. I had done some research with Trokel while I was in medical school at Columbia University College of Physicians and Surgeons in New York, New York. 

I contacted Trokel and told him that I would love to be involved. I knew that there were very limited facilities at Columbia for animal research; at Louisiana State 

 (LSU), I had access to a large vivarium, the Delta Primate Center in Covington, Louisiana. 

It was owned and operated by Tulane University; LSU used it as well. So in 1984, Charles Munnerlyn, PhD, Trokel, and I began working together to develop laser-vision correction. Steve Klyce, PhD, a professor of ophthalmology at LSU, soon joined the team and became an important member.



Improving LASIK outcomes with biomechanical analysis 


Munnerlyn brought an industrial excimer laser to the lab, and we ablated thousands of plastic test blocks before moving on to cadaver animal and human eyes. 

As we progressed, we performed the procedure on living rabbit and monkey eyes. Through our years of work we were able to refine the hardware, software, surgical technique, and perioperative regimen.

There was a point when the rabbits were developing such extremely elevated, thick anterior corneal scars that the project seemed doomed. 

In one week, I lost my research coordinator and my technician. They gave the same reason for quitting: the excimer project was too depressing for them to continue to come to work every day. 

The hyperplastic scars decreased dramatically, however, when we increased the number of steps in our closing diaphragm (there were no flying spots yet, no trackers). 

When we had 5 steps in the ablation sequence, I would shoot for a few seconds, then hand-crank the diaphragm to its next position, then shoot again, and repeat. When we increased the number of steps to 40 and automated the process, it made a big difference in outcomes.

Procedures set a new horizon in refractive surgery


So progress was challenging for our team, but an unexpected opportunity arose in 1988. Alberta Cassady was a 62-year-old woman with cancer of the orbit, requiring exenteration; this would, of course, require the removal of the globe, the eyelids, and the contents of the orbit.

 She would be left with a large, deep, skin-lined socket. With a massively disfiguring procedure looming, and a poor prognosis even with the surgery, Cassady bravely offered to let our team perform experimental surgery on her eye. We did not ask Cassady to do this; she volunteered, which stunned us.

Because her cancer surgery was looming, time was of the essence. After receiving emergency permission from the Food & Drug Administration (FDA), we rushed Cassady past the monkey cages, and on March 25, 1988, I had the honor of performing the world’s first laser-vision correction procedure, PRK, in the eye of a living human subject at the Delta Primate Center. 

The research team watched her heal on a daily basis, right up until exenteration 11 days later. The refractive outcome was right on target, and the pathology report showed the early healing pattern that we now know so well.

Sadly, Cassady lost her battle to cancer. Her bravery and generosity in the face of such tragedy provided vital information that allowed the FDA to accelerate the approval process. 

Even though it is usually only wealthy donors who have facilities named after them, our team demanded that LSU allow them to name our laser facility after such a brave and selfless woman.


The FDA was so impressed by the daily postoperative evaluations, the refractive outcome, and the histological specimen that they allowed the team to start the blind eye human trials immediately, rather than more months and years of monkey trials. 

Laser-vision correction has come far, but it all started with the selfless act of one brave woman. Looking back on the procedure we performed on Cassady so many years ago, I am so proud and excited to see how far laser vision correction has come.


With LSU’s permission, we brought the excimer laser across Lake Pontchartrain from Covington to New Orleans to start the blind eye study. LSU was afraid that the argon fluorine gas would leak from the laser and kill everyone, however, so they placed the laser in a trailer outside the main building. Our team was very disappointed, and a bit embarrassed, to march patients into a trailer.

 It turned out to be a blessing in disguise, because we were located 5 feet from the university’s trash compactor. When the compactor was in operation, our trailer shook very gently, giving us much smoother ablations than we deserved to get (no flying spots or trackers yet, remember). 

All the patients did well, but those who were treated on the days that the compactor was working did even better. So, we figured it out: smoother ablations are better.


Astigmatism management software proving to be accurate, precise

Without trackers, we were forced to try some creative ways to stabilize the eyes. We first had a steel column—with 20 curved teeth at the end—that dropped down out of the laser and was screwed into the limbus. 

This draconian method worked, but we were afraid that a frightened patient might jump off the gurney and leave their eye behind, tethered to the laser.

Next we tried a suction ring with 4 fluid-filled chambers around the annulus. Each had a tiny bubble of air, so they were, in effect, 4 carpenters’ levels. As I fired the laser, Klyce would move my hand into a position where all 4 carpenters’ levels indicated that I was parallel to the floor. 

We added retrobulbar injections, and on rare occasion, lateral canthotomies, to be sure that we had enough room for the large 4-chamber suction ring. Eventually, flying spot lasers with trackers were introduced, as well as other refinements.



Astigmatism: A ‘clear-as-mud’ concept to patients

The rest is history
Since that first PRK procedure was performed in 1988, our original team has contributed to, and still contributes to, significant advances in laser-vision correction. 

Of course, PRK has evolved dramatically and is popular all over the world, including the US; in some countries, it is the most popular form of laser-vision correction. The latest iteration of PRK, epi-Bowman’s keratectomy (EBK), is the best yet with postoperative comfort and speed of return of vision that is competitive with LASIK.

The most prevalent type of laser-vision correction, however, is LASIK, which was introduced a decade after PRK by Ioannis Pallikaris, MD, of Greece; it is one of the most commonly performed elective surgeries, with more than 28 million procedures performed worldwide. 

Now, LASIK is commonly performed using all-laser femtosecond technology. When combined with advanced wavefront, topographic, or customized technology, laser-vision correction—both LASIK and PRK—can provide visual results that often surpass 20/20.



McDonald is clinical professor of ophthalmology at both NYU Langone Medical Center, New York, New York and Tulane University Health Sciences Center, New Orleans, Louisiana, and in practice with OCLI Vision, Oceanside, New York. McDonald is a consultant for Johnson & Johnson Vision and ORCA Surgical.

Advances in laser-vision correction provide visual results that often surpass 20/20.

Celebrating a pivotal moment in  laser-vision correction history

This article was reviewed by Sharmina Alauddin, MD



An artificial intelligence (AI)-based telemedicine platform for screening and early diagnosis of 

has been validated in a prospective trial, said Sharmina Alauddin, MD, at the 2020 Association for Research in Vision and Ophthalmology (ARVO) virtual meeting.

The deep learning algorithm’s (iPredict.health, iHealthScreen Inc USA) performance for classifying fundus images was evaluated using the gradings from expert human readers as the reference standard. 



Teaching AI algorithms to identify corneal pathology: The future is now



The analyses showed that the AI-based platform had 88.67% accuracy, 86.57% sensitivity, and 90.36% specificity.

“The results of our trial show that the tool is now ready for clinical use and potential deployment for remote telemedical use,” said Alauddin, a clinical research associate at the New York Eye and Ear Infirmary of Mount Sinai, New York, New York.

Alauddin and colleagues investigated the AI-based system’s performance in detecting and stratifying severity of 

 as a means of facilitating early diagnosis to improve patient prognosis.

“It is well known that AMD is a major cause of blindness among adults aged 50 years and older in developed countries,” Alauddin said. “If we are able to diagnose 

by screening in any clinical setting, we could start treating it early and thereby reduce the number of patients who become blind from their disease.”

Algorithm detects, stratifies severity of disease, facilitates early diagnosis. 


Ophthalmology Times: October 15, 2020

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