Physicians and health systems are challenged to provide appropriate care for the ever-increasing number of patients with diabetes and its complications, such as diabetic retinopathy (DR) and diabetic macular oedema (DMO). Tunde Peto, MD, PhD, Professor of Clinical Ophthalmology, Queen’s University Belfast, Belfast, Northern Ireland, and Clinical Lead for Diabetic Eye Screening in Northern Ireland and Medical Retina Consultant, offered some practical advice to address some of these challenges.

Diabetes and DR: Making progress in the global epidemic

The Diabetic Retinopathy (DR) Barometer Study

 analyzed data from over 4,000 patients and 2,000 doctors worldwide showing just how difficult living with and managing diabetes can be. The study results showed that almost 40% of patients describe the long wait times for an appointment as a barrier to eye examinations. 

About 80% of responders said that diabetes and DR and DMO impacted their ability to function in daily life, making driving, working, and completing the most basic household tasks difficult to impossible. Twenty percent reported that their visual impairment resulting from DR and DMO made managing diabetes difficult; and 69% described days during which they experienced poor physical/mental health. 

These difficulties in some settings might be compounded by the fact that as high as 1 in 5 ophthalmologists said that they did not receive specific training in diagnosing DR and DMO; and 44% of care providers did not have or use written protocols for managing diabetic eye disease and related visual loss. 

Prof Peto believes education, timely diagnosis, and treatment are the key components for preventing visual loss and preserving vision. Working together with patients and patient organization and co-developing education material will raise awareness of the disease. Diabetic eye screening programs can significantly address the problems associated with late diagnosis of DR and DMO leading to timely treatment and consequently better quality of life.

Diabetes during pregnancy linked to high refractive error in offspring

Complications associated with diabetes develop over a long period and regular monitoring can identify most patients at a stage in which treatment is most beneficial. DR and DMO lend themselves to image-based monitoring.

Physicians have an excellent understanding of diabetes-related eye changes, starting with the Airlie House Classification of DR.

 Landmark studies such as the Early Treatment Diabetic Retinopathy Study and the Diabetes Control and Complications Trial established a good understanding of the disease process.

 DR classification has been based on the presence of characteristic features in the eye or color fundus imaging of microaneurysms, hemorrhages, vascular abnormalities, and new vessels, and for DMO on these changes and exudates and macular fluid.

Diabetic macular edema: Treatment overview

“With advances in imaging technologies, we now have the opportunity to refine these and add further disease features to match our current understanding of the disease, its progression, and the potential response to treatment. Diabetes-related blindness still increases by 8% annually, so working with patients, care givers, public health agencies, and the healthcare sector, our patients with diabetes will have a better chance of retaining their vision and live a productive life,” Prof Peto concluded.

1. Cavan D, Makaroff L, da Rocha Fernandes J, et al. The Diabetic Retinopathy Barometer Study: Global perspectives on access to and experiences of diabetic retinopathy screening and treatment. Diabetes Res Clin Pract 2017;129:16-24; DOI: 10.1016/j.diabres.2017.03.023

2. Wu L, Fernandez-Loaiza P, Sauma J, et al. Classification of diabetic retinopathy and diabetic macular edema. 

3. Early Treatment Diabetic Retinopathy Study Research Group. Grading diabetic retinopathy from stereoscopic color fundus photographs--an extension of the modified Airlie House classification. ETDRS report number 10. Ophthalmology 1991;98:786–806.

Diabetes Control and Complications Trial Research Group

 S, Lachin J, et al. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. N Engl J Med1993;329:977-86; doi: 10.1056/NEJM199309303291401

Articles

Health systems are challenged to provide appropriate care for the ever-increasing number of patients with diabetes and its complications, such as diabetic retinopathy and diabetic macular oedema.

Key to beating diabetes is better understanding for ophthalmologists

Geographic atrophy (GA) imposes a heavy clinical and humanistic burden on patients with dry age-related macular degeneration (AMD), according to first author Dr Daniel Jones an employee of Apellis Pharmaceuticals.

Jones discussed the topic at the EURETINA 2021 Virtual Congress.

According to Jones, this advanced form of dry AMD, which has the potential to cause irreversible blindness, currently has no approved treatment and clinicians have no ways to prevent or slow progression, estimate the risk, or determine patient prognosis.

The estimated incidence of GA in the US is about 1.9/1000 and in older patients that rate increases to 4.3/1000.

It has been estimated that from 12% to 20% of GA cases end up with severe loss of vision, which severely impacts patients’ ability to care for themselves, perform chores, and navigate successfully outside the home without assistance.

Jones and colleagues undertook a literature review from January 1, 2015, to August 11, 2020, to assess the clinical and humanistic burden of GA already reported. They searched databases (PubMed, Embase, and Cochrane Library) during those dates as well as conference abstracts for 2019 to 2020.

The investigators found that in addition to the 12% to 20% of patients with GA who have severe loss of vision, almost a third of patients lose a minimum of 2 lines of vision during a 2-year period.

Compared with patients without GA, the vision-related function and health-related quality of life are poor in patients with GA, according to Jones.

The investigators noted that the results of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25), a tool that is often used to measure patient quality-of-life parameters, has found that patients with GA have significantly lower NEI VFQ-25 composite scores and lower subscale scores for near activities, distance activities, dependency, driving, social functioning, mental health, role difficulties, color vision, and peripheral vision versus individuals without GA, Jones said.

GA naturally impacts patient independence, and the inability to continue to drive is a particular concern for patients.

It also is associated with increased anxiety and depression, likely because patients lose the ability to take care of themselves and decreased vision prevents them from performing their daily tasks.

An important finding concerns ease of mobility.

“Patients are more likely to experience falls and fractures as a result of their impaired vision;

 study reported that 9% of patients with GA had a fall or fracture during a 12-month period,” Jones explained.

Based on these findings, the investigators concluded that GA imposes significant clinical and humanistic burdens on this patient population and loss of vision has a detrimental effect on many aspects of patients' lives.

The researchers emphasized the need for additional study to gain a better understanding of the GA burden experienced by patients.

During a presentation at the EURETINA 2021 Virtual Congress, Dr Daniel Jones discussed GA and emphasized the need for additional study to gain a better understanding of the burden experienced by patients.

Exploring the clinical and humanistic burden of geographic atrophy

A team of investigators in the UK has found that 1 injection of brolucizumab (Beovu, Novartis) treatment can result in a median improvement in visual acuity (VA) of 10.5 letters.

The investigators also found that the drug was well tolerated by patients with neovascular age-related macular degeneration (nAMD), according to first author Dr Cristina Cristian from the Department of Ophthalmology at Leeds Teaching Hospitals National Health Service Trust.

The drug was approved recently in the UK for treating nAMD. An advantage found in clinical trials was that the results achieved with injections at 8- or 12-week intervals were non-inferior to treatment with aflibercept (Eylea, Regeneron Pharmaceuticals Inc.) administered every 8 weeks.

According to Cristian, speaking at the EURETINA 2021 Virtual Congress, the advantages of 12-week dosing is a reduction in the number of patient visits and injections.

This is particularly important during the COVID-19 pandemic when maintaining social distancing is key to health and safety.

Cristian and her colleagues conducted a retrospective observational study to assess the efficacy and the risk profile of brolucizumab intravitreal injections in patients with an insufficient response to aflibercept characterized by persistent disease activity and unstable VA despite frequent therapy or disease control but a heavy treatment burden.

The charts of 35 patients (age range, 66-93 years; 51% women) with nAMD who were treated with brolucizumab from April 2020 to April 2021 were reviewed.

For all patients, the best-corrected VA, central retinal thickness, and intraocular pressure were measured; all patients underwent a complete ophthalmic examination at baseline and the last follow-up after the brolucizumab injection.

The patients received a total of 102 injections of brolucizumab; they had received from 3 to 62 previous aflibercept injections (median, 17; median injection interval, 6 weeks).

The median VAs before and after the brolucizumab injection were 57 and 67.5 letters, respectively; the respective central retinal thickness measurements were 337 μm and 436 μm.

The investigators reported that the treatment was well tolerated with no adverse events.

“The median VA improvement after the first injection was 10.5 letters despite the median increase in the central retinal thickness of 112.5 μm after the first dose of brolucizumab,” Cristian concluded. “No intraocular inflammation or vascular retinitis was detected in this case series.”

She also advised that conclusions about long-term results cannot be drawn.

In a presentation at the EURETINA 2021 Virtual Congress, Dr Cristina Cristian noted that an injection of brolucizumab treatment in patients with neovascular age-related macular degeneration led to a median improvement in visual acuity (VA) of 10.5 letters and the drug was well-tolerated.

Brolucizumab injection improves vision in eyes with neovascular AMD

Videos

Dr Ramin Tadayoni discusses the myopia panel at the EURETINA 2021 virtual meeting.

Worldwide pathological myopia discussed by panel at EURETINA 2021

Dr Grazia Pertile discusses the highlights of her presentations on the management of retinal folds after retinal detachment and the role of the anterior vitreous as a cause of recurrent retinal detachment.

Role of anterior vitreous, managing retinal folds in retinal detachment cases

Prof. Carel B. Hoyng, of the Radboud University Medical Center, Department Ophthalmology, Nijmegen, The Netherlands, discusses his presenation regarding macula dystrophies, including Stargardt disease, Best disease, X-linked retinoschisis, and the peripherin-2 (PRPH2) gene.

Prof Carel B. Hoyng discusses his presenation regarding macula dystrophies, including Stargardt disease, Best disease, X-linked retinoschisis, and the peripherin-2 (PRPH2) gene.


Analysis of macula dystrophy classifications

In a presentation at the EURETINA 2021 Virtual Congress, Dr Anat Loewenstein discussed optimizing optical coherence tomography (OCT) and how physicians can determine with even more accuracy precisely what is happening in patients’ eyes with neovascular age-related macular degeneration (nAMD) because of the potential afforded by application of artificial intelligence (AI).

Loewenstein is professor and director of the Department of Ophthalmology at Tel Aviv Medical Center, the Sidney A. Fox Chair in Ophthalmology, and vice dean, Sackler Faculty of Medicine, Tel Aviv University, Israel.

OCT is a major step forward in patient diagnosis, treatment, and monitoring but shortcomings remain. For example, physicians routinely make qualitative assessments of the presence and degrees of intraretinal/subretinal fluid and pigment epithelial detachments, but these are not precise assessment that are likely to result in poor inter-grader agreement and intra-grader consistency; OCT also provides the central subfield thickness, but the retinal fluid and neural tissue are not considered separately.

As Loewenstein pointed out, In neovascular AMD, it is important to distinguish between retinal fluid localization in the intraretinal and subretinal compartments and their volumetric information for informing retreatment decisions and predicting visual outcomes.

One technology to quantify OCT data, according to Loewenstein, is the Notal home-based OCT Analyzer (NOA), a machine learning algorithm that distinguishes normal morphologic features from elevated or distorted contours to quantify macular fluid of OCT volumes. The NOA quantifies intraretinal/subretinal fluid on Spectralis and Cirrus spectral-domain OCT devices. Both algorithms display their respective fluid output in nanoliters, which allows repeatable measurements and precise monitoring of disease activity.

“Recent advances in machine learning and deep learning have resulted in development of software that can process routinely acquired spectral-domain OCT data and precisely determine the location and volumetric information of macular fluid within different tissue compartments,” she said.

The software then can automatically generate multiple quantitative metrics related to macular fluid variables that may provide substantial advantages to research and clinical practice.

According to Loewenstein, using volume instead of thickness, separating fluid volume from neural tissue volume, distinguishing between intraretinal and subretinal fluid and monitoring dynamics over time might improve OCT’s ability to predict visual acuity changes.

• Because of the importance of OCT in assessing nAMD parameters, for which the fluid volumes in the retina are generally the key biomarkers, the availability of software that can analyze them quantitatively, automatically, and at scale is paramount.

• In practice, the ability to extract quantitative metrics of exudative activity from OCT scans is an important advantage over qualitative descriptions.

• By eliminating low intra-grader consistency and inter-grader agreement, exudative activity can be compared more meaningfully between sequential visits and visits that are widely separated of the same patient, or between patients, regardless of the individual physicians’ discretion.

• Quantitative metrics may result in better recordkeeping and visualization of exudative activity; the values from each visit can be recorded facilitating graphs of fluid volume plotted over time based on changes in treatment intervals, drugs, and doses.

• AI methods allow assessments and comparisons to be made separately for intraretinal/subretinal fluid and pigment epithelial detachments.

• Not all exudative activity is equal regarding visual prognosis and determining retreatment decisions.

• Future studies may lead to refined retreatment protocols possibly incorporating more nuanced approaches according to fluid compartment/volume.

• Algorithms that identify and quantify fluid types should help facilitate these approaches.

“AI tools may lead to more tailored treatment, ideally so that individuals achieve optimal visual outcomes with as few injections and visits as possible,” Loewenstein concluded. “This might help address some of the shortfall in visual outcomes that has consistently been observed between real-world practice and clinical trials.”

Loewenstein is a consultant to Notal Vision.

During a presentation at the EURETINA 2021 Virtual Congress, Dr Anat Loewenstein discussed how artificial intelligence can optimize optical coherence tomography.

AI for nAMD: Capturing more information from OCT

Gene replacement therapies for inherited retinal degenerations have shown promise in experimental disease models and are being tested in RPE65-associated Leber congenital amaurosis (approved in 2017) and Leber hereditary optic neuropathy, among others.

In addition to this research, Dr José-Alain Sahel and colleagues are involved in another line of research to benefit patients with inherited retinal degenerations with the hope of avoiding the challenges posed by gene replacement therapies, i.e., extensive genetic heterogeneity and dominant transmission.

“Gene-independent strategies could offer promising treatment avenues for these blinding diseases,” Sahel, chairman of the Department of Ophthalmology, and director of the University of Pittsburgh Medical Center Eye Center University of Pittsburgh, said during a presentation at the EURETINA 2021 Virtual Congress.

According to Sahel, cones are critical to vision and preserving them may save vision in patients with inherited retinal degenerative diseases. The focus of his team’s work, rod-derived cone viability factor, promotes cone survival by stimulating aerobic glycolysis.

In previous work, Sahel, with Saddek Mohand-Said, MD, and Thierry Léveillard from the Institut de la Vision, Paris, demonstrated in a murine model of retinitis pigmentosa that rod transplantation delayed cone loss, which depends on functioning rod photoreceptor cells. These finding could benefit patients with retinitis pigmentosa and other inherited retinal diseases (trial in preparation by SparingVision).

Optogenetics involves use of artificial photoreceptors from specific retinal cells to restore vision by transferring a gene that encodes for a light-sensitive protein that causes neuronal cells to respond to light stimulation (GS030, GenSight Biologics). This technology combines gene therapy and a medical device to restore retinal light sensitivity by modifying and training retinal ganglion cells to act as photoreceptor, Sahel explained.

The PIONEER Study is the first trial to test how GS030 optogenetic therapy works in 9 patients with end-stage retinitis pigmentosa. Patients received 1 intravitreal injection in the eye with the worse vision. The primary endpoint was the safety and tolerability of the treatment at the 1-year timepoint.

The study also is evaluating he effects of 3 doses of the treatment. Three patients were injected with the lowest dose in March 2019, 3 with the medium dose in February 2020, and 3 with the highest dose in June 2020 and June 2021.

The injections are part of the combined therapy that includes the use of goggles that project light onto the retina. An extension cohort is planned for the end of 2021. Thus far, the therapy has been well tolerated up to 2.5 years after the intravitreal therapy. The most frequent adverse event was anterior chamber or intermediate intraocular inflammation that responded to steroids in 5 of the 9 patients.

Sahel reported that 1 patient had partial recovery of visual function after this treatment.

 He was the only one who could perform training during the COVID-19 pandemic. Others are now training. There is some hope that this treatment can benefit patients with many types of retinal degenerations included age-related macular degeneration.

1. Sahel J-A, Boulanger-Scemama E, Pagot C, et al. Partial recovery of visual function in a blind patient after optogenetic therapy

 Nature Med 2021;27:1223-9; https://doi.org/10.1038/s41591-021-01351-4

During a presentation at the EURETINA 2021 Virtual Congress, Dr José-Alain Sahel explains that optogenetics involves the use of artificial photoreceptors from specific retinal cells to restore vision by transferring a gene that encodes for a light-sensitive protein that causes neuronal cells to respond to light stimulation.

Optogenetic therapy for retinal degeneration shows potential of gene-independent therapeutic strategies 


Dr Javier Zarranz-Ventura, a vitreoretinal consultant at 
Institut Clínic de Oftalmologia (ICOF), Hospital Clínic de Barcelona andInstitut de Investigacions Biomediques August Pi i Sunyer (IDIBAPS), discusses the key highlights from his presentation on a clinical investigation of suitable naïve versus pretreated DMO patients, and what it means for future research.

Dr Javier Zarranz-Ventura discusses the key highlights from his presentation on a clinical investigation of suitable naïve versus pretreated DMO patients, and what it means for future research.

Comparison of suitable naïve versus pretreated DMO patients


Dr Jennifer Sun, associate professor of Ophthalmology, Harvard Medical School; chief at the Center for Clinical Eye Research and Trials, Joslin Diabetes Center, explores the question of whether ophthalmologists should be using anti-VEGF agents to treat patients with nonproliferative diabetic retinopathy (NPDR).

Dr Jennifer Sun explores the question of whether ophthalmologists should be using anti-VEGF agents to treat patients with nonproliferative diabetic retinopathy (NPDR).

Should NPDR patients be treated with anti-VEGF agents?

Signs and symptoms of Alzheimer’s disease in the retina, optic nerve and the more posterior afferent visual system in the temporal and parietal lobes may point physicians to a diagnosis of Alzheimer’s disease earlier than previously realised, according to Dr Robert C. Sergott, director of the Neuro-Ophthalmology Service at Wills Eye Hospital and founding director and CEO of the Annesley EyeBrain Center at Thomas Jefferson University in Philadelphia, Pennsylvania, United States.

Dr Sergott pointed out the importance of being aware of the—often—subtle signs and symptoms in patients 55 years and older. With diseases such as Alzheimer’s disease and Parkinson’s disease, patients may present first to an ophthalmologist rather than a neurologist because of the associated visual disturbances.

Dr Sergott described a 68-year-old man who presented with progressive field constriction for 2 years and the inability to drive at night for approximately 1½ years. The patient described seeing oncoming lights when driving as starbursts.

Constricted visual fields may be an initial presentation of possible Alzheimer’s disease. However, the differential diagnosis is large and includes retinal degenerations; quinine toxicity; central retinal artery occlusion; end-stage glaucoma or papilloedema; confluent optic disc drusen; bilateral occipital lobe infarctions; non-physiological response; and cognitive impairment on automated perimetry.

Dr Sergott explained that visual field constriction implicates a visual field defect in the retina, optic nerve or occipital lobe; the photophobia, a problem in the retina; and night blindness and depth perception, a retinal or cortical issue. Consideration of the three locations suggests that there may be more of a retinal or a cortical problem, or both.

“Alzheimer disease affects them all: i.e., the retina, optic nerve and the visual system posterior to the lateral geniculate,” he said. The patient’s history was positive for prostate cancer and basal and squamous cell cancers, without metastases; hypertension; and hyperlipidaemia.

“A rule to live by in neuro-ophthalmology is to determine if the patient’s problem at hand is caused by the cancer recurrence, especially with breast cancer, or cancer therapy,” Dr Sergott emphasised. The patient’s ocular examination was unremarkable, with 20/40 vision bilaterally.

Interestingly, the patient could see only the test Ishihara plate, although he had no history of colour blindness. The acquired loss of colour vision could be in the cones, optic nerve or cortical system.

“This provides a subtle hint of an afferent visual problem. Colour vision measures contrast sensitivity,” Dr Sergott said. “Using low-contrast visual acuity [VA], a deficit worse than 20/40 might be identified.”

Optical coherence tomography imaging was unremarkable but showed slight flattening, with the fovea-macular contour slightly broadened. Fundus autofluorescence also showed no striking abnormality suggestive of early Alzheimer’s disease.

Multifocal electroretinography (ERG), however, showed an almost isoelectric tracing in the right eye despite 20/40 vision. In the left eye, multifocal ERG abnormalities were present but was not as pronounced as in the right eye.

Cranial MRI showed both non-specific changes and that paraneoplastic autoantibodies and the lumbar puncture cerebrospinal fluid profile were negative. Automated perimetry showed an inferior quadrantanopia in the left eye and a more subtle defect in the right eye. This localisation pattern was in the right parietal temporal lobe.

“From this testing, we know that this patient has brain disease in the right parietal temporal lobe,” Dr Sergott explained. “The multifocal ERG results indicated the presence of retinal disease. This proved to be an extensive process in the visual system.”

In addition to the constricted visual fields, colour vision deficit and abnormal ERG, the patient’s history showed dissatisfaction with the results of cataract surgery despite 20/40 bilateral VA and a depth perception of only 40 seconds of arc. “One reason for dissatisfaction postoperatively with a good Snellen VA may be Alzheimer’s disease,” he said.

“The root of the dissatisfaction may be subtle problems with difficulty reading and finding words and mild short-term memory loss.” Other clues are that the patient never arrived alone at appointments and often did not answer questions directed to them, Dr Sergott added.

Patients who present with predominantly visual symptoms may have posterior cortical atrophy.

However, Dr Sergott cautioned physicians about recognising patients who present with mildly disrupted memory and functioning, which may point to other findings suggestive of a more global deficit of visual processing. These may include a progressive decline in visuospatial, visual perception and literacy skills appearing in patients who are on average 50 to 65 years of age.

Experts disagree about whether posterior cortical atrophy is a pure form of Alzheimer’s disease or a separate entity. Lewy body dementia and prion disease may also have similar visual symptoms.

Dr Sergott summarised the various ophthalmological findings that ophthalmologists should prioritise when confronted with similar patients to the one described. The presentations of Alzheimer’s disease include the unhappy patient with good VA after cataract surgery and, in patients who have not had recent cataract surgery, loss of colour vision, loss of depth perception and photoreceptor dysfunction manifesting as glare and night blindness.

Dr Sergott also advised physicians to be alert to patients with visual field defects who have trouble with the automated perimetry test, especially with repeated attempts. Patients may also present with a homonymous hemianopsia but a normal MRI scan. This clinical presentation should alert ophthalmologists and neurologists to the possibility of Alzheimer’s disease.

“When such patients present, Alzheimer’s disease should be suspected. Hopefully, during 2021 some treatments will become available,” Dr Sergott said. “[As with] most treatments, they will work better the sooner they are instituted before the disease destroys most of the brain and a large segment of the retinal and optic nerve function. Ophthalmologists may be the key to get the diagnostic process moving.”

Dr Sergott added that he believes that the multifocal ERG may be the most sensitive test to identify retinal abnormalities in patients with dementia syndromes.

This article is adapted from Dr Sergott’s presentation at the Ohio Ophthalmological Society’s virtual annual meeting in February. He has no financial interest in this subject matter.

Subtle changes in the retina, optic nerve and visual processing system may reveal early signs of Alzheimer’s disease and enable prompt initiation of treatment.

Diagnosing Alzheimer’s disease: Ophthalmologists have role in early detection

Myopia is the most common refractive defect of the eye, affecting substantial proportions of adult populations; in one UK study, it was found to affect 49% of adults.

 The exponential increase in the prevalence of the condition is sparking increased interest in the geometric properties of the conjunctival-scleral tissue.

Generally referred to as short sightedness, myopia is an ametropia characterised by an eye that is too long for its optical system (cornea and lens). In recent years, there has been growing concern about the sharp rise in the prevalence of myopia in the juvenile population, and this has increased the need for research and development of new techniques to control axial elongation of the eye.

Myopia progression can be slowed with multifocal and orthokeratology lenses

 and post-mortem studies in humans have shown that the sclera is more extensible in high myopes than emmetropes, and that weakening of the scleral structure is related to the elongation of the eye, 

 examination of the geometric properties of the anterior sclera in eyes with different levels of myopia may improve our understanding of the variations in the anterior eye properties associated with increased ocular length.

The risk of suffering from diseases such as glaucoma or maculopathies increases very significantly as myopia increases. Therefore, it is important to understand the weakening procedure that takes place in the sclera, leading to progressive eye elongation, and to see whether this process also generates changes in the anterior portion of the structure (covered by the conjunctiva), which can be measured clinically. In this way, geometric factors at the level of the sclera might predict which cases are more susceptible to scleral changes.

OCULUS joins International Myopia Institute in mission to raise myopia awareness

Considering the existing technology for the clinical evaluation of the corneo-scleral geometry,

 as well as the comparison and validation of the main technologies applied in the clinic,

 Fourier domain profilometry (Eye Surface Profiler [ESP], Eaglet-Eye) stands out as being a reasonable way of studying the relationship between myopia and corneo-scleral geometry. Measurement with this device is minimally invasive and quickly captures all the data necessary to characterise such geometry with high levels of precision.

We recently conducted a prospective study to analyse the relationship between corneo-scleral geometry, measured with this type of technology, and the axial length of the eye, defining the differential aspects existing in myopic eyes and developing prediction models of the axial length of the eye based on clinical data.

In total, 64 eyes of 32 healthy participants (mean age 33 years) were evaluated in the Optometry Clinic of the University of Alicante, Spain, including complete analysis of the anterior segment, analysis of visual function and evaluation of the corneo-scleral topographic profile with the ESP system. The study methods adhered to the tenets of the Declaration of Helsinki and were approved by the ethics committee of the University of Alicante (Exp UA-2019-08-28).

Bi-sphere corneo-scleral topographic map obtained in an emmetropic eye (left) and a myopic eye (right).

(Figure courtesy of Dr Laurent Bataille, Dr Ainhoa Molina-Martín and Dr David P. Piñero)

A statistically significant and moderate-to-strong negative association was found between the axial length and the difference between temporal and nasal sagittal heights for different chord lengths (from 

 < 0.001 for 15-mm chord length). This suggests that nasotemporal sagittal height asymmetry has potential as a biomarker of myopic changes.

It is possible that the decrease in nasotemporal sagittal height asymmetry in myopic eyes is due to different insertion of the medial rectus muscle and the lateral rectus muscle

 combined with the noticeably lower rigidity of the sclera in such eyes.

 Specifically, there is a rearward displacement of the insertion site of the medial and lateral rectus muscles in myopic eyes,

 with rotation of the eyeball around the same nasal and anterior point to its geometric centre regardless of the axial length of the eye.

Exploring possibilities of myopia prevention and control in the US

A multiple linear regression analysis showed that the axial length could be predicted with acceptable levels of precision by means of a linear equation relating refractive, corneal and corneo-scleral variables, although the variables involved for the prediction seem to differ in right and left eyes. Specifically, the following linear equations for predicting the axial length (AL) were obtained:

< 0.001, adjusted R2: 0.843): AL=15.62-0.27 ×SE+0.99 ×CD+2.77 ×HOA RMS-1.77 ×MinSH14; and

< 0.001, adjusted R2: 0.730): AL=37.20-0.40 ×SE-0.33 ×Km+0.086 ×CD-3.96 ×HOA RMS

where SE is spherical equivalent; CD, corneal diameter; HOA RMS, high order aberration root mean square; MinSH14, minimum sagittal height for a chord length of 14 mm; and Km, mean keratometry.

SMILE procedure offers low enhancement rate after nomogram adjustment

The slight difference between the linear models used to predict axial length from the anterior segment parameters for the right and left eyes may be related to differences in the ocular globe between eyes: the asymmetry of the axial length between them has been shown to increase with increasing axial length.

These models should be considered as a preliminary approach that provides information on the potential value of the geometry of the anterior sclera for the prediction of axial length. Future studies should validate and refine these models in large samples including subjects with different ethnicities.

Multifocal lenses for presbyopia in eyes with previous corneal surgery

The analysis of the relationship between the corneo-scleral geometry measured with Fourier domain profilometry and the axial length of the eye has shown that nasotemporal sagittal height asymmetry may be a good biomarker of myopic changes. More studies are needed to clarify this issue as well as determine how these corneo-scleral parameters change during myopia progression.

Laurent Bataille, PhD, Ainhoa Molina-Martín, PhD, and David P. Piñero, PhD

Dr Bataille and Dr Molina-Martín are post-doctoral researchers from the Group of Optics and Visual Perception of the Department of Optics, Pharmacology and Anatomy, University of Alicante, Spain. Dr David Piñero is a senior researcher and lecturer from the same group and is responsible for the advanced optometry unit of the Department of Ophthalmology of Vithas Medimar International Hospital, Alicante, Spain. The authors have no proprietary or commercial interest in the medical devices that are mentioned in this manuscript.

1. Pan C-W, Ramamurthy D, Saw S-M. Worldwide prevalence and risk factors for myopia: Prevalence and risk factors for myopia. 

2. McBrien NA, Jobling AI, Gentle A. Biomechanics of the sclera in myopia: extracellular and cellular factors. 

3. Backhouse S, Gentle A. Scleral remodelling in myopia and its manipulation: a review of recent advances in scleral strengthening and myopia control. 

4. Vurgese S, Panda-Jonas S, Jonas JB. Scleral thickness in human eyes. PLoS One 2012;7:e29692.

Characterization of the geometric properties of the sclero-conjunctival structure: a review.

6.Bataille L, Molina-Martin A, Piñero DP. C

omparative analysis of two clinical diagnostic methods of the corneoscleral geometry.

. 22 Mar 2021. DOI:10.1097/ICL.0000000000000785.

Bataille L, Molina-Martin A, Piñero DP. Intrasession repeatability of corneal, limbal and scleral measurements obtained with a Fourier transform profilometer.

 23 Nov 2020. DOI: 10.1016/j.clae.2020.11.002.

8.Bataille L, Molina-Martín A, Piñero DP. 

Relationship between axial length and corneo-scleral topography: a preliminary study.

9.Haładaj R. Normal anatomy and anomalies of the rectus extraocular muscles in human: A review of the recent data and findings. 

10. McBrien NA, Gentle A. Role of the sclera in the development and pathological complications of myopia. 

11. McMonnies CW. An examination of the relation between intraocular pressure, fundal stretching and myopic pathology: The relation between IOP, fundal stretching and myopic pathology. 

12.El-Fayoumi D, Bahgat N, Khafagy M, et al. Horizontal extraocular muscle insertion site in relation to axial length using swept-source anterior segment OCT. 

13. Clark RA, Demer JL. The effect of axial length on extraocular muscle leverage. 

14. Rajan MS, Bunce C, Tuft S. Interocular axial length difference and age-related 

A recent prospective study analysed the relationship between corneo-scleral geometry and the axial length of the eye to develop preliminary prediction models of the axial length of the eye based on clinical data.

The relationship between myopia and conjunctival-scleral geometry

The 39th Congress of the European Society for Cataract and Refractive Surgery (ESCRS) plans to open its doors for the first time since the COVID-19 pandemic began at the RAI Congress Centre in Amsterdam, the Netherlands, from 8–11 October 2021. In-person attendance at this much-anticipated yearly event is sure to be an appealing prospect to many. And for those who are unable to attend in person, the Congress will also be held virtually, making the chance to participate in some capacity a reality for all.

So, what is in store for attendees this year over the four action-packed days? At the time of going to press, the ESCRS had not released the full, in-depth programme, however, a range of symposia, programmes, video sessions and workshops will be on offer and are discussed in this brief preview article. There will also be a daily exhibition, giving people the chance to experience the latest technologies in ophthalmology and providing the ideal location for ophthalmologists and researchers to network with their peers.

editorial advisory board members: Dr Albert Augustin, professor of ophthalmology and chairman of the Department of Ophthalmology at the Karlsruhe Municipal Hospital, Germany, and Dr Paolo Fazio, head of the refractive surgery service of the Catanese Centre of Medicine in Catania, Italy, to gain their insights into the topics on the agenda at this year’s event. Read on to find out more!

The Main Symposium to be held in the morning of the opening day of the Congress will be on the interesting-sounding topic “Managing Herpetic Keratitis”. There will also be a Clinical Research Symposium entitled “Stem Cells: Basics and Clinical Perspectives”, taking place after lunch. Two further symposia planned for the afternoon are the “JCRS” (Journal of Cataract and Refractive Surgery) and the “ISRS” (International Society for Refractive Surgery) sessions.

A Video Session due to be held between 5.15pm and 6.45pm will showcase “Challenging Cases”, a topic that proves popular every year at the ESCRS, as ophthalmologists seek to learn how to manage the more difficult patients and/or surgeries. Learning opportunities will also present themselves during the three courses planned for Day 1, whose topics have yet to be disclosed. Friday also marks the day the Exhibition Hall will open (between 9am and 5pm).

The more junior ophthalmologists among attendees will have the chance to network and learn tips and tricks in the “Young Ophthalmologists Programme”, which begins on the Saturday. Dr Augustin comments: “This format is becoming increasingly popular, since young ophthalmologists, and especially young surgeons, now have a new platform to discuss problems or situations in the clinical practice which are unique for beginners and may not be a topic suitable for other formats. This is true for both scientific and surgical questions.”

Meanwhile, the Clinical Research Symposium will be on “Advances in Corneal Cross-Linking”, which is currently a very hot topic. “Corneal crosslinking is an increasingly standardised procedure, with new accelerated protocols that reduce the duration of treatment with similar results to standard ones,” says Dr Augustin.

Emphasising the importance of the “Selecting Advanced IOLs” Main Symposium taking place, Dr Fazio comments: “This is a Symposium that will probably be held for several ESCRS meetings to come since the list of advanced IOLs is becoming more crowded by the day.”

“MIGS: The Evidence-Based Approach” will be the topic of the second of the Main Symposia taking place on the Saturday. Dr Augustin says: “The introduction of MIGS has simplified the approach to glaucoma surgery. A review of recent evidence is important to improve the outcomes in terms of both IOP reduction and complication rate.”

For those wishing to participate in courses, attendees will have the option to either do so in person or virtually, with both types (seven in-person and two virtual) being on offer on Saturday. Free Paper sessions are also expected to place before the day wraps up with a video “Award Session”, between 6.30pm and 8pm.

Sunday is shaping up to be a very busy day at the ESCRS, with two Symposia taking place in the morning—on “Imaging Techniques of the Anterior Segment and Beyond” and “Practical Digital Ophthalmology”—and a couple taking place after lunch.

Referring to the afternoon’s Research Symposia on “Cost Effectiveness and Value-based Healthcare: Have They Entered Ophthalmology?”, Dr Augustin points out: “Limitations on resources make the cost-effectiveness of any procedure very important for all of us. The information in this session should help ophthalmologists to engage with both payers and hospital administration staff.”

Regarding the Main Symposium covering “Enhancements after Refractive Surgery”, he comments: “Enhancement of refractive surgery is also a hot topic because refractive patients have very high expectations, which very often cannot be met with the first procedure. Thus, enhancement procedures can be necessary to produce superior results.”

“Euro Times Satellite Education Symposia” also appear in the schedule at various times throughout the day and there is also a Symposium entitled “IIIC” (Intraocular Lens Implant Club) at the end of the day. The IILC is a group of international specialists which will, no doubt, present the newest developments in IOL design. Dr Augustin believes that development in the field of IOLs is in “constant turmoil, with the introduction of ever more precise lenses for the correction of refraction errors and the management of presbyopia”.

With educative opportunities remaining a major theme at the Congress, nine courses, two of which are offered virtually, are planned to be held at varying times. The Video Session will cover surgical methods, which is always a good opportunity for ophthalmologists to hone their techniques and learn from peers. Sunday also marks the last day the Exhibition is open.

On the final day of the Congress, glaucoma is the subject of the two “Masterclasses” in the morning, which demonstrates the importance that cataract and refractive surgeons need to have a high level of understanding of this disease entity. There will also be a “Hyperopia Workshop”, a total of five in-person courses and a session discussing the work of the non-profit organisation Orbis Flying Eye Hospital; a teaching hospital on board a flight, which delivers eyecare to low- and middle-income countries.

“Don’t miss the ORBIS session,” Dr Augustin advises. “This charity project was established many years ago. You will see and hear the newest activities of this group.”

Dr Augustin also strongly advises attending the “CSCRS Symposium”. “This symposium of the ‘united cataract surgeons of the world’ will provide you with latest news on cataract surgery from a global perspective,” he says.

The final day will be rounded up, as has become something of a tradition at the ESCRS Congress, with the “Best of the Best”, a session that will enable attendees to go away with the main pearls of the event.

The 39th Congress of the European Society for Cataract and Refractive Surgery (ESCRS) will meet at RAI Congress Centre in Amsterdam, the Netherlands, from 8–11 October 2021. The Congress will also be held virtually, making the chance to participate in some capacity a reality for all.