According to the Merriam-Webster dictionary, a pirate is “one who commits or practices piracy,” which is defined as “an act of robbery on the high seas.” We at PIE Magazine believe even more devastating visual robbery can occur in the posterior segment.
We’ve all heard tales of piracy, from the likes of Disney’s romantic and adventurous Pirates of the Caribbean movies, to the truly terrifying real stories of piracy occurring off the shores of Africa. But regardless if the tale is real or make-believe, the theme remains the same: Someone is being robbed of something.
This led us to think about eyeballs (which we do often at PIE Magazine) . . . and how often people are “robbed” of sight – whether due to disease, lack of early detection or availability of treatment. Like pirates who pillage gold, there are ‘PIErates’ who plunder vision.
According to PIE Magazine, a PIErate is “something that robs patients of precious sight; this includes aggressive pathologies, lack of access to care and/or lack of treatment.”
So, what are these PIErates? Below, three heroic ophthalmologists from Asia-Pacific talk about which “PIErates of the Posterior Segment” they’d like to see walk the plank and be forever vanquished to Davy Jones Locker.
Diabetic Retinopathy (DR)
“In my opinion, the biggest threat for a patient’s loss of sight is diabetic retinopathy.” – Dr. Rajan
Prof. Dr. Mohan Rajan, Chairman and Medical Director, Head of Cataract and Retina Services, Rajan Eye Care Hospital, T. Nagar, Chennai, India.
Diabetic retinopathy (DR) is considered the most common cause of vision loss among people with diabetes and a leading cause of blindness among working-age adults. This is especially true in India, which is set to emerge as the diabetic capital of the world. According to the World Health Organization, by 2030, 79.4 million Indians will be affected by diabetes mellitus (DM) – more than any other country. This means that DM-related complications like DR will also rise: Almost two-thirds of all type 2, and nearly all type 1 diabetics are expected to develop DR.1
DR occurs in diabetic patients with chronically high blood sugar. This results in damage to the tiny blood vessels in the retina, which may cause them to leak fluid or hemorrhage – which causes vision loss. In its most advanced stage, complications can lead to irreversible damage and vision loss. Early treatment can prevent the pathology’s progression, so awareness and accessibility to professional care is critical.
“The main reason for this alarmingly growing pathology is lack of awareness and the growing diabetes [epidemic] in the majority of population, especially the younger population,” said Dr. Rajan. He believes that creating mass awareness of diabetes and its complications, as well as detecting the disease at an early stage, are essential to saving sight.
According to a 2013 study, awareness of DR in India is very poor. This Indian population-based study found that over half of the non-medical respondents were not aware of risk factors for DR. In addition, 80 percent of these respondents believe annual eye exams were essential, but only 43.5 percent had ever visited an ophthalmologist.2 Low awareness coupled with issues surrounding access to care creates a volatile situation.
Dr. Rajan agrees that lack of access to care contributes to visual loss and believes the first step is to manage DR and control diabetes through patient education, appropriate medication, dieting and exercise. In the vast Indian subcontinent this can be a challenge due to a low doctor-to-patient ratio, and barriers to treatment including cost and lack of access.
“Lack of treatment definitely contributes to loss of sight,” said Dr. Rajan. “Various reasons such as unavailability of tertiary eye care to patients is a major reason for the growth of the disease, and of course in a country like India, the cost of treatment plays a vital role and is difficult for the lower socio-economic group.”
However, innovations in mobile imaging and technology are presenting an opportunity for more access to affordable care. “Mobile imaging technology will go a long way in detecting diabetic retinopathy at the very early stages and initiating appropriate treatment and present vision loss,” continued Dr. Rajan.
New breakthroughs in artificial intelligence (AI) are also showing promise in diagnosis of DR. “This wonderful technology can enable us to detect and prevent future disease by taking several photographs of the retina, fundus and studying the retinal vasculature,” explained Dr. Rajan.
His insights are echoed by a study published in June 2018. The authors’ objective was to assess the role of AI-based automated software to detect DR and sight-threatening DR (STDR) by fundus photography taken using a smart-phone-based device, then validating the results against ophthalmologist’s grading. In the study, 301 patients with type 2 diabetes underwent retinal photography with Remidio’s “Fundus on phone” (FOP), a smartphone-based device, at a tertiary care diabetes center in India. [Editor’s note: For more on Remidio’s FOP, see page 26.]
In the end, retinal images of 296 patients were graded. DR was detected by the ophthalmologists in 64.5% and by the AI software in 68.6% patients, while STDR was detected in 37.8% and 49.3% patients, respectively. The AI software showed 95.8% (95% CI 92.9-98.7) sensitivity and 80.2% (95% CI 72.6-87.8) specificity for detecting any DR and 99.1% (95% CI 95.1-99.9) sensitivity and 80.4% (95% CI 73.9-85.9) specificity in detecting STDR with a kappa agreement of k = 0.78 (p < 0.001) and k = 0.75 (p < 0.001), respectively.3
These results led the authors to conclude that “automated AI analysis of FOP smartphone retinal imaging has very high sensitivity for detecting DR and STDR and thus can be an initial tool for mass retinal screening in people with diabetes.”
Dr. Rajan is cautiously optimistic about AI as a diagnostic tool: “This modern software application may need corrections and up gradation to understand the disease in a better way.”
To retire this PIErate, all technological advances are welcome: “My advice would be making the best treatment affordable and accessible to the patients,” he concluded.
“Mobile imaging technology will go a long way in detecting diabetic retinopathy at the very early stages and initiating appropriate treatment and present vision loss.” – Dr. Mohan Rajan
Polypoidal Choroidal Vasculopathy (PCV)
“If left untreated, recurrent subretinal hemorrhage from PCV can eventually result in irreversible loss of vision.” – Dr. Wagle
Dr. Ajeet Madhav Wagle, Medical Director and Senior Consultant Ophthalmologist, International Eye Cataract Retina Centre, Singapore
Polypoidal choroidal vasculopathy (PCV) was first described by Yanuzzi et al. in 1990 as a distinct clinical entity characterized by persistent, recurrent serous leakage and hemorrhage in the macula.4 Prior to this designation, PCV was poorly understood. The pathology, which is a unique subtype of “wet” or neovascular age-related macular degeneration (nAMD), is a significant cause of vision loss in the middle-aged and elderly, impairing central vision and affecting daily activities like reading, recognizing faces and driving.
“The clinical course of PCV varies in severity depending on the extent and location of the disease, ranging from spontaneous resolution to recurrent serosanguinous retinal pigment epithelial detachments (PEDs), subretinal hemorrhage and scarring,” explained Dr. Wagle. “Typically, PCV presents with sudden onset unilateral blurred vision, central or paracentral scotoma and/or distortion of central vision.”
He added that PCV shares many risk factors with nAMD, including: age (generally occurring in individuals aged 50 to 65), genetic predisposition and a predilection for pigmented races.
And while PCV and nAMD may share risk factors, their treatment and prognosis differ considerably. “PCV needs to be differentiated from typical nAMD using appropriate ocular imaging techniques such as indocyanine green angiography (ICGA),” said Dr. Wagle. “A strong clinical suspicion is required to diagnose PCV. In the presence of characteristic clinical features of PCV, multi-modality retinal imaging is essential to confirm the diagnosis . . . ICGA is a must.”
As a prompt and accurate diagnosis is necessary to treat PCV, lack of access to the correct imaging modalities can result in delayed treatment, and irreversible loss of vision. This is another scenario where mobile imaging devices can help save sight: “Digital imaging technologies and teleophthalmology consultations can now allow sharing of information with retina specialists and accredited digital image reading centers to help with a prompt and accurate diagnosis of the condition,” said Dr. Wagle.
Other PCV-related PIErates include lack of access to care, high cost of treatment and poor patient compliance – all of which can result in a less than favorable visual outcome.
“Fortunately, the management options for PCV have rapidly expanded over the last decade. Symptomatic patients with PCV are managed effectively with anti-vascular endothelial growth factor (anti-VEGF) injection therapy, PDT and/ or thermal laser photocoagulation. These modalities are used either alone or in combination to treat the disease,” said Dr. Wagle.
[Editor’s Note: See page 44 for results from year two of the PLANET study, which evaluated the safety and efficacy of intravitreal aflibercept (IVT-AFL) monotherapy compared with IVT-AFL plus active PDT in patients with PCV.]
“Digital imaging technologies and teleophthalmology consultations can now allow sharing of information with retina specialists and accredited digital image reading centers to help with a prompt and accurate diagnosis of the condition.” – Dr. Ajeet Madhav Wagle
Recurring Pathology, Late Detection
“It’s tough to treat recurring PCV – very difficult in some cases – and it’s quite common,” said Dr. Ruamviboonsuk.
Dr. Paisan Ruamviboonsuk, President of the Royal College of Ophthalmologists of Thailand (2013-2016) and Assistant Director of the Centre of Medical Excellence (Rajavithi Hospital), Thailand.
Dr. Ruamviboonsuk attributes PCV’s affinity for recurrence to being a PIErate: “Some cases of PCV are like pirates to me – sometimes treatment doesn’t work well, and vision keeps dropping. Or we have cases that respond very well to treatment in the first couple of years, but then it recurs. We still don’t know the reasons why some cases have recurred after years of inactivity.”
A study published in the Japanese Journal of Ophthalmology evaluated the recurrence of polypoidal lesions after photodynamic therapy (PDT) for polypoidal choroidal vasculopathy (PCV). The authors found that “recurrence of PCV occurs in about 40% of eyes treated for PCV even after a long period of inactivity, so careful follow-up is needed.”5
Another study followed 47 eyes of 47 patients with PCV for two years after their first PDT treatment. At the final visit, while visual acuity (VA) was preserved or improved in 79% of the eyes, recurrence of lesions was noted in 64%. The authors concluded that “patients with PCV need to be followed for long periods of time after PDT because of the high incidence of polypoidal lesion recurrence.”6
“This is why PCV is like a PIErate to me . . . we still don’t know why it recurs,” said Dr. Ruamviboonsuk.
In addition to the pathology’s recurrence, Dr. Ruamviboonsuk also emphasizes the need for early detection to preserve VA. “If it’s a small lesion, and the patient comes to you early, that’s okay. We can treat them with PDT, combined PDT and anti-VEGF, or anti-VEGF alone. But if the patient comes to you a little bit late, you can have trouble.”
Sight Savers: The Anti-PIErates
Although there are many sight-stealing PIErates, there are also “sight-savers,” those whose work preserves vision through medical or surgical care, research or technological innovation.
For example, Prof. Dr. Rajan notes that Rajan Eye Care Hospital has multiple projects working to eradicate blindness: “The most important is ‘The Blind Free India Project,’ which takes care of avoidable and preventable blindness.”
They also have a teleophthalmology mobile van called “Nethra Vahana” that caters to the population within 150-kilometers of Chennai. The van is equipped with state-of-the-art diagnostic equipment, imaging technology and laser therapy for diabetic retinopathy (DR). In addition, there is also the “Slum Vision Project,” where they go to the slums and test for diabetes and DR.
Dr. Wagle also routinely volunteers his services, performing free cataract surgeries for deserving patients in rural parts of India every year. He also works to raise awareness of age-related macular degeneration (AMD) in Singapore: “I’ve led many annual nationwide AMD Awareness Week campaigns in Singapore over the past decade.” Dr. Wagle was awarded several public health education grants to fund these awareness campaigns.
References:
1 Gadkari SS, Maskati QB, Nayak BK. Prevalence of diabetic retinopathy in India: The All India Ophthalmological Society Diabetic Retinopathy Eye Screening Study 2014. Indian J Ophthalmol. 2016; 64(1): 38–44.
2 Ramasamy K, Raman R, Tandon M. Current state of care for diabetic retinopathy in India. Curr Diab Rep. 2013;13(4):460-468.
3 Rajalakshmi R, Subashini R, Anjana RM, Mohan V. Automated diabetic retinopathy detection in smartphone-based fundus photography using artificial intelligence. Eye (Lond). 2018;32(6):1138-1144. [Epub 2018 Mar 9.]
4 Yannuzzi LA, Sorenson J, Spaide RF, Lipson B. Idiopathic polypoidal choroidal vasculopathy (IPCV). Retina. 1990; 10(1):1-8.
5 Yamashiro K, Tsujikawa A, Nishida A, Mandai M, Kurimoto Y. Recurrence of polypoidal choroidal vasculopathy after photodynamic therapy. Jpn J Ophthalmol. 2008;52(6):457-462. 6 Akaza E, Mori R, Yuzawa M. Long-term results of photodynamic therapy of polypoidal choroidal vasculopathy. Retina. 2008;28(5):717-22.
