DEFERIPRONE IN GLAUCOMA MANAGEMENT

 

Currently, lowering of intra-ocular pressure (IOP) remains the main therapeutic option for the treatment of glaucoma. However, studies have shown that despite adequate control of IOP a large number of patients develop loss of visual function. This has spurred researchers to look for new options for the management of glaucoma.

According to Dr. Qui N. Cui, Assistant Professor of Ophthalmology at the Perelman School of Medicine, affiliated to the University of Pennsylvania, USA, “All available treatments for glaucoma target IOP control, which is not sufficient to prevent vision loss in a significant number of patients”.

Prof. Qui N. Cui

Apoptosis, pyroptosis, and necroptosis are classical forms of regulated cell death that play important roles in various diseases. Ferroptosis was a regulated cell death described by Dixon et al. who used elastin to treat cancer cells containing oncogene mutations. They found an iron-dependent and lipid peroxidation-triggered cell death pathway, which relies on iron-generated reactive oxygen species. In the eye, this process can lead to acute retinal degeneration.

There is increasing evidence supporting the association between ferroptosis and glaucoma. A clinical study involving 17,476 participants showed that a high serum ferritin level was associated with increased risk and morbidity of glaucoma. Upon facilitated release of ferric iron by increased ferritin, a redox reaction is triggered. This iron-induced oxidative stress is suggested to contribute to optic nerve degeneration in glaucoma. 

SEE LINK: https://ourgsc.blogspot.com/search?q=ferroptosis

Also, iron-related genes transferrin, ceruloplasmin and ferritin were shown to be upregulated in a monkey model of glaucoma, and in glaucomatous human post mortem eyes, suggesting a role for iron-induced oxidative stress in glaucoma pathogenesis.

Antioxidant administration has been shown to rescue rodent RGCs exposed to extended periods of IOP elevation. These associations suggest iron chelation may slow glaucoma progression.

Deferiprone (DFP), is an orally-administrated iron chelator approved by the FDA for treating patients with iron overload. Oral administration of DFP protects against iron-induced retinal degeneration by reducing retinal iron levels in ceruloplasmin/hephaestin double-knockout and hepcidin knockout mice, both of which exhibit age-related retinal iron accumulation and increased oxidative stress.

In a study performed by Dr. Qui and colleagues, a mouse model of elevated IOP was used in which one eye had experimental ocular hypertension and the other was kept as normotensive control. Half the cohort received oral DFP (1 mg/ml in the drinking water), the other half did not and served as controls. After 8 weeks, Brn3a immunolabeling of flat-mounted retinas was used for manual RGC quantification. Axon counts were obtained from thin sections of optic nerves using the AxonJ plugin for ImageJ.

DFP administration was found to be protective against RGC and optic nerve loss in the setting of elevated IOP. These results suggest that iron chelation by DFP may provide glaucoma neuroprotection.

A side-effect of DFP administration is reversible agranulocytosis, which requires weekly blood evaluations. Therefore, the utility of DFP as long-term treatment for a slowly progressive neurodegenerative condition like glaucoma remains to be seen. Alternatives to systemic DFP administration may lie in local, targeted ocular administration and/or other iron chelators.

REFERENCE:

Cui QN, Bargoud AR, Ross AG, Song Y, Dunaief JL. Oral administration of the iron chelator deferiprone protects against loss of retinal ganglion cells in a mouse model of glaucoma. Exp Eye Res. 2020 Apr;193:107961. doi: 10.1016/j.exer.2020.107961. Epub 2020 Feb 8. PMID: 32045598; PMCID: PMC7584350

Dixon SJ, Lemberg KM, Lamprecht MR, Skouta R, Zaitsev EM, Gleason CE, Patel DN, Bauer AJ, Cantley AM, Yang WS, Morrison B 3rd, Stockwell BR. Ferroptosis: an iron-dependent form of nonapoptotic cell death. Cell. 2012 May 25;149(5):1060-72. doi: 10.1016/j.cell.2012.03.042. PMID: 22632970; PMCID: PMC3367386.

HELICOBACTER PYLORI ASSOCIATED GLAUCOMA

Helicobacter pylori (H. pylori) is a spiral-shaped and gram-negative micro-organism that affects the epithelial mucosa of the stomach. In that site it usually causes peptic ulcer, gastritis and cancer.

Ocular manifestations of H. pylori infection include glaucoma, central serous chorioretinopathy (CSR), blepharitis, and uveitis.

It is presumed that H. pylori causes glaucoma by various mechanisms, including the release of various pro-inflammatory and vasoactive substances such as reactive oxygen species, through arteriosclerosis-induced increased platelet activation and aggregation, and impact on the trabecular meshwork cell apoptotic process.

H. pylori infection is also responsible for induction of oxidative DNA.

Cross-reactivity between antibodies to H. pylori and the ciliary epithelium and antibody-induced apoptosis has also been speculated.

Glaucoma patients have a common genetic factor that makes them more susceptible to H. pylori infection.

A meta-analysis involving 24 studies was performed to look into the probable association of H. pylori with glaucoma. Out of those 7 were cohort and 17 case-control studies. [1] 

This meta-analysis showed a statistically significant relationship between H. pylori infection and glaucoma, and further analysis showed that this positive relationship is observed in primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) and pseudo-exfoliative glaucoma (PXG).

In studies by Shahram Ala et al., and also by Kountouras, H. pylori eradication treatment positively affected glaucoma management. The results showed that intraocular pressure decreased significantly after eradication treatment in the intervention group. [2] [3]

These studies suggest that this cause can be considered in certain areas where H. pylori infection is endemic.

REFERENCES:

1. Ezzati Amini E, Moradi Y. Association between helicobacter pylori infection and primary open-angle glaucoma: a systematic review and meta-analysis. BMC Ophthalmol. 2023 Sep 11;23(1):374. doi: 10.1186/s12886-023-03111-z. PMID: 37697285; PMCID: PMC10496366.

2. Ala S, Maleki I, Araghi AS, Sahebnasagh A, Shahraki A. Helicobacter pylori eradication in the management of glaucoma. Caspian J Intern Med. 2020;11(2):143.

3. Kountouras J, Mylopoulos N, Chatzopoulos D, Zavos C, Boura P, Konstas AG, Venizelos J. Eradication of Helicobacter pylori may be beneficial in the management of chronic open-angle glaucoma. Arch Intern Med. 2002;162(11):1237–44

LOW VISION AIDS IN GLAUCOMA

 

Glaucoma is characterized by classical visual field loss patterns. In early glaucoma there is mainly restriction of the peripheral fields. But in later stages central vision is also impaired, affecting the quality of life of the glaucoma patient. However, there are some studies which have shown that even central vison can be affected early in the course of glaucoma. As visual deterioration develops, there occurs a situation in which usual visual rehabilitation methods such as glasses become ineffective. In such cases low vision aids (LVA) may prove helpful.

Overall, visual rehabilitative services include mobility training, adaptive skills training, low vision instruction career services and training, psychological counseling and others.

Some other useful links:

How to break bad news: https://ourgsc.blogspot.com/search?updated-max=2024-04-13T12:52:00%2B05:30&max-results=1&start=1&by-date=false

SPIKES protocol: https://ourgsc.blogspot.com/search?updated-max=2024-04-16T09:24:00%2B05:30&max-results=1&reverse-paginate=true

Low vision aids are devices which help people use their sight to better advantage. These aids fall into two categories, namely, optical and non-optical. The former includes optical lenses, such as magnifiers or telescopes. The non-optical devices include visors, filters, reading slits, stands, lamps and large print. The basic principle of all low vision optical devices is to magnify.

OPTICAL DEVICES:

1. Magnifying spectacles (high plus reading glasses) used for reading any material, writing and looking at objects from close range. The spectacle produces magnification of 1/4th of the power of the lens. For binocular corrections prism spectacles half eyed of full field with base in (to compensate for convergence angle of the eye) are used.

2. Magnifiers: Handheld low vision magnifiers are helpful for looking in a mirror, telling the time on a watch, and other quick viewing tasks. The ones with self-contained illumination can be used when surrounding illumination is dim. The low vision magnifiers that are mounted on a stand are useful for reading books and doing close-up work such as needlepoint and quilting.

3. Telescopes: These are prescribed for distance, near and intermediate tasks like reading signs, recognizing people, reading from blackboard at more than 2-meters distance, watching television, games or traffic signals. These can be hand held monocular, clip on, spectacle mounted, monocular or binocular, bioptic designs.

4. E-Scoop glasses: E-Scoop Glasses are custom designed optics that combine 5 unique optical characteristics to maximize the remaining vision of a low vision patient. These 5 optical features focus the image onto the part of the eye that is least affected by vision loss, thereby maximizing the patient’s current vision.

5. Envision glasses: Envision Glasses are AI-powered smart-glasses with an integrated camera and built-in speakers that speak out the visual world. It is a wearable device that significantly improves the daily life of people that are blind or have low vision. It provides an intuitive and easy way to access all kinds of visual information around them. 

6. IrisVision: These electronic glasses use a highly innovative assistive technology solution, which is registered with the FDA as a Class-1 medical device.

7. Acesight: It is a wearable LVA is based on ‘Augmented Reality’ technology. It offers an HD display floating before the eyes, through a pair of head-mounted goggles, which are connected to a controller through a wire. It provides up to 15X magnification, while the wired controller allows one to customize the colors and contrast. This electronic eyewear is designed to cater to the needs of people with visual acuity ranging from 20/100 to 20/800.

8. NuEyes Pro: It is a head-worn lightweight and wireless pair of smart glasses, which can be controlled either through a wireless handheld controller or a set of voice commands. A camera on the front of the glasses captures the image and displays it magnified inside of the lenses. These glasses provide up to 12X magnified images.

9. MyEye2: These are low vision electronic glasses designed to make reading, writing, recognizing faces and various other daily activities easier for visually impaired people. A light attachable camera distinguishes it from an ordinary pair of glasses, which is mounted on the frame of the glasses by the side.

NON-OPTICAL DEVICES:

1. Typoscopes are used to enhance images and reduce glare. Felt tipped pens, bold lined papers, writing guide, large print materials and adequate lighting on print are helpful methods in assisting vision by enhancing contrast. Reading stands are useful by providing a hands-free comfortable working distance.

2. Assistive Technologies: Desktop electronic magnifiers are low vision aids that display reading material placed on a tray. The person with low vision moves the reading material as needed and views it on a screen at a suitable height. Most of these magnifiers have an independent monitor, but others allow for connection to a TV or computer monitor. Often these devices are a bit heavy and therefore are not portable. There are portable low vision electronic magnifiers, which are of two main types. The handheld ones can be carried in a pocket or handbag, and are used to read labels in a grocery store or pharmacy, menus in a restaurant, credit card slips, price tags and more. The other type has a camera fixed to a stand. Therefore, a still image of the reading material can be taken and can be read later on a portable device.

Supernova magnifier

Juno Magnifier

LIMITATION: The non-availability of trained personnel as well as the financial cost and practicality of the LVAs remains a limitation for their usage in glaucoma clinics.

CARONIA GLAUCOMA CARD

 

The Amsler Grid chart, a commonly used method for detection of macular pathologies, has been utilized in detection of visual field (VF) defects in advanced glaucoma. [1]

However, a new card developed by Dr. Ronald Caronia, is apparently more efficacious in detecting scotomas and readily acceptable by patients with severe glaucoma compared to the Amsler grid. [2]

The Caronia Glaucoma Card (CGC) design incorporates a vertical and horizontal line and seven concentric circles corresponding to 1-degree arc at normal reading distance.

The 7 concentric circles surround a central ‘X’. The first circle surrounding the ‘X’ creates 1-degree of arc from the center, and each of the other circles creates an additional 1-degree arc from the previous circle.

The end result is a card which evaluates 7 degrees of peripheral field from fixation, giving the full extent of peripheral field testing to 14 degrees.

In a study conducted by Dr. Caronia, the patients were given a card on which the Amsler grid was printed on one side and the CGC on the other. The patients were asked to use either one or both tests to monitor their visual function on a weekly basis. Upon return, they were asked which test they preferred and if they appreciated or noticed any change in their scotoma.

The study reported that 30 patients out of 67 preferred the CGC (60%), while 8 patients preferred the Amsler grid (16%) for monitoring their VFs. Twelve patients found no difference between the 2 test designs (24%). [χ² (2, 50) =16.480, ρ=0.000]. Five patients noticed a change in their scotoma while using the card (5.8%, 5 of 86 eyes). All were exclusively using the CGC.

The report concluded that the CGC is a convenient and inexpensive tool to assess VF defects in glaucoma and has high acceptance by patients to monitor their glaucoma status.

REFERENCES:

1. Gessesse GW, Tamrat L, Damji KF (2020) Amsler grid test for detection of advanced glaucoma in Ethiopia. PLoS ONE 15(3): e0230017. https://doi.org/10.1371/journal.pone.0230017

2. Caronia RM. Caronia Glaucoma Card Versus Amsler Grid for Monitoring Patients With Advanced Glaucoma. J Glaucoma. 2024 Apr 1;33(4):277-287. doi: 10.1097/IJG.0000000000002336. Epub 2023 Nov 24. PMID: 38031281.

SPIKES Protocol

 

The SPIKES Protocol is a common template for breaking bad news for different morbid conditions, especially cancer. For the ophthalmologist, this can come handy in dealing with glaucoma patients.

The acronym SPIKES, stands for Setting up, Perception, Invitation, Knowledge, Emotions with Empathy, and Strategy or Summary.

It is helpful to be reminded that, although bad news may be very sad for the patients, the information may be important in allowing them to plan for the future.

S- SETTING UP:

An appropriate setting with as much privacy as possible is required to establish rapport with the patient and/or family. Any disturbing influences such as phones, TV or radio should be turned off. The HCP should ensure that there are no distractions from other staff members. Setting the stage for optimal communication by preparing what to say prior to the conversation is essential to successful communication. The rules of preferred body language for optimal communication including sitting while speaking, maintaining an open posture, and maintaining eye contact apply as the interview environment is considered.

P- PERCEPTION:

The HCP should obtain all relevant information, including medical facts regarding the patient’s condition prior to conducting the interview. It is better to follow the “before you tell, ask” axiom, and ask open-ended questions initially so as to get some idea about the patient’s understanding of the condition. Subsequently, the HCP can correct any misinformation and explain the situation to the patient, especially with regards to the irreversible loss of vision which has already occurred and the expectations for the future. But most importantly the HCP should be in a position to understand the feelings of the patient/family and direct them towards a more honest understanding of the situation. The challenge for all clinicians is to respect the level of information desired, but have the patient and family know enough so that they are able to provide informed consent for further testing and treatment.

I- OBTAINING THE PATIENT’S INVITATION FOR DISCUSSION:

Every person has a different coping mechanism for their illness. A majority might be interested in knowing the problem, why they developed glaucoma, if there are any ways to prevent further visual loss and the types of treatments available. Others do not wish to know the details and inform the HCP that they have faith in their management and would leave all those aspects for the doctor. If the patient does not want to know the detailed results, one must offer to address any queries that they may have in the future, once their mind is at ease, or provide the details with subsequent implications to a care provider or family/friend.

K- GIVING KNOWLEDGE AND INFORMATION TO THE PATIENT:

The first step in actually delivering the news is to “Fire a Warning Shot” and warn the patient and family that the incoming news is not good.

The sharing of bad news must be presented based on the assessed level of patient’s understanding, compliance, and wishes for disclosure. Instead of using technical language regarding tests such as visual fields or OCT, the HCP can devote more time on the basic aspects of glaucoma and how the condition is affecting his visual pathway and what treatment is doing to his condition. The actual sharing of the bad news should be done slowly so that the patient and family understand. Appropriate words, especially in a stage of diverse cultural pool, have to be carefully chosen.

E- ADDRESSING THE PATIENT’S EMOTIONS WITH EMPATHIC RESPONSES:

Responding to the patient’s emotions is one of the most difficult challenges of breaking bad news. Patients’ emotional reactions may vary from silence to disbelief, crying, denial, or anger. This creates a potentially awkward situation for the HCP, but this sense of awkwardness can be diminished through engaging in empathetic communication.

In cases of advanced glaucoma with a risk of snuff-out, the visual prognosis is poor. However, the doctor must avoid using phrases such as total blindness, and rather focus on revised therapeutic goals and expectations.

S- STRATEGY AND SUMMARY:

The main aim of the interview is to present a clear plan or strategy for the patient, keeping in view the patient’s perception of the condition and the prognosis. Studies have shown that patients who have a clear plan for the future are less likely to feel anxious and uncertain. The future management plan should be discussed by the HCP. This is legally binding in some situations.

Sharing responsibility for decision-making with the patient may also reduce any sense of failure on the part of the physician when treatment is not successful. The doctor must check that the patient does not misunderstand the efficacy or purpose of the treatment, e.g., that the vision loss or visual field loss that has already occurred will not be restored by any subsequent intervention. In glaucoma patients the idea that the vision could improve after surgery or laser has to be cleared.

Finally, the HCP can re-cap a summary of the discussion in order to reinforce the ideas discussed with the patient.

STRATEGIES FOR BREAKING BAD NEWS

 

A delicate situation encountered by physicians is when they are called to break negative or bad news regarding the disease to the patients and/or their families. “Bad news” may be defined as “any information which adversely and seriously affects an individual’s view of his or her future”.

For a healthcare-provider (HCP) treating glaucoma, this situation can occur during the initial consultations itself, when the visual prognosis is poor or guarded. Often, the patients consult an ophthalmologist when they are already in the advanced stage of the disease, in the hope of recovering their vision. While others, follow a path of slow deterioration, losing a major part of their visual field over time, despite adequate treatment by the ophthalmologist. 

For a HCP, good communication skills are an integral part of high-quality patient care. To be able to effectively convey bad news can be a significant factor in improving the quality of life of the patient.

Breaking bad news involves a twofold process of finding appropriate kind words and understandable terminology, and the secondary task of assessing how the patient and family are reacting, the degree of distress that the conversation is inducing, and the subsequent tailoring of information as the HCP responds to the assessment process. The last segment of this communication is to move the patient and family from the bad news to the future plans with realism and hopefulness.

In order of simplify the process of breaking bad news a few strategies are being used. These include the SPIKE, BREAKS and ABCDE protocols. The acronyms stand for SPIKE (Setting, Perception, Information, Knowledge, Emotions & empathy, Support), BREAKS (Background, Rapport, Explore, Announce, Kindling and Summarize), ABCDE (Advance preparation, Building therapeutic relationship, Communication, Dealing with patient/family, Encouraging emotional responses/outbursts & offering solutions).

The SPIKES strategy/protocol was designed by Walter Baile and colleagues at the University of Texas MD Anderson Cancer Center in USA, and is designed to offer HCPs an effective mechanism to break bad news. The protocol focuses on the following steps:

1. Establishing an appropriate setting.
2. Checking the patient’s perception of the situation prompting the news regarding the illness or test results. 
3. Determining the amount of information known or how much information is desired. 
4. Knowledge of the medical facts and their implication before initiating the conversation.
5. Exploring the emotions raised during the interview and responding with empathy. 
6. Establishing a strategy for support.

Subsequent posts on The Glog shall present in detail the features of the SPIKES strategy.

QLS-111

 

QLS‑111 is a molecule being investigated for its role in lowering IOP.

QLS‑111 is a novel topical formulation using Qlaris Bio’s ATP-sensitive potassium channel modulator platform originally developed by Dr. Michael Fautsch, PhD, professor of ophthalmology, biochemistry, and molecular biology at Mayo Clinic, in Rochester, Minnesota.

QLS-111 lowers IOP by relaxing vessels of the vascular and vascular-like tissues distal to the trabecular meshwork, thereby reducing distal outflow resistance and lowering episcleral venous pressure (EVP).

Thus, it is potentially suitable for treating primary open-angle glaucoma (POAG), ocular hypertension (OHT), and normal tension glaucoma (NTG).

EVP contributes up to 50% of total IOP. If unchecked, EVP may play a role in the inability to reach target IOP. Therefore, QLS‑111's complementary mechanism may offer a significant and synergistic advantage in managing IOP.

QLS-111 has demonstrated that it can work alone or in combination with several current glaucoma drug classes, indicating that its use with current medications will aid in the ability to achieve levels of IOP reduction that slow disease progression.

Qlaris Bio, Inc. (“Qlaris”), a clinical-stage biotechnology company targeting unmet needs in debilitating ophthalmic diseases, announced the initiation and dosing of two separate U.S. Phase II masked, randomized clinical trials investigating QLS‑111 in patients with ocular hypertension and glaucoma.

The company is initiating the following studies:

The Osprey study (NCT06016972) will assess the safety, tolerability, and optimal dose of QLS‑111 compared with vehicle alone in adult patients who have POAG and/or OHT. The efficacy of QLS-111 in lowering IOP will be assessed as a secondary endpoint of the trial.

The Apteryx study (NCT06249152) will evaluate the safety and tolerability, and measure the additive IOP-lowering efficacy, of QLS‑111 in combination with latanoprost versus latanoprost alone. Patients aged 12 years or older and who have POAG and/or OHT currently on latanoprost will be enrolled in the trial.

A few studies have demonstrated that treatment with QLS‑111 provides persistent lowering of IOP, maintains normal vascular integrity of the venous system, is well-tolerated, and thus far has shown it does not cause hyperemia. [Information from company website]

HYPODENSE HOLES & MICROCYSTIC MACULAR EDEMA

 

Apart from retinoschisis and PIRDs, discussed in previous posts, some other unusual features seen on OCT images in glaucoma patients are “hypodense holes” and “microcystic macular edema”.

In 2011, Xin et al., described “holes” within the RNFL of glaucomatous eyes on circumpapillary OCT scans. These holes appear as small round or oval regions of very low or absent (‘‘hypodense’’) reflectance, conspicuous in contrast to the normally strong reflectance produced by axons within the RNFL. The holes tended to occur immediately adjacent to a vessel. In Xin’s study, 33(16%) of glaucomatous eyes showed these holes but none were present in healthy controls.

Hypodense holes

Glaucomatous eyes can also have microcystic macular edema (or microcystic macular degeneration). These lesions are pseudo-cysts (lacunae or vacuolar inclusions) seen in the inner nuclear layer (INL) in the form of a perifoveal ring on OCT scans.

Microcystic macular edema

Two recent OCT studies have estimated the frequency of ‘‘microcystic macular edema’’ (i.e., finding pseudo-cysts within the INL) in glaucoma and documented the clinical characteristics of those cases. Brazerol and colleagues studied 218 glaucoma patients and observed INL microcysts in eight eyes (2.8%) of eight patients (3.7%).

Hasegawa and colleagues have also described microcystic lesions of the INL in glaucomatous eyes using OCT. They reported microcystic INL lesions in 6.0% (13 of 217) eyes with primary open angle glaucoma.

Among Hasegawa’s patients, a larger proportion of advanced glaucoma was seen associated with microcystic edema (P=0.013). There was also a significantly worse deviation in the VF mean deviation slope in eyes with microcysts (P=0.027).

REFERENCES:

Xin D, Talamini CL, Raza AS, de Moraes CG, Greenstein VC, Liebmann JM, Ritch R, Hood DC. Hypodense regions (holes) in the retinal nerve fiber layer in frequency-domain OCT scans of glaucoma patients and suspects. Invest Ophthalmol Vis Sci. 2011 Sep 9;52(10):7180-6. doi: 10.1167/iovs.11-7716. PMID: 21791587; PMCID: PMC3207719.

Brazerol J, Iliev ME, Höhn R, Fränkl S, Grabe H, Abegg M. Retrograde Maculopathy in Patients With Glaucoma. J Glaucoma. 2017 May;26(5):423-429. doi: 10.1097/IJG.0000000000000633. PMID: 28169924.

Hasegawa T, Akagi T, Yoshikawa M, Suda K, Yamada H, Kimura Y, Nakanishi H, Miyake M, Unoki N, Ikeda HO, Yoshimura N. Microcystic Inner Nuclear Layer Changes and Retinal Nerve Fiber Layer Defects in Eyes with Glaucoma. PLoS One. 2015 Jun 12;10(6):e0130175. doi: 10.1371/journal.pone.0130175. PMID: 26066021; PMCID: PMC4467090.

PARAVASCULAR INNER RETINAL DEFECTS (PIRDs) IN GLAUCOMA

 

Paravascular inner retinal defects (PIRDs) are spindle-shaped or caterpillar-shaped dark areas along the major retinal vessels. These lesions have been reported in eyes with high myopia and epiretinal membranes (ERM) previously. However, some recent studies have found an association of PIRDs with glaucoma and glaucoma-suspects. Results of these studies argue for glaucomatous damage as a factor that can cause PIRDs independently of ERM and/or myopia.

Muraoka termed this condition PIRD as it did not appear to be a simple cleavage of the inner retina and was often accompanied by a functional abnormality.

In contrast to nerve fiber layer defects associated with glaucoma, most PIRDs have irregular margins, and the widths are variable. The PIRDs are more frequently paravenous than para-arterial. They appear disconnected from the optic disc on ophthalmoscopy.

On red-free images, PIRDs appear as high-contrast retinal rarefactions.

These lesions are most frequently detected in the superior hemisphere and temporal area of the optic disc (Supero-temporally).

Goldmann perimetry often shows a visual field defect corresponding to the lesion. In Muraoka’s study the most common associated visual field defects were relative Bjerrum scotoma (in 75% [60 of 80]; 95% CI, 66%-85%) and nasal steps (in 59% [47 of 80]; 95% CI, 48%-70%).

On OCT scans, the PIRDs appear as cystoid or fissure like wide defects in the inner retina or underneath the major retinal vessels, often deviating into the vitreous cavity.

Sequential OCT examinations of the retinal vessels has shown that the lesions are remarkably widespread, and a broad defect in the paravascular inner retinal tissue is frequently observed.

REFERENCES:

Muraoka Y, Tsujikawa A, Hata M, et al. Paravascular Inner Retinal Defect Associated With High Myopia or Epiretinal Membrane. JAMA Ophthalmol. 2015;133(4):413–420. doi:10.1001/jamaophthalmol.2014.5632

https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2089676

Donald C. Hood, Nicole De Cuir, Maria A. Mavrommatis, Daiyan Xin, Hassan Muhammad, Juan Reynaud, Robert Ritch, Brad Fortune; Defects Along Blood Vessels in Glaucoma Suspects and Patients. Invest. Ophthalmol. Vis. Sci. 2016;57(4):1680-1686. https://doi.org/10.1167/iovs.15-18499.

https://iovs.arvojournals.org/article.aspx?articleid=2513120