May 11, 2022

The most important ophthalmology research updates, delivered directly to you.

In this week's issue

  • Anterior segment OCT biometrics describing angle and iris, but not gonioscopic scores, were predictive of progression of PAC suspect to PAC or AAC
  • Fluctuations in intraocular temperature were found to have diurnal and seasonal patterns in eyes with primary open-angle glaucoma
  • Photorefractive keratectomy improved developmental domains for children unable to tolerate traditional refractive correction
  • Transconjunctival administration of local anesthetic for lower eyelid surgery appears safe, with less discomfort and bruising than transcutaneous route

The biometric risk factors for progression to PAC glaucoma


Imagine the PRESSURE… Could you predict the angle closure offender in a line of suspects? Primary angle closure (PAC) is characterized by a narrow iridocorneal angle causing increased intraocular pressure (IOP) and/or evidence of anterior synechiae. Primary angle closure glaucoma (PACG) is PAC with optic nerve damage and/or visual defects. In contrast, primary angle closure suspect (PACS) is an early form of PAC with >1 quadrant with angle closure, but normal IOP and no synechiae. Early intervention can slow progression, so it is imperative to understand the risk factors. A prospective observational study was conducted on 643 subjects with untreated PACS to elucidate risk factors for progression to PAC or acute angle closure (AAC). Baseline examinations included gonioscopy, anterior segment optical coherence tomography and A-scan ultrasound. From a total of 643 PACS eyes, 34 (5%) progressed, with 4% progressing due to synechiae, <1% due to elevated IOP, and <1% due to AAC. In a continuous multivariable model, narrower angle opening distance, flatter iris curvature, and older age were associated with progression. However, smaller gonioscopy scores were not associated with progression. These results suggest that biometric measurements, including angle width, iris curvature, and age can predict PACS progression, but gonioscopy cannot. Practitioners can use this information to guide decision making for early intervention in PACS patients.

Diurnal and seasonal intraocular temperature variations in POAG

British Journal of Ophthalmology

If you can't handle the heat, get out of the angle: a nest thermostat for your eyes? While the exact pathophysiology of glaucoma is not fully understood, intraocular pressure (IOP), inflammation, oxidative stress, and mitochondrial dysfunction are commonly studied potential mechanisms. Intraocular temperature (IOT) has additionally been hypothesized to play a role in the pathogenesis of glaucoma, yet there is limited research on this topic due to technical limitations. This prospective, open-label, multicenter observational study analyzes IOT data obtained from an intraocular sensor in the ARGOS-2 trial.  Twenty-two eyes of 22 patients with primary open-angle glaucoma (POAG) who underwent cataract surgery with implantation of the eyemate-IO sensor presented with IOT diurnal variations with higher temperatures at night and lower temperatures in the middle of the day over 24 hours. The present study shows that IOT fluctuates significantly in eyes with POAG and follows a clear seasonal pattern. The study of IOT may cast light on several aspects of glaucoma pathophysiology, ocular perfusion, and IOP regulation. It remains unclear from study design whether the changes noted were due to artifacts from measurement or actual patient environment. These measurements should be interpreted with caution as the environmental temperatures recorded by the mesograph may reflect the storage conditions of the reader unit more than the temperature in the actual patient environment which may be influenced by artificial heating or cooling.

What role might PRK play for children with intellectual disabilities?

American Journal of Ophthalmology

Could correction of high refractive error using photorefractive keratectomy (PRK) improve development in children with intellectual disabilities? In this patient population, poor visual acuity can be a debilitating comorbidity that may make interacting with an unfamiliar world a challenging and scary prospect. While some children are able to utilize wearable correction, many may be unable or poorly adherent, which further contributes to visual isolation that could hinder their development. Researchers in this prospective case series used several developmental tests to determine the change in developmental quotient (DQ) of 16 children before and after treatment with PRK. Six months after having undergone PRK, the DQ showed significant improvement in the areas of expressive communication (4.51 ± 2.27), interpersonal relationships (9.45 ± 4.18), and coping (6.44 ± 2.10). After 12 months, several other domains showed a significant increase in DQ including receptive communication (8.04 ± 1.80), expressive communication (6.99 ± 2.27), written communication (9.28 ± 3.72), domestic skills (6.50 ± 2.43), interpersonal relationships (10.57 ± 4.17), and coping (8.41 ± 3.25). While including a relatively small number of subjects, this study demonstrates that PRK may be an important intervention for certain neurodevelopmental domains and boost overall quality of life in children unable to use traditional corrective methods.

Conjunctiva better than skin for administering local anesthesia?


Should you go through the skin or conjunctiva? Local anesthesia administered transcutaneously (Tskin) and transconjunctivally (Tconj) for lower eyelid surgery were compared for pain and safety levels. Thirty patients in this randomized trial underwent bilateral lower eyelid surgery for horizontal laxity and received Tskin anesthesia in one eye and Tconj in the other. The patients’ pain scores (scored subjectively by patients from 0-10) were lower for Tconj (3.90±2.28) than Tskin (5.33±2.23) and more patients receiving Tconj had lower scores of pain (56.7%) than did those that received Tskin (23.3%). Bruising (assessed objectively from 0-3) was slightly lower in the Tconj group, but there was no statistically significant difference. This study shows that Tconj is safe and less painful than the conventional Tskin administration of local anesthesia but may be of greater consideration in patients with lower eyelid laxity, which permits easy eversion and thus facilitates safe administration into the conjunctival space.


Show me the numbers: remote monitoring for AMD

Ophthalmology Retina

The early bird gets the worm…or at least better vision when diagnosing AMD progression! Age-related macular degeneration (AMD) is the leading cause of vision loss among elderly patients in the United States, with neovascular AMD (nAMD) responsible for more than 80% of AMD-related vision loss. Early detection of conversion from non-exudative AMD to nAMD is essential for timely treatment and preservation of visual acuity but requires patient attentiveness to their symptoms between clinic visits. To help with home monitoring, an artificial intelligence visual field analyzer known as the ForeseeHome (FSH) device was created to objectively quantify perceived visual distortions in patients with AMD. In this retrospective cohort study, 3334 eyes with non-exudative AMD used the FSH home device for an average duration of 3.1 years. Out of the 285 eyes that converted to nAMD during the study, 52% were referred for in-person follow up by their FSH device and over 80% maintained functional vision of 20/40 or better. These findings demonstrate the potential benefits of early diagnostics from home monitoring and their effects on visual acuity. As longer-acting treatments for nAMD lead to less frequent office visits, remote monitoring may become more relevant in the future. 

Question of the Week

A 46-year-old man presents with decreased visual acuity in both eyes for the past 2 days and a severe headache with neck pain for the past 2 weeks. He reports difficulty processing certain details of sounds but denies hearing loss. Visual acuity testing was 20/40 OD and 20/60 OS. B scan demonstrates thickening of the posterior choroid.  Fluorescein angiography was significant for multiple hyperfluorescent spots with pooling of fluorescein in the subretinal space. Other associated images are shown below.
Which of the following statements is most accurate regarding this disease?

A. The presentation is consistent with the chronic form of the disease
B. ERG-b wave has a high sensitivity of detecting the disease
C. The presentation is consistent with the prodromal stage of the disease
D. Treatment plan should include inflammatory reduction & anti-VEGF therapy 

Keep scrolling for answer or click here

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Answer: D
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