The Horizontal Raphe of the Human Retina and its Watershed Zones

The Natural History of Retinal Sensitivity Loss in Diabetic Macular Ischemia over One Year Evaluated by Microperimetry

Background/Objectives: This one-year prospective observational study, conducted at two centers, aimed to report the natural history of retinal sensitivity (RS) loss in diabetic macular ischemia (DMI). Methods: Patients with stable-treated proliferative diabetic retinopathy (PDR) were recruited if there was evidence of DMI on optical coherence tomography angiography, defined as a foveal avascular zone ≥ 0.5 mm2 or parafoveal capillary dropout ≥ 1 quadrant. The minimal visual acuity required for performing microperimetry (MP) was ≥54 Early Treatment Diabetic Retinopathy Study letters (Snellen equivalent 20/80). The overall RS (oRS) and pointwise sensitivity (PWS) within the 3 × 3 mm macula were assessed at baseline and twelve months. A value <25 decibels (dB) was defined as impaired RS, and a decrease of 2 and 7 dB was regarded as mild and severe loss, respectively. Results: A total of 88 patients (97 eyes) were included. No statistically significant MP changes were detected at one year. However, 10% of the cohort lost oRS ≥ 2 dB, and 73% lost ≥2 dB PWS in ≥5 loci, whereas 1% lost oRS ≥ 7 dB, and 4% lost ≥7 dB PWS in ≥5 loci. The foveola and temporal parafovea were the most vulnerable to severe RS loss. Compared to their counterpart, eyes with baseline oRS ≥ 25 dB had significantly more RS loss in the macula and superior parafovea (55% versus 32% and 53% versus 28%, both p = 0.01). Conclusions: Rather than oRS loss, ≥2 dB loss in PWS in ≥5 loci is a more feasible outcome measure for clinical trials in DMI.

Longitudinal Changes in Peripapillary and Macular Vessel Densities in Glaucomatous Eyes With a Single-Hemifield Retinal Nerve Fiber Layer Defect

PRCIS

The peripapillary vessel density decreased significantly in the affected hemiretina compared with that in the intact hemiretina in glaucomatous eyes with a single-hemifield retinal nerve fiber layer defect.

PURPOSE

To evaluate the difference in the change rates of peripapillary vessel density (pVD) and macular vessel density (mVD) measured using optical coherence tomography angiography (OCTA) in glaucomatous eyes with a single-hemifield retinal nerve fiber layer (RNFL) defect.

MATERIALS AND METHODS

We performed a retrospective, longitudinal study of 25 patients with glaucoma who were followed up for at least 3 years, with a minimum of 4 visits after baseline OCTA. At each visit, all participants underwent OCTA examination, and the pVD, mVD were measured by removing the large vessels. Changes in the pVD, mVD, peripapillary RNFL thickness (pRNFLT), and macular ganglion cell inner plexiform layer thickness were investigated in the affected and intact hemispheres, and the differences between the 2 hemispheres were compared.

RESULTS

In the affected hemiretina, the pVD, mVD, pRNFLT, and mCGIPLT were reduced than that in the intact hemiretina (all, P < 0.001). The changes in pVD and mVD were statistically significant at the 2-year and 3-year follow-ups in the affected hemifield (all, P <0.05). However, pVD and mVD did not show statistically significant changes in the intact hemiretina throughout the follow-up visits. Although the pRNFLT decreased significantly at the 3-year follow-up, the macular ganglion cell inner plexiform layer thickness showed no statistical change at any follow-up visit. Compared with the intact hemisphere, pVD was the only parameter that showed significant changes throughout the follow-up period.

CONCLUSION

Although pVD and mVD decreased in the affected hemiretina, the reduction in pVD was significant compared with that in the intact hemiretina.

Paracentral acute middle maculopathy following coronary angiography

Purpose

To describe a case of paracentral acute middle maculopathy (PAMM) after coronary angiography.

Observations

A 65-year-old female patient exhibited a dense central scotoma 5 hrs after coronary angiography. She presented the next day to the retina clinic and received a complete visual examination including slit lamp biomicroscopy, dilated fundus examination, fluorescein angiogram (FA), spectral domain optical coherence tomography (SD-OCT) and OCT-Angiography (OCT-A). She was found to have the characteristic findings of PAMM including a hyperreflective band at the inner nuclear layer (INL) with extension into the inner plexiform layer (IPL) and outer plexiform layer (OPL) on imaging.

Conclusions and Importance

PAMM lesions can occur immediately following coronary angiography. The acute nature of the presentation and time to examination in this case lend further insights into the pathophysiology of PAMM. When patients undergo cardiovascular interventions and report new onset visual scotomas, the diagnosis of PAMM should be considered with referral for careful ophthalmic examination and work-up.

Multimodal Imaging, OCT En Face, and OCT Angiography of an Anomalous Retinal Artery: Case Report and Review of the Literature

The purpose is to study for the first time the vascular plexuses and the retinal nerve fiber layer and raphe of a patient with a very uncommon anatomical variation: an anomalous retinal artery supplying the whole macula. We used multimodal imaging, en face spectral-domain optic coherence tomography, and spectral-domain optic coherence tomography angiography. One patient presented in his left eye a very unusual anatomical variation of macular vascularization. A retinal artery deriving from the inferior temporal retinal artery irrigated the whole macula. The formation of the papillomacular bundle and the temporal raphe nerve fiber layer has been attributed to the earlier development of the central retina and to the existence of 2 distinct watershed zones. However, there are very uncommon anatomical variations of the retinal vasculature in which large retinal vessels cross the raphe and could influence the morphology and structure of the nerve fiber layer of the posterior pole. We review the literature on the subject and document for the first time an anomalous artery that irrigates the whole macula, normal thickness and morphology of the nerve fiber layer, and the temporal raphe.