Visual acuity assessment of central retinal artery occlusion patients with or without paracentral acute middle maculopathy via OCT-A

Stability of small incision lenticule extraction over laser in situ keratomileusis at an altitude of 3874 m

The purpose of this study was to evaluate the stability of small-incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK) when ascending from near sea level to an altitude of 3874 m. The visual acuity (VA), intraocular pressure (IOP), spherical equivalent refraction (SER) and biometric parameters of 20 normal subjects (40 eyes, controls) and 36 subjects who underwent corneal refractive surgery (35 eyes with SMILE and 36 eyes with LASIK) were examined in Chongqing (C, 500 m above sea level) and 7-10 days after a collective travel to Shigatse (S, 3874 m above sea level). SER and corneal thickness (CT) were choosed as main indicators of the stability of corneal refractive surgery at high altitude. The IOP decreased and CT increased from C to S, while VA and SER did not significantly change in the control subjects. The VA and IOP of both the SMILE and LASIK subjects did not significantly change at an altitude of 3874 m. At high altitudes, no significant difference in the SER was found among the SMILE subjects, while a significant myopic shift was found among the LASIK subjects. With an increase in the altitude of 3874 m in S, an obvious increase in CT was observed in subjects who underwent corneal refraction surgery. The increase in CT in the SMILE group was significantly less than the increase in CT in the LASIK group. In addition, the biometric parameters of the SMILE and LASIK subjects showed the same minor changes as those of the control subjects when exposed to high altitude. The VA, IOP and biometric parameters of the subjects who underwent SMILE and LASIK remained stable at an altitude of 3874 m. SMILE shows better stability than LASIK in the refractive state and CT when exposed to high altitude.Trial registration: This study was approved by the Ethics Committee of The Second Affiliated Hospital of Army Medical University (ID: 2022-No.084-1) and adhered to the principles of the Declaration of Helsinki. The study was registered at http://www.chictr.org.cn (Study NO. ChiCTR2200059833) on 12/5/2022.

The clinical features and perfusion density in paracentral acute middle maculopathy by optical coherence tomography angiography study

PURPOSE

To observe the clinical features of the paracentral acute middle maculopathy (PAMM) and to investigate the changes in perfusion density of superficial capillary plexus (SCP) and deep capillary plexus (DCP) in PAMM by optical coherence tomography angiography (OCTA).

METHODS

Twelve patients (12 eyes) diagnosed with PAMM and 13 healthy participants (13 eyes) were enrolled. The clinical features of 12 PAMM patients were recorded. The perfusion density of SCP and DCP in the parafovea and perifovea (divided into Temporal, Superior, Nasal, and Inferior) was measured by OCTA in PAMM and healthy eyes. Automated macular maps, including SCP and DCP, were also performed.

RESULTS

The mean age of patients was 48.08 (range 14-72) years. The best corrected visual acuity (BCVA) was from finger count (FC) to 1.0. Risk factors included hypertension, diabetes mellitus, COVID-19, etc. The patients had signs of retinal vascular disease except for one patient with isolated PAMM. A spectral-domain OCT image of the PAMM eye showed hyperreflectivity in the inner nuclear layer (INL). Compared with healthy eyes, SCP and DCP in PAMM eyes were significantly reduced in all sectors (all p < 0.05) in the parafovea and perifovea. The average perfusion density of SCP in parafovea and perifovea in PAMM eyes were 46.94±4.34% vs 52.21±3.98 % (p = 0.002), 44.01±3.95% vs 50.51±3.14 (p = 0.000) in healthy eyes. The average perfusion density of DCP in parafovea and perifovea in PAMM eyes were 51.22±4.16% vs 57.15±3.87 % (p = 0.002), 47.375±6.23% vs 54.27±5.33 % (p = 0.002) in healthy eyes.

CONCLUSION

PAMM often accompanies concurrent ocular and systemic diseases. OCTA results confirm that the perfusion density of SCP and DCP in the parafovea and perifovea significantly reduced in PAMM patients.

Distinctive Imaging Characteristics of Retinal and Cerebral Vessels between Central and Branch Retinal Vein Occlusion by MRI and AI-Based Image Analyzer

Retinal vessels have been good predictive and prognostic imaging biomarkers for systemic or eye diseases. Numerous studies have shown that the two retinal vein occlusion entities may correlate with cardiovascular and cerebrovascular events or primary open-angle glaucoma. This study aims to investigate if there is a disparity in the correlations between branch RVO (BRVO) and central RVO (CRVO) with systemic disorders or POAG, thus explaining the pathogenic difference between BRVO and CRVO. This retrospective case-control study enrolled 59 RVO subjects (118 eyes), including 25 CRVO and 34 BRVO subjects, who received routine eye and brain MRI examinations. The geometric characteristics of the caliber of the retinal and cerebral blood vessels and the optic nerve subarachnoid space width (ONSASW) were measured. Multivariable logistic regression analysis showed that ONSASW at 3 mm behind the globe (p = 0.044) and the relative retinal venular calibers (p = 0.031) were independent risk factors for the CRVO-affected eyes group in comparison with the BRVO-affected eyes group after adjusting for age, duration of hypertension, BMI, and IOP. In the CRVO-affected eyes, narrower relative retinal arteriolar calibers (p = 0.041) and wider relative venular calibers (p = 0.011) were independent risk factors compared with the CRVO-contralateral normal eyes when adjusting for IOP. We concluded that BRVO may be more associated with cerebrovascular diseases, and CRVO may be correlated with primary angle glaucoma. The geometric characteristics difference between the retinal and cerebrovascular may explain the pathological difference between CRVO and BRVO.