Inherited retinal degeneration (IRD) is a group of fundus diseases characterized by a high degree of genetic heterogeneity and clinical heterogeneity, and more than 300 genetic mutations have been identified in association with IRD. Dysregulation of the intracellular second messenger cyclic guanosine monophosphate (cGMP) plays an important role in the development of IRD. cGMP participates in phototransduction process in photoreceptors. Abnormally elevated cGMP over-activate protein kinase G and cyclic nucleotide-gated channel, causing protein phosphorylation and Ca2+ overload, respectively, and these two cGMP-dependent pathways may individually or collectively drive photoreceptor degenerative lesions and death; therefore, reducing cGMP synthesis and blocking downstream signaling can be considered as treatment strategies. Investigating the molecular mechanisms of cGMP dysregulation in photoreceptor degeneration may provide a more comprehensive picture of the pathogenesis of IRD, as well as ideas for finding new therapeutic targets and designing therapeutic programs.
ObjectiveTo observe the clinical and imaging features of patients with retinal vein occlusion (RVO) complicated with retinal artery occlusion (RAO). MethodsA retrospective clinical study. Fifteen patients with 15 eyes with RVO combined with RAO and macular edema diagnosed by ophthalmology examination in the Department of Ophthalmology, First People's Hospital of Xianyang City during 2 years from February 1, 2022 to January 31, 2024 were included in the study. Branch retinal vein occlusion (BRVO) combined with branch retinal artery occlusion (BRAO) occurred in 3 cases and 3 eyes. Central retinal vein occlusion (CRVO) complicated with central retinal artery occlusion (CRAO) in 12 eyes. Best corrected visual acuity (BCVA), intraocular pressure, scanning laser ophthalmoscope, optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and serum homocysteine were all performed. OCT angiography (OCTA) was performed in 6 eyes. All eyes were treated with intravitreal injection of anti-vascular endothelial growth factor drugs. After the initial 1 treatment, dosage was assessed as needed. Follow-up was performed every month for 12 months after treatment. FFA inspection was performed at 3 months. During follow-up, it was found that there were no perfusion areas of capillaries, and retinal laser photocoagulation therapy was given in time. Fundus manifestations, FFA, OCT, OCTA characteristics and causes of disease were analyzed retrospectively. ResultsThere were 15 eyes in 15 cases, 9 eyes in 9 males; 6 women with 6 eyes. Age was (61.0±9.7) years. All complained of painless vision loss in one eye. All eyes were positive for relative afferent pupillary disorder. Contralateral congenital optic disc defect was in 1 case; hypertension was in 6 cases; hyperhomocysteinemia was in 2 cases; cerebral infarction was in 3 cases; coronary heart disease was in 1 case. CRVO combined with CRAO was in 12 eyes BCVA light sensitivity-0.25. The BCVA of BRVO combined with BRAO were 0.1, 0.4 and 0.25, respectively. All the patients had retinal edema in the posterior pole of the eye, venous sinuous, dilated, thin arteries and stiff shape. The retina presents with flaky or flame-like bleeding. Posterior polar retinal lint patch was in 13 eyes. In 12 eyes with CRVO combined with CRAO, optic disc edema was observed and the boundary was not clear. In 3 eyes with BRVO combined with BRAO, no obvious abnormality was found in the optic disc, and the boundary was clear. FFA examination showed no or prolonged arterial filling, delayed retinal vein laminar flow, relatively slow or even no capillary filling, macular arteriole atretosis to varying degrees, arch ring structure destruction, optic disc telangiectasia and fluorescein leakage. OCT examination showed that the middle and inner layers of the retina were thickened to varying degrees, the diffuse reflex was enhanced, the interlayer structure was unclear, and the reflex of the lower retinal tissue was weakened. The blood flow density of superficial capillary plexus and deep capillary plexus (DCP) decreased in 6 eyes undergoing OCTA examination. Decreased or interrupted blood flow in the vascular bed of DCP. During the follow-up period, there were 13 eyes with no perfusion area of retinal capillary. The time of occurrence was (1.14±0.95) (0-2) months, and the area was 10-75 disc area. Optic nerve atrophy occurred in 5 eyes. At the last follow-up, visual acuity increased, unchanged and decreased in 12, 2 and 1 eyes, respectively. ConclusionsThe pathogenesis of RVO-RAO is complicated. Most RVO and RAO occurred simultaneously, and a few RVO occurred several days after RAO. Although the RAO manifestations are not typical, the radiographic features are both RVO and RAO. Compared with BVRO combined with BRAO, the prognosis of visual acuity in CRAO patients with CRVO is worse.