Retinal arterial and vein occlusion: is surgery ever indicated?

PURPOSE OF REVIEW: To highlight the recent progression in surgical treatments for central retinal vein occlusion (CRVO) and central retinal artery occlusion (CRAO). RECENT FINDINGS: Anti-VEGF treatment, accepted as a primary treatment for CRVO, is unable to effectively treat all types of the diseases. Regarding CRAO, there are not any accepted therapies available. There have however been recent innovations in surgery, such as utilizing robotics-assisted tools in cannulation procedures for central retinal artery occlusion, or micro-cystotomy for refractory macular edema resulting from ischemic CRVO. SUMMARY: Refractory macular edema due to CRVO can be treated with aspiration of the fluid found inside the large cysts often seen in edema. The success rate of micro-cystotomy has been reported at 78% in eyes with refractory macular edema. Recent studies have shown that cannulation with tissue plasminogen activator (tPA) is effective for eyes with CRAO due to thrombus.Recent cannulation or micro-cystotomy procedures can be enhanced with the use of robotic tools which allow us to perform this difficult procedure more easily. Newly developed technology, and consequent developments in surgical procedures, will allow us to deal with unmet needs for retinal vessel occlusive diseases.

Vitrectomy with arteriotomy and neurotomy in retinal artery occlusion - A case series.

Purpose: This study aimed to investigate the visual outcomes and anatomical changes after vitrectomy for retinal artery occlusion. Methods: Twelve patients with retinal artery occlusion (11 central retinal artery occlusion and 1 branch retinal artery occlusion) were part of this study. Our patients were treated with vitrectomy with arteriotomy or with neurotomy and arteriotomy. Complete ophthalmic examination was performed preoperatively, at 2 weeks, and 1, 3, 6, 9, and 12 months after surgery. Results: The mean preoperative best-corrected visual acuity (BCVA) was 1.94 logMAR, and the final BCVA after 12-months follow-up was 2.04 logMAR. After vitrectomy with arteriotomy, the BCVA in patients treated with neurotomy and arteriotomy was 1.65 and 2.45, respectively (P = 0.038). Conclusion: No benefits have been achieved from using vitrectomy in retinal artery occlusion cases.

Novel Acute Retinal Artery Ischemia and Reperfusion Model in Nonhuman Primates.

BACKGROUND AND PURPOSE: The retina, as an externally located neural tissue, offers unique advantages in investigating the effect of therapeutic intervention on the brain. In this study, we put forth a clinically relevant model of retinal ischemia and reperfusion in nonhuman primates. METHODS: Acute retinal artery ischemia and reperfusion was induced by injecting an autologous clot into the ophthalmic artery of adult rhesus monkeys, and recanalization was achieved by focal thrombolysis with tPA (tissue-type plasminogen activator). Digital subtraction angiography and fluorescein angiography were used to evaluate blood flow in the retina and the choroid. Electroretinogram, optical coherence tomography, and hematoxylin and eosin staining were used to evaluate the structure and function of the retina after ischemia. RESULTS: Digital subtraction angiography and fluorescein angiography images confirmed occlusion of the ophthalmic and central retinal arteries, as well as recanalization after tPA thrombolysis. Electroretinogram indicated retinal functional damage following ischemia, and thrombolysis partially rescued its impairment. Optical coherence tomography and hematoxylin and eosin staining revealed ischemia-induced changes in the retina, and tPA partially mitigated these damages. CONCLUSIONS: This novel acute retinal artery ischemia and reperfusion model in rhesus monkeys may closely simulate retinal ischemia/reperfusion in clinical practice and provide an optimal platform for screening neuroprotective strategies.

Effect of vitrectomy with intrasurgical regulation of intraocular pressure in a rabbit model of central retinal artery occlusion.

Central retinal artery occlusion (CRAO) is an ophthalmic emergency that causes severe and permanent visual impairment. The effects of conventional treatments on recanalizing retinal arteries and improving visual outcome are equivocal. This study was designed to determine the possible benefits of pars plana vitrectomy (PPV) with intrasurgical regulation of intraocular pressure using intraocular vascular counterpulsation (IVT). CRAO was induced by 532-nm argon green laser activation of auricular intravenous injected rose bengal, a photosensitive dye, in the central retinal arteries (CRA) of eighty-four New Zealand white albino rabbits. CRAO rabbits were randomly assigned to photocoagulation, vitrectomy and counterpulsation groups. Depending on the time intervals between surgery and CRAO induction, vitrectomy and counterpulsation groups were further divided into 2 h (2h), 6 h (6h) and 24 h (24h) subgroups. The proportion of eyes with complete recanalization was significantly higher in the 2h counterpulsation subgroup after three days (P = 0.032) and in all counterpulsation subgroups after one week (P = 0.020). After one month, the 2h and 6h counterpulsation subgroups showed greater oscillatory potential (OPs) responses (F = 3.519, P = 0.049). The 2h counterpulsation subgroup also exhibited greater b-wave amplitude in photopic 3.0 Flicker(F = 4.530, P = 0.044). Histologic evaluation revealed less destruction in the inner retina for the 2h and 6h counterpulsation subgroups. Expression of HSP70 was higher in the 2h and 6h counterpulsation subgroups (F = 48.915,P < 0.001). Levels of HSP90 were lower in all counterpulsation subgroups (F = 30.065,P < 0.001). Levels of TNF-α were lower in the 2h counterpulsation subgroup (F = 14.762,P < 0.001). These results indicate that PPV with IVT was effective to recanalize retinal arteries after CRAO. Early intervention provided better morphologic and functional prognosis for inner retina. The protective effect was related with higher retinal levels of HSP70 and lower levels of HSP90 and TNF-α.

A cluster of central retinal artery occlusions following cataract surgery.

Purpose: To report a series of central retinal artery occlusions (CRAO) following cataract surgery complicated by posterior capsular rupture (PCR). Methods: Data from 14 patients with acute CRAO following cataract surgery was collected for this study including subject demographics, initial and final best-corrected visual acuity, systemic investigations, optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) findings. Results: Mean subject age was 59.9 ± 12.1 years. Male: Female ratio was 1:1. All patients were operated between October and November 2015 and presented with acute vision loss 1 to 4 days after surgery. All the patients underwent cataract surgery under peribulbar anesthesia and had PCR for which anterior vitrectomy (AV) was done. In all the cases Ethylene oxide (ETO) sterilized vitrectomy probe was used for AV. Clinical picture of CRAO was noted in all the cases during the immediate postoperative period. OCT showed inner retinal layer hyperreflectivity while FFA was normal in all the cases. The final visual acuity was poor in all the eyes. This paper discusses the possible mechanisms of CRAO in these cases. Conclusion: CRAO is a potential complication of peribulbar anesthesia for intraocular surgery in patients with vascular risk factors and hence any substance that can aggravate the vasospasm in such patients should be used cautiously. Vasospasm could be caused by ETO as residual ETO could be present in the vitrectomy machine tubing causing toxicity. It is recommended to be cautious while using ETO sterilized instruments for cataract surgery.

Cilioretinal artery branch avulsion secondary to surgical embolectomy: management and outcome. Case report / Avulsão do ramo da artéria ciliorretiniana secundária à embolectomia cirúrgica: manejo e desfecho. Relato de caso

ABSTRACT We report the trans-operative approach and short-term outcome for a patient who suffered a traumatic avulsion of the cilioretinal artery branch during the surgical management of a cilioretinal arterial branch occlusion with intraocular embolectomy. The patient underwent a pars plana vitrectomy with in situ embolectomy. The blocked artery was incised using 25 Ga vertical scissors, and embolus manipulation was performed using microsurgical forceps. During embolus extraction, the occluded cilioretinal artery and its branch were inadvertently avulsed and torn with subsequent intense bleeding. Laser and endodiathermy were used for acute hemostasis. The maneuvers created an unintended retinochoroidal anastomosis. Visual-field improvement was noted three months after the surgery. In the event of a complicated surgical embolectomy with the avulsion of the artery, the formation of a retinochoroidal anastomosis and reperfusion of the occluded artery may occur along with the improvement of the visual field in some cases.

RESUMO Relatamos a abordagem transoperatória e o desfecho em curto prazo de um paciente que sofreu uma avulsão traumática do ramo da artéria ciliorretiniana durante o tratamento cirúrgico de uma oclusão do ramo arterial ciliorretiniano com embolectomia intraocular. O paciente foi submetido a uma vitrectomia pars plana com embolectomia in situ. A artéria bloqueada foi incisada com uma tesoura vertical de 25 Ga e a manipulação do êmbolo foi feita com pinça microcirúrgica. Durante a extração do êmbolo, a artéria ciliorretiniana ocluída e seu ramo foram inadvertidamente avulsionados e rasgados com sangramento intenso subsequente. Laser e endodiatermia foram utilizados para hemostasia aguda. As manobras criaram uma anastomose retinocoroidiana não intencional. Melhora do campo visual foi observada três meses após a cirurgia. No caso de uma embolectomia cirúrgica complicada com a avulsão da artéria, a formação de uma anastomose retinocoroidiana e reperfusão da artéria ocluída pode ocorrer juntamente com a melhora do campo visual em alguns casos.

Cilioretinal artery branch avulsion secondary to surgical embolectomy: management and outcome. Case report.

We report the trans-operative approach and short-term outcome for a patient who suffered a traumatic avulsion of the cilioretinal artery branch during the surgical management of a cilioretinal arterial branch occlusion with intraocular embolectomy. The patient underwent a pars plana vitrectomy with in situ embolectomy. The blocked artery was incised using 25 Ga vertical scissors, and embolus manipulation was performed using microsurgical forceps. During embolus extraction, the occluded cilioretinal artery and its branch were inadvertently avulsed and torn with subsequent intense bleeding. Laser and endodiathermy were used for acute hemostasis. The maneuvers created an unintended retinochoroidal anastomosis. Visual-field improvement was noted three months after the surgery. In the event of a complicated surgical embolectomy with the avulsion of the artery, the formation of a retinochoroidal anastomosis and reperfusion of the occluded artery may occur along with the improvement of the visual field in some cases.

Branch retinal artery occlusion post-penetrating globe injury with intraocular foreign body.

Intraocular foreign body (IOFB) in cases of penetrating eye injury accounts for an important indication of vitreoretinal intervention following ocular trauma. Vascular occlusion as a complication of IOFB is rare. Here we present a case of a 34-year-old male with post-traumatic cataract and an intraocular metallic foreign body (IOFB) lodged in the superficial layers of the retina inferotemporal to the disc, causing an inferotemporal branch retinal artery occlusion. The case was managed by lensectomy with pars plana vitrectomy and IOFB removal followed by a second procedure of secondary IOL implantation. Final best-corrected visual acuity improved to 6/24. This case highlights an unusual sequelae following penetrating ocular trauma.

Idiopathic Retinal Vasculitis, Aneurysms, and Neuroretinitis Syndrome Presenting With Branch Retinal Artery Occlusion.

Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) is a rare syndrome affecting the retinal and optic disc vasculature. Diffuse retinal ischemia, macular edema, and neovascularization may lead to bilateral vision loss. The authors report a case of a 36-year-old woman presenting with branch retinal artery occlusion (BRAO) in her right eye who was subsequently diagnosed with IRVAN syndrome. She was treated with panretinal photocoagulation for peripheral retinal ischemia and pars plana vitrectomy for vitreous hemorrhage. She later developed a BRAO in her left eye. This case demonstrates that BRAO may be a presenting feature of IRVAN syndrome. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:948-951.].

Treatment of retinal artery occlusion using transluminal Nd:YAG laser: a systematic review and meta-analysis.

AIMS: To review clinical experience, efficacy, and safety of transluminal Nd:YAG laser embolectomy/embolysis (TYE) for retinal artery occlusion. METHODS:  Electronic databases were searched for all published clinical studies and case-reports reporting on TYE in central (CRAO) or branch (BRAO) retinal artery occlusion. Individual patient data was evaluated in a weighted pooled analysis. RESULTS: Sixty-one cases were reported, 47 with BRAO and 14 with CRAO. Visual acuity (VA) at onset averaged 20/252 (1.1 LogMAR) and improved following the procedure to 20/47 (0.37 LogMAR) at first follow-up (avg. 6 days, P < 0.001) and to 20/30 (0.18 LogMAR) at last reported follow-up (avg. 1.1 years, P = 0.02). Patients with worse VA (<20/200) improved further (12 vs. three lines, P < 0.001). VA was not improved when using higher pulse energies (≥ 2.4 mJ) which were associated with more vitrectomies. In a weighted analysis vitreous/sub-retinal hemorrhage was estimated to occur in 54% of cases and required vitrectomy in 18% of cases. CONCLUSIONS: TYE was followed by significant visual improvement in the vast majority of cases, including CRAO, and was frequently associated with vitreous hemorrhage. Patients with poor visual acuity appear to benefit further and higher pulse energies may be detrimental. Lack of randomization and intrinsic biases prevent any definite conclusions regarding the benefits and further research is warranted.

Nd YAG Laser Embolysis in a Young Woman with Hemiretinal Artery Occlusion.

Retinal artery occlusion is an uncommon condition but can lead to grave consequences if not managed in time. Elderly population with other comorbid conditions like hypertension, ischemic heart disease, hyperlipidemia and stroke are commonly affected. However, this condition may affect younger population with entirely different systemic associations. Thromboembolism, which usually takes place secondary to cardiac emboli or hypercoagulable states cause retinal artery occlusion in young population. A24-year lady presented with a short history of unilateral altitudinal visual loss. On examination, she was found to have hemiretinal artery occlusion. Ocular massage, anterior chamber paracentesis was performed initially, followed by Nd YAG laser embolysis, which led to successful restoration of retinal circulation and significant improvement in visual field loss. Detailed evaluation and systemic investigations were carried out to identify the underlying cause, but no systemic association could be found.