1. Central Retinal Vein Occlusion Secondary to Cataract Surgery Austin Bach, DO, MPH, Capritta Roberts, BHS, Benjamin P. Rice, DO, Joel W. Nelson, DO, Alexander Spratt, MD, FRCOphth, Anand Rajani, DO, Roberto Beraja, MD
Introduction:
A central retinal vein occlusion (CRVO) occurs when blood cannot exit the retinal circulation via the central retinal vein. This causes a build up of deoxygenated blood throughout the retina with potentially blinding consequences. There are a number of medical conditions and aspects of a patient’s medical history that predispose to occlusion of the central retinal vein. There have yet to be any studies showing any correlation between CRVOs and intraocular surgical procedures.
Case Presentation:
An 85-year old male presents complaining of feeling “off balance” after cataract surgery in the left eye (OS).  The patient has a history of diabetes, hypertension, hyperlipidemia, and urinary retention, and is taking atorvastatin, clopidogrel, furosemide, ibuprofen, and metformin. Ocular history includes a known 3+ cataract in his right eye (OD), non-proliferative diabetic retinopathy in both eyes (OU) and ocular hypertension OU.
Best corrected distance visual acuities were OD 20/50 and OS 20/40.  Intraocular pressures were 26/23 mmHg, measured by Goldman applanation tonometry.  Pupils reacted normally with no relative afferent pupillary defect. Confrontation visual fields and ocular motility were normal. Slit lamp biomicroscopy revealed a patent peripheral iridotomy in the right eye and fundal examination revealed mild background diabetic retinopathy OU and healthy optic nerves with a cup to disc ratio of 0.2 OU. The patient had central corneal thicknesses of 607μm in his right eye and 582 μm in his left eye. OCT of the nerve was not able to be performed due to the density of the cataract and the visual field was globally depressed, likely due to the cataract. The patient was scheduled for right eye cataract surgery and underwent uncomplicated phacoemulsification with in the bag IOL implantation.
The patient attended for his first scheduled post-operative examination five days after his surgery. He was using 1% prednisolone acetate eye drops every six hours in his operated eye.  Examination of his operated eye revealed a best corrected distance visual acuity of ‘count fingers’ at five feet, an intraocular pressure of 16mmHg, normally reacting pupils with no relative afferent pupillary defect.  Further examination of his operated eye revealed significant corneal edema and anterior chamber flare preventing a fundal view.  Four milligrams in 0.1 milliliter of triamcinolone was injected into Sub-Tenon’s space in his right eye along with instructions to use 1% prednisolone acetate eye drops every six hours and ketorolac eye drops four times a day in his operated eye pending follow-up one week later.
At subsequent follow-up on day 24, after corneal edema had decreased, best corrected distance visual acuity in the operated eye remained ‘count fingers’ at five feet with intraocular pressures of 18 mmHg In both eyes. Dilated fundus examination of the operated eye revealed optic disc margin hemorrhage, dilated veins and retinal blot hemorrhages and flame hemorrhages in all 4 quadrants of the retina.  Further examination of the affected eye, with optical coherence tomography (OCT) of the retina, revealed intraretinal and subretinal fluid in the macula along with a mild epiretinal membrane (figure 1).  Fluorescein angiography revealed venous tortuosity, delayed venous filling and masking by of the choroidal circulation by overlying retinal hemorrhages suggestive of central retinal vein occlusion (figure 2).  In view of the the macula edema the patient was treated with intravitreal injections of bevacizumab 1.25mcg in 0.05ml, monthly for three months with resulting resolution of fluid on OCT examination and improvement of his best corrected distance visual acuity to OD 20/40.
Discussion: A central retinal vein occlusion is diagnosed by the classic funduscopic appearance of tortuous, dilated retinal veins, a swollen optic disc, intraretinal hemorrhages (dot blot and/or flame), and retinal edema. The underlying cause for a CRVO is thought to be occlusion of the central retinal vein near the lamina cribrosa. The Eye Disease Case-Control Study Group found that CRVOs have a strong association with systemic arterial hypertension, diabetes mellitus, and open angle glaucoma.1
There are, currently, no published case reports of patients having a CRVO after a cataract surgery. There is one abstract that reports three cases of elderly patients (72-92 years old) having retinal vein occlusions after no intraoperative complications for phacoemulsification and IOL implantation.2 Our patient had multiple vasculopathic risk factors as did the patients in the aforementioned abstract such as diabetes with a history of non-proliferative diabetic retinopathy, hyperlipidemia, and hypertension.
Our patient had a unique characteristic, which we would like to postulate to be the main cause of his CRVO. He has a history of slightly elevated pressures, his average pressures are from
We postulate that this patient’s combination of vasculopathic risk factors, ocular hypertension and rapid fluctuation of intraocular pressure, as high as 77mmHg, which we have calculated based on the maximum bottle height of balanced salt solution of 105cm, during cataract surgery may have caused him to have a CRVO. Studies are needed to determine if at risk patients can be identified pre-operatively and if surgical techniques can be altered to reduce the occurrence of this sight threatening event.
Conclusion: This is a unique case of a patient having a CRVO immediately after, or possibly during, a cataract surgery. Our patient has many predisposing vasculopathic risk factors and had his central retinal vein occluded, possibly, from the rapid changes in pressure during the cataract surgery. More studies need to be performed, both prospectively, as well as retrospectively, to see if we can find patients who are more likely to get vascular occlusions and to find a surgical technique which can decrease this likelihood.
1. Risk factors for central retinal vein occlusion. The Eye Disease Case-Control Study Group. Arch Ophthalmol ; 114(5):
2. Ting, DSJ, Hegde, V. "Cataract surgery and retinal vein occlusion: Is there an association?" Acta Ophthalmologica. Aug 2013; 91(s252).