Efficacy and Safety of Tranexamic Acid (TXA) Used in Reduction of Pathological Blood Flow Present in Eye Disease and Eye Surgery

Abstract

Tranexamic acid (TXA) is an antifibrinolytic commonly used for hemostasis. TXA has been used extensively in medicine, although minimal reviews exist that assess its efficacy and safety in ophthalmologic use. The objective of this systematic review is therefore to effectively summarize the use of TXA within the context of ophthalmology. A literature review was conducted using electronic databases: PubMed Central, Google Scholar, and the University of Manitoba Library Database. Studies were collected through preset participant criteria and outcome measures. Comparisons were made based on derived similarity in goals and methods between studies. Twenty-seven studies in total were identified and used. A majority of studies with traumatic hyphema patients indicate a significant reduction of secondary hemorrhage rates (among the traumatic hyphema cohort studies, a range of 0 to 1.9% compared to 7.1 to 9.6% in control groups). TXA has been shown to significantly reduce central macular thickness in macular edema associated with retinal vein occlusion (8.3% reduction) but not in diabetic macular edema. However, no significant reduction of bleeding was demonstrated in post-vitrectomy patients nor during oculoplastic surgeries. In regards to ocular adverse effects, chromatopsia, central retinal vein occlusion, branch retinal artery occlusion, and ligneous conjunctivitis have been reported. TXA should be used with caution in patients with certain underlying conditions.

1. Introduction

Tranexamic acid (TXA) is an antifibrinolytic agent which has been used in medicine for bleeding control1. TXA inhibits plasmin production, thereby maintaining blood clots and reducing bleeds1. TXA was initially developed and released in 1962 to successfully treat heavy menstrual bleeding and its ability to effectively reduce bleeding has been further established in diverse cases, including various surgeries, parturition, hereditary bleeding disorders, and nosebleeds to name a few1. TXA is found to be 6 to 10 times more potent than its other common antifibrinolytic, epsilon-aminocaproic acid (EACA)2, and patients are less likely to experience the common side effects including nausea and diarrhea2.

A literature search indicates a fair amount of research on the use of TXA and its effects in medicine, although minimal reviews exist that thoroughly assess its efficacy and safety in ophthalmologic use—only its use for traumatic hyphema has extensively been covered3–7. The aim of this review is to report and interpret its historical use in current literature, while further directing its use towards a safer and more accurate use of TXA in ophthalmology. Thus, this review will effectively summarize the use of TXA within the context of ophthalmology firstly, by assessing its efficacy in ocular surgeries as well as treating ocular diseases involving pathological blood flow. Secondly, this review will aim to determine any ocular adverse effects to be cautious of from general TXA use.

Areas where TXA has been used in ophthalmology included traumatic hyphema, macular edema (ME), post-vitrectomy hemorrhage, and hemorrhage during and after oculoplastic surgery. It is also worth mentioning that Remifentanil and hydralazine—a synthetic opioid and a direct vasodilator, respectively—are drugs used for induced hypotension8 to reduce intraoperative blood loss and are considered safe but also more effective than TXA in this setting8. Bleeding control in these eye diseases and surgeries is necessary for the following reasons: Secondary hemorrhage in traumatic hyphema is generally associated with more serious complications than its first hemorrhage7. Macular edema is associated with progressive, irreversible loss of vision as it worsens and various invasive treatment modalities come with their own complication risks as well9. Overall, for eye diseases, pathological fluid flow should be kept within physiological conditions to prevent vision loss. Reduction of intraoperative blood loss is also desirable to reduce surgery time as well as the use of electrical cautery which can lead to scarring10.

In regards to ocular adverse effects, responses that may lead to serious damages to the eye were considered important. Left untreated, these particu