VISION AND EYE Secondary Glaucoma After Blunt Ocular Trauma

Introduction: Ocular trauma is an important cause of unilateral visual impairment and blindness. Among several agents of ocular trauma, blunt trauma is the most common and can lead to secondary glaucoma. Secondary glaucoma due to blunt ocular trauma can be unnoticed and undetected until the formation of glaucomatous optic neuropathy (GON) occurs. This case might not be neglected. Delay in treatment can lead to the progression of GON. Case Presentation: A 68-year-old woman presented to the outpatient clinic in Undaan Eye Hospital complaining of decreased vision and pain in the left eye after blunt trauma to the eye. Her left eye vision was limited to detecting hand motions (1/300) and the intraocular pressure (IOP) was 37.8 mmHg. On the slit lamp biomicroscopic examination, the left pupil was mid-dilated, lens opacification and phacodenesis were detected. The cup-to-disc ratio (CDR) of the left eye increased (0.8-0.9) through the funduscopic examination. Secondary glaucoma due to subluxated lens was diagnosed for the left eye. The patient was given topical and oral antiglaucoma medications and was evaluated after one week of drug use. Since the IOP remained elevated after medical therapy, left eye trabeculectomy was conducted. Bleb was formed postoperatively and the IOP was getting normal without oral glaucoma medications. Conclusion: Blunt ocular trauma can lead to secondary glaucoma. Thorough examinations and immediate treatments should be conducted to preserve patient’s vision and prevent further optic nerve damage.


Introduction
Ocular trauma is a significant cause of avoidable monocular vision loss. [1], [2] Fifty-five million cases of ocular trauma are estimated to occur annually, and 34% of the cases lead to vision loss or blindness. [3] The extensive socioeconomic burden may follow the incidence of ocular trauma; however, it is often neglected. [4] Several studies reported that blunt ocular trauma predominates the mechanism of ocular trauma. [2], [4], [5], [6] It is responsible for approximately 40% of eye injuries. [7] It may lead to vision-threatening problems, such as traumatic glaucoma. Traumatic glaucoma has become a concern as glaucoma alone is the most common cause of irreversible blindness worldwide. [7], [8] Studies have mentioned [7], [9] the prevalence of traumatic glaucoma after blunt ocular trauma to be around 11% in India and trauma was the most common cause of secondary glaucoma in China (28%).
The development of glaucoma induced by the elevation of intraocular pressure (IOP) as a result of the injury by blunt objects occurs through the damage of each part of the eye including cornea, sclera, anterior chamber, trabecular meshwork, lens, vitreous, choroid, and the orbit. [10] This study reports a case of secondary glaucoma due to a subluxated lens following blunt ocular trauma. In this case, the patient had only used a topical antiglaucoma agent for two months before she got referred. The delay in surgical and referral management of the patient seemed to take effect in the long-term increase of IOP that led to the continuous development of glaucoma. Due to this reason, filtering surgery was conducted before considering the extraction of the  Clinical findings on the left eye's anterior segment evaluation were mid-dilated pupil, lens opacification, and phacodonesis ( Figure 1). On the funduscopic examination, the CDR of the left eye was between 0.8-0.9. Gonioscopic evaluation was not done due to the mid-dilated pupil.

Case presentation
Based on these findings, the patient was diagnosed with corneal leucoma and senile cataract of the right eye and secondary glaucoma due to subluxated lens of the left eye.
We treated her with topical and oral medications and planned to evaluate her after a week of drug use.

Discussion and conclusions
The case described the development of secondary glaucoma due to a subluxated lens following blunt ocular trauma. Some traumatic glaucoma cases might be left unnoticed and undetected until the development of glaucomatous optic neuropathy occurred. [7] Although this case was not completely neglected, as the patient got treated after the injury took place, adequate treatments seemed to be lacking.
The patient was administered antiglaucoma medication using a topical beta-blocker after the injury. with blunt trauma. [11], [12] A study reported that the major cause of lens dislocation was trauma. [12] Blunt trauma causes compression of the eye antero-posteriorly which then cause an expansion of the eye in several directions, laterally, superiorly, and inferiorly. It also leads to stretch and tear of the lens zonules which then results to partial or complete lens dislocation. [10], [11], [13] Elevated IOP following lens subluxation may result from pupillary block. [10], [14] The symptoms of secondary glaucoma following lens subluxation are blurred vision and pain in the eye [12] , which are in accordance with our patient. Slit lamp biomicroscopic examination may reveal the mobility of the lens (phacodonesis) [10], [12] , which is also detected in our patient's eye. The increase of CDR also indicated the formation of glaucomatous optic neuropathy. [15] Treatment of glaucoma is still focussing on lowering the IOP thus far. Initial antiglaucoma medications are to be prescribed for patients with glaucoma. Failure to control IOP after maximum tolerated medications lead to further surgical intervention, such as trabeculectomy. [14], [15], [6] Trabeculectomy is an incisional procedure to create a bypass for the aqueous humor outflow. It is created by making a passage/fistula between the anterior chamber and the subconjunctival space. [15] Antimetabolite is used to prevent scar formation to keep the patency of the filtering bleb, hence reducing trabeculectomy failure. [16] In this case, mitomycin C (MMC) was applied.
Lens extraction is a primary consideration in the case of lens subluxation following blunt ocular trauma.
However, in this case, filtering surgery was elected before performing lens extraction due to the long-term increase of IOP as a rise in IOP is associated with functional loss in the visual field and reduction in retinal nerve fiber layer thickness. [17] Our patient was successfully treated with trabeculectomy after previous failure to control the IOP using anti-glaucoma medications. It is in line with a study which carried out surgical intervention after failure to control IOP using antiglaucoma medications for two weeks. [6], [18] Avoiding surgical intervention in an uncontrolled IOP condition may lead to permanent vision loss and total blindness. [