Traumatic Cataract: A Review

Purpose: Cataract formation is common following ocular trauma and is a major cause of vision loss worldwide. The purpose of this review article is to discuss the current approaches to treatment of traumatic cataracts. Methods: Review of the recent literature regarding traumatic cataract was performed. Results: The mechanisms behind cataract formation, as well as surgical indications, surgical planning and approach in the acute setting are discussed. Conclusions: Uniformity in the classification and reporting of surgical results is needed to provide better care to patients with traumatic cataracts. Citation: Jacobs EJ, Tannen BL. Traumatic Cataract: A Review. J Ocular Biol. 2016;4(1): 4. J Ocular Biol 3(2): 4 (2016) Page 02 ISSN: 2334-2838 [1]. Another benefit of primary removal is earlier direct visualization of the posterior segment and optic nerve. In these settings, primary cataract removal combined as necessary with limited anterior vitrectomy may be preferred. Whether to also place an IOL during primary cataract removal is subject to debate, but favorable outcomes have been shown in several small case series where primary cataract removal with IOL placement was performed [4]. Considerations in Children Children account for approximately one third of serious eye injuries [7,17]. In pediatric patients, consideration must be given to the timing of clearing the visual axis to prevent stimulus deprivation amblyopia, especially in children less than 5 years old. Cataract surgery should be performed within one year of the ocular trauma, as the risk of amblyopia can significantly increase with longer delay [18]. In addition, in pediatric eyes, a swollen cataractous lens can lead to pupillary block, which further supports prompt extraction to prevent phacomorphic glaucoma. Primary cataract removal, therefore, with or without IOL placement, may be more of a consideration in these cases [19]. Posterior capsule opacification (PCO), however, develops faster in eyes with traumatic cataract. Primary posterior capsulectomy and vitrectomy should therefore be considered for children having traumatic cataract surgery [20]. Other common complications include high positive pressure during surgery and fibrinous uveitis [21]. Epilenticular IOL implantation is one option that can help avoid these common complications, and studies have obtained clear visual pathways and improved visual acuity using this technique [21]. Of note, the use of contact lenses for unilateral aphakia is not an option for children in many parts of the world due to cost, inadequate sanitation and lack of availability. One study of children in sub-Saharan Africa supports the use of posterior chamber IOLs as the standard of care in all children older than the age of two, as this produces the best visual acuity results [22]. The same study reported that IOLs placed in the capsular bag were significantly less likely to require capsulotomy in the future, further decreasing the risk of amblyopia from the development of PCO. In cases from India where the posterior segment was not involved, it was shown that, following extracapsular CE with PCIOL implantation, visual acuity in children was better following blunt trauma versus penetrating trauma [23]. Of course, the presence of a non-congenital cataract in a child with a vague history of trauma should also raise the suspicion of possible child abuse. Surgical Planning and Ancillary Testing Cataract surgery for traumatic cataracts is frequently more complex than standard cataract surgery. This is due to associated damage to the lens capsule and zonules, the presence of synechiae and reduced media clarity leading to the increased risk of intraoperative lens dislocation, capsular rupture and vitreous loss. Thorough preoperative assessment and planning is key to achieving successful surgical outcomes. In the acute setting, where significant corneal and other media opacities obscure visualization, CT imaging may be helpful in initially suggesting the presence of a traumatic cataract [19,24]. Anterior and posterior lens capsular tears can occur simultaneously or separately [25]. Traditional B scan ultrasound is helpful in identifying a broad range of ocular pathology, but lacks the resolution to image the integrity of the posterior capsule or zonular structures [26]. Alternatively, ultrasound echography using a 20-MHz frequency is an effective imaging modality for detection of occult posterior lens capsular rupture [26,27]. Ultrasound biomicroscopy is an effective method for identifying occult zonular damage in patients with anterior segment trauma [28], and may also be helpful in identifying small occult posterior capsular ruptures [29]. More recently, anterior segment OCT and Scheimpflug imaging [30,31] have been useful in determining the presence and extent of posterior capsular rupture and zonular integrity. These modalities, when available, have the advantage over ultrasound modalities of being noncontact. The disadvantage, however, is that they are limited by optical clarity that is often compromised after ocular trauma. Scheimpflug imaging has also demonstrated utility in localizing intraocular foreign bodies [32].