Recent developments in cataract surgery

Abstract

Recent developments in cataract surgeryAs guest editor of this special series of the Annals of Translational Medicine (ATM), I would like to share with the readers at large the contributions from invited authors who provided their unique and expert perspectives on the important and critical topics of this focus series titled "Recent Developments in Cataract Surgery".Cataract surgery is the most common surgical procedure performed in medicine.Over 20 million surgeries were carried out worldwide in the 2015, including 3.6 million in the United States of America and 4.2 million in the European Union (1).The technology progress enabled cataract surgery to become the safest and most predictable eye surgery.However, the increase in life expectancy and quality of life result in rise expectations regarding the outcomes.Presently, individuals over 70 years of age still wish to maintain an active lifestyle, including driving a car and often performing sports.Cataract surgery is no longer a procedure to eliminate the obstacle in vision providing some restoration of vision.It became a refractive procedure to eliminate all refractive errors, including astigmatism, but also in many cases managing co-existing presbyopia.Thus, this is a field of many new ideas and new developments.We still can be better and there is a demand for techniques that are even more perfect.Longer life span brings some new encounters, including more surgeries performed on patients with dementia and other comorbidities related with ageing, including glaucoma and retinal disorders.Moreover, the anticipated duration of intraocular lens (IOL) in the eye has significantly increased, thus physicochemical properties and IOL endurance should allow the IOL to keep its optical properties for up to three decades.Congenital cataract is the leading cause of preventable blindness in children (2).Early surgical intervention may prevent deprivation amblyopia and result in good visual prognosis (3).Optimal surgical management includes microincision cataract aspiration combined with posterior capsulotomy, anterior vitrectomy and primary intraocular lens (IOL) implantation (4).Primary IOL implantation is usually performed in children older than 2 years of age.IOL implantation in children younger than 2 years of age remains a matter of controversy (5).The review by Bremond-Gignac and colleagues discusses recent developments in the diagnosis and management of congenital cataract.It is well known that postoperative intraocular inflammation is usually more severe in younger children and it might be explained by an immature blood-ocular barrier and an underdeveloped immunosuppressive microenvironment or anterior chamber associated immune deviation (6,7).Proper understanding of these mechanisms is pivotal for optimal management of inflammatory response to surgical stimuli (8,9).Postoperative complications arising from intense inflammation include formation of posterior synechiae, posterior capsule opacifications, and fibrous pupillary membrane.This, reinforced antiinflammatory medication has become the mainstay of pediatric cataract surgery (10).The study by Lai et al. presents developmental characteristics of the cytokine profile in aqueous humor and its relationship with the inflammatory response in children.The crystalline lens in humans is characterized by life-long growth and regenerative potential what is derived from the its embryonic origin, the epidermis ectoderm, known for the ability to regenerate after injury (11).Lens epithelial cells (LEC) can proliferate and differentiate to achieve certain extent of lens regeneration, what is regulated by a variety of molecular signals and their interactions.It can be hypothesized that modifying the molecular environment can accelerate and improve the optical quality of lens regeneration.Thus, lens regeneration might be a potential option for visual function restoration after cataract surgery (12).It was argued that integrity of lens capsule, LECs and stem cells are prerequisites for functional in situ regeneration.Thus, a novel surgical strategy, minimally invasive lens-content removal surgery, was introduced (13).It included the 1-1.5 mm capsulorhexis opening located in the periphery of the anterior capsule of the lens (13).The review by Liu et al. provides an extensive update on lens regeneration in humans.Age-related macular degeneration (AMD) is a leading cause of visual impairment in developed countries and a common ocular comorbidity in patients undergoing cataract surgery (14).Although AMD is related with inferior outcomes concerning visual acuity and patient satisfaction (15,16), it generally accepted that patients with AMD benefit from cataract surgery in terms of VA and vision-related quality of life (17).The study by Taipale et al. reports effects of cataract surgery on quality of life for patients with severe vision impairment due to AMD.Moreover, intraocular magnifying devices recently developed can further increase the quality of vision in this group of patients (18).Implantable Miniature Telescope is the only approved surgical device in the US and can provide central Editorial on Recent Developments in Cataract Surgery