Cataract is one of the leading causes of preventable blindness worldwide and represents a major cause of low vision in developed and developing countries. Fortunately, cataract surgery is one of the most successful procedures in ophthalmology. However, challenges remain that require the proactive mitigation of risk. A number of steps can achieve this goal including recognition of the associated risk factors using advanced diagnostic technology, improved measurements and newer formulas for accurate IOL calculation and refined surgical techniques that minimize complications. The combined effect of these steps will contribute to greater postoperative accuracy of the intended refractive outcome and greater patient (and surgeon) satisfaction.
This issue presents diverse topics encompassing the management and challenges related to cataract surgery. For example, Courtright’s1 comprehensive article covers the prevalence, intervention, limited opportunities and challenges in the management of childhood cataract in sub-Saharan Africa. Whereas Baheti et al.2 present the medical and surgical challenges of uveitic cataract. Baheti et al.2 emphasize the importance of immunomodulation therapy to control preoperative and postoperative intraocular inflammation and strategies to avoid complications.
Progress in improving the outcomes of cataract surgery has been partially due to accurate measurements from contact or immersion ultrasound, optical biometry and more recently, optical coherence tomography (OCT).3–9 The accurate measurement leads to better selection of the intraocular lens (IOL) from the myriad formulas currently available.3–9 Despite advances in measuring axial length and keratometry readings, estimating the effective lens power by determining the anterior chamber depth and lens thickness with new IOL formulas, refractive surprise of 1 D or greater can occur in a small subset of patients even with the use of third generation IOL formulas.3 Recently published studies have found that incorporating postoperative data from the first eye helps determine the effective lens (IOL) position and leads to greater accuracy of IOL calculations for the fellow eye.4–6 This process involves optical biometry measurement to determine the effective lens position postoperatively, in addition to a current postoperative manifest refraction. The greater accuracy for the fellow eye is one of the advantages of waiting 3–4 weeks postoperatively before IOL implantation in the second eye. Clinically this will be most beneficial in difficult cases such as eyes with extreme axial length and keratometry, high astigmatism and eyes that have undergone previous corneal refractive or transplantation surgery.
The most current OCT units enable precise estimation of corneal power, in addition to other cases that have corneal laser vision correction for myopia and hyperopia.9 In this issue, original and review articles addressing IOL calculations with newer and standard technology have been cogently covered by Haigis,7 Wilson8 and Tang9 Additionally, Grewal and Grewal10 present an insightful review of the clinical applications of Scheimpflug Imaging technology – corneal topography, pachymetry and corneal elevation data – for cataract surgery.
Included in this issue are articles on mitigating surgical and postoperative complications and clinical pearls in detecting cataracts. As Mohammadpour et al.11 point out, performing an excellent capsulorhexis is an important factor in reducing complications and ensuring good IOL position for better refractive and optical outcomes. Kalantan12 presents a thorough review of recognizing the relatively uncommon posterior polar cataract and the various treatment options. Vasavada et al.13 share their experience and techniques in reducing complications during phacoemulsification for posterior polar cataract cases.
Masket et al.14 discuss possible late postoperative complications and the management of dislocated posterior chamber IOLs in patients with retinitis pigmentosa. There is a relative paucity of data on the incidence of hereditary diseases in Saudi Arabia and neighboring countries. Khan describes his personal experience regarding the genetic causes of inherited pediatric cataract in this region.15
The recent introduction of femtosecond (FS) assisted cataract surgery has garnered much attention. Currently there are at least three femtosecond lasers with total or partial FDA approval for use in cataract surgery. Femtosecond laser assisted cataract surgery has provided ophthalmologists with an exciting tool that may increase safety and further improve outcomes. However incorporation into clinical practice may be slow due to the financial burden of FS technology for the eye care givers and patients. Hodge et al.16 present a comprehensive review of the current literature on FS technology for cataract surgery and report their initial experience on 700 cases performed by eight surgeons with the LenSx femtosecond laser (Alcon Inc., Fort Worth, TX, USA). Their16 results are promising including a decreased rate of complications; however, the effect on the corneal endothelium needs further short and long term study. Although FS assisted cataract surgery is promising, patients with small pupils, subluxated lenses, small palpebral fissures, and the technical demand and the increased length of time for the whole procedure represent some limitations of the current technology. Hodge et al.16 conclude that FS assisted cataract surgery will reduce complications, improve safety and outcomes. As cataract and lens surgery is a broad field and a very common procedure, other related topics need to be addressed in future issues.
References
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