Refractive surgery current status: expanding options

Abstract

Independence from eyeglasses and contact lenses has significant value: ‘The global refractive surgery devices market size was valued at USD 168.2 million in 2020 and is expected to expand at a compound annual growth (CAGR) of 7.7% from 2021 to 2028’ [1]. In addition, ‘Global demand for refractive surgical procedures (laser refractive surgery, presbyopiacorrecting surgery, RLE [Refractive Lens Exchange], and phakic IOL implantation) is expected to grow at a compound annual rate of 9.6% from 2020 to 2025, with annual surgical volume increasing from 3.6 million to 5.8 million procedures’ [2]. Considering the United States alone, it has been reported that ‘The vision correction market generated professional service fees of over $5 billion in 2016 and by 2019 it increased to $6.3 billion mainly provided by independent eye care providers’ [3]. These numbers reflect the high levels of satisfaction achieved with refractive procedures. For example, ‘98.7% of all patients were satisfied or very satisfied after their LASIK surgery’ [4], and ‘99.4% of 1,542 patients surveyed’ stated that they would elect to have the EVO implantable collamer lens (ICL) again [5]. As options for refractive correction have increased, the range of potential surgical candidates has broadened. Today, procedures are available for virtually any type of refractive error, as well as presbyopia. Establishing candidacy for refractive surgery involves assessment of the patient’s motivation and medical condition. The ideal candidate is highly motivated and has a normal visual system apart from refractive error and/or presbyopia. Every incremental decrease in motivation or increase in pertinent findings alters the risk benefit ratio, until the balance swings away from intervention. However, risks related to physical findings may be mitigated by the choice of procedure. Common significant findings that increase surgical risk or impact the choice of procedure include ocular surface disease [6], signs that increase suspicion of corneal ectasia [7], corneal endothelial insufficiency [8], shallow anterior chamber depth or narrow anterior chamber angle [9], incipient or frank cataract [10], signs of ocular inflammation or uveitis [11], glaucoma [12], macular disorders [13], and predisposing lesions that increase the risk of retinal detachment [14]. Age and refractive error primarily determine the choice of procedure, while physical findings play an important secondary role. In addition, patient expectations may influence the decision. For example, knowledge of LASIK is widespread due to its high-profile introduction in the late 1990s [15], extensive marketing by corporate laser vision centers [16] and subsequent controversies regarding untoward outcomes [17]. Because it is commonly equated with refractive surgery, patients may arrive at the doctor’s office expecting to be offered LASIK and unaware that other options exist. All else being equal, it is sometimes easier for a doctor to simply agree with the patient rather than provide education regarding other procedures which may offer advantages. For example, SMILE (Small Incision Lenticule Extraction) corrects myopia and astigmatism in the same range as LASIK but exhibits a lower risk of postoperative dry eye [18]. The EVO ICL corrects myopia in a wider range than LASIK or SMILE, the EVO Toric ICL also corrects astigmatism, and these lenses offers several advantages, including preservation of the cornea [19] and crystalline lens [20], no increase in dry eye syndrome [21], no added complexity in future age-related cataract surgery [22], and removability [23]. These alternatives should be described as part of the informed consent process for any patient who may be considered a candidate. Phakic refractive lenses such as the EVO ICL, traditionally ‘restricted to patients’ [21] who are not ideal candidates for laser vision correction [24], are now moving to the forefront of refractive surgery options. Global adoption of the EVO ICL has grown significantly over the last decade [25], and recent FDA approval has set the stage for even greater expansion [26]. Improved safety, effectiveness across a broad range of refractive error and greater patient convenience thanks to the central port design make EVO an attractive option [5]. We have even seen the emergence of refractive surgery clinics devoted solely to EVO implantation. As one author notes, ‘I have been successfully offering the EVO Visian ICL to my patients for more than 4 years, and despite fierce competition from colleagues who offer laser vision correction procedures, I have found that my surgical volume continues to grow steadily year after year’ [27]. The US FDA clinical investigation of the EVO ICL ‘definitively demonstrated the safety and effectiveness of EVO/EVO+ Sphere and Toric ICL lenses for the correction of myopia and myopia with astigmatism’ [28]. In this clinical trial enrolling 629 eyes of 327 subjects, 87.6% of eyes had postoperative uncorrected visual acuity 20/20 or better. 90.5% of eyes were within 0.50 D and 98.9% were within 1.00 D of target. A total of 98.5% of eyes had postoperative corrected visual acuity equal to or better than preoperative corrected visual acuity.