Surgical outcomes of laser in situ keratomileusis (LASIK) in patients with stable systemic disease

Laser-assisted in situ keratomileusis (LASIK) surgery has become an established and safe treatment for refractive errors over the past few decades [1]. However, certain systemic diseases, such as autoimmune or connective tissue diseases, are still considered as contraindications for LASIK. The United States Food and Drug Administration (FDA) and the American Academy of Ophthalmology (AAO) have established lists of contraindications, but these recommendations are largely based on limited evidence [2]. The presence of systemic diseases such as rheumatoid arthritis, systemic lupus erythematosus, Sjögren’s syndrome, or inflammatory bowel disease is considered as a relative contraindication, and therefore, patients with stable and asymptomatic conditions are still frequently excluded from LASIK surgery [3, 4]. However, studies on these challenging patient populations have shown the promising results with good refractive outcomes and high patient satisfaction [5]. Nevertheless, some research groups still advise against LASIK treatment for patients with active autoimmune diseases due to concerns about altered tissue response, slower wound healing, and increased risk of corneal complications [4, 6]. The evidence regarding contraindications for LASIK treatment is still insufficient and often relies on subjective expert opinions or limited case reports [7, 8].

In this study, we aim to investigate the safety, efficacy, and predictability of refractive outcomes after LASIK surgery in patients with controlled systemic diseases. The goal is to provide valuable insights that can facilitate therapy decisions and surgical planning for these controversial patient groups by contributing to the limited literature on this topic.

In this retrospective study, we included data from 1936 eyes of 976 patients with stable systemic diseases who underwent LASIK surgery between January 2016 and June 2019. We defined nine different study arms including a control group, which consisted of 1951 patients and 3871 eyes and underwent also LASIK treatment during the same period. All eyes were matched based on age, gender, preoperative sphere and cylinder, treatment type, and eye side. All treatments were performed at private practices of “Care Vision Hamburg,” Germany, and in collaboration with the Ophthalmology Department of the Hospital Medical Center in Hamburg. All patient data were pseudonymized, and written consent was obtained from all patients before surgery. The study was conducted in compliance with the guidelines outlined in the Declaration of Helsinki approved from the local ethics committee (ID: 2021-1278). Additionally, the study was registered in the “German Clinical Trials Register” (trial number ID: DRKS00030317).

The inclusion criteria included that patients should be at least 18 years old, have had refractive stability for a minimum of one year, had a refractive error of at least 1.5 diopters (D), and did not have any ocular diseases affecting vision, keratoconus, pregnancy, lactation, or prior refractive surgical intervention. Additionally, patients with uncontrolled diabetes mellitus, untreated rheumatoid arthritis, active eye inflammation, or multiple systemic diseases were excluded from the study to avoid any bias in evaluation.

After obtaining a comprehensive patient history, which included medication history, all patients underwent a standardized ophthalmological examination to assess the risk of potential intra- and postoperative complications and determine any contraindications. The patients were asked about autoimmune and systemic diseases, medication, and current disease activity. All patients included in our study were in stable condition and under proper medical control of their respective diseases at the time of LASIK treatment. The ophthalmological examination included assessment of the anterior and posterior eye segments, intraocular pressure measurement, corneal pachymetry, and pupillometry. In addition, corneal topography and optical coherence tomography were performed. The preoperative refractive values, including subjective and cycloplegic spherical equivalent and corrected and uncorrected distance, intermediate, and near visual acuity were documented.

All treatments were performed under topical anesthesia following a standard protocol. First, the eye axis is marked in a sitting position. After the patient’s positioning on the laser platform and the disinfection procedure, a microkeratome is used to create a corneal flap, which is then lifted to expose the stroma for excimer laser ablation. Finally, the flap is repositioned to complete the procedure. Postoperative examinations were conducted one day, one week, one month, and three months after surgery. Patients were also instructed to use antibiotic and steroid eye drops for one week postoperatively following a standardized eye drop plan. After the first week, antibiotic and steroid eye drops were stopped, and patients were instructed to use preservative-free artificial tears for at least four weeks.

Safety of the surgery was evaluated as the percentage of eyes that lost two or more Snellen lines postoperatively, and efficacy was defined as the percentage of eyes with a visual acuity of 20/20 or better after surgery. Predictability refers to the percentage of eyes whose postoperative refraction is within ± 0.5 or ± 1 D of the target refraction. The efficacy index (EI) describes the ratio of postoperative uncorrected distance visual acuity (UDVA) to preoperative corrected distance visual acuity (CDVA), while the safety index (SI) describes the ratio of postoperative CDVA to preoperative CDVA. High values of EI and SI indicate better outcomes, with a cutoff of 0.8 for EI indicating a successful surgical outcome.

Statistical analysis was performed using R team software and statistical differences between groups were considered significant at p < 0.05. Normality was checked before t-tests were conducted. For independent groups, the unpaired Student’s t-test was used, while for paired groups, the paired Student’s t-test was used. The Fisher exact test was used to compare percentages. The odds ratio was used to measure the association between two variables and the Mann–Whitney rank test was used when the normality assumption was not met. Finally, retreatments were evaluated using Kaplan–Meier curves and the log-rank test.

In this study, we analyzed eight different patient groups, evaluating their efficacy, safety, predictability, and retreatment rates, and compared each of these outcomes with those of the control group.

The present study represents the first attempt to evaluate the refractive outcome of LASIK surgery in a large number of eyes with various systemic diseases. The data from our study showed a high safety of LASIK in patients with a history of systemic disease, including patients with IBD, diabetes, psoriasis, and rheumatologic diseases, such as Bechterew’s disease (ankylosing spondylitis). The safety results in patients with Bechterew’s disease were good and comparable to those of the healthy control group. However, caution is required in interpreting these results as the number of patients in this group was small. The safety outcomes in our rheumatics group were comparable to those reported by Cobo-Soriano et al. [3], with no loss of more than one Snellen line postoperatively.

The study found that the efficacy of LASIK In patients with IBD, diabetes, and psoriasis was comparable to other studies [3, 6]. All patients with ankylosing spondylitis achieved a 20/20 postoperative UDVA, while those taking antidepressants and with hay fever had a lower success rate potentially because of dry eye symptoms associated with their medication for the respective diseases. The EI in patients with rheumatism and ankylosing spondylitis was 0.94, which is consistent with previous literature [3, 5]. The EI in other patient populations, such as those with antidepressants, diabetes, and psoriasis, ranged from 0.87 to 0.98, all above the cutoff level of 0.8, indicating a high efficacy of LASIK in these patients. Schallhorn et al. [6] reported a 76.8% efficacy in LASIK eyes with well-controlled collagen-vascular and other immune-mediated inflammatory diseases. While they did not form subgroups for refractive outcomes, our results align with their overall findings for all patient groups.

Two studies have evaluated LASIK safety and efficacy in patients with systemic rheumatic diseases. Alio et al. [5] found that LASIK surgery is safe and effective with well-controlled diseases but emphasized the need for disease control at least three months preoperatively. Cobo-Soriano et al. [3] also found LASIK safe in patients with stable diseases, mild extraocular involvement, and well-controlled medications, emphasizing the importance of adequate disease control before refractive treatment. They reported only mild complication, such as microfolds of the flap or interface reactions, which healed with topical therapy. Despite the promising results, the authors of the study recommend excluding patients with active autoimmune diseases from LASIK and draw attention that their findings are limited to patients with controlled and stable systemic diseases.

The results of our study suggest good predictability of LASIK in all patient populations, except for those patients taking antidepressants, who showed reduced predictability. According to Cobo-Soriano et al. [3] patients with collagen-vascular disease showed a lower predictability due to undercorrection and subsequent refractive regression. However, it should be noted that the sample sizes of the different studies were different from ours and some patients were lost during the follow-up, which makes direct comparisons difficult.

The retreatment rate for patients with chronic inflammatory bowel disease and diabetes was comparable to or slightly higher than rates reported in the literature [3, 9]. Similarly, retreatment rates for patients with psoriasis, rheumatoid arthritis, neurodermatitis, and hay fever were slightly higher than those reported in previous studies [3]. Interestingly, there was no significant difference in retreatment rates between patients with depression and the control group, despite previous research suggesting that depression may lead to increased dissatisfaction with postoperative results [10].

On the one hand, refractive outcomes of the diabetic group were satisfying, which is consistent with previous studies [9]. However, it is recommended that only patients with well-controlled blood sugar levels and without systemic or ocular diabetic complications be considered for LASIK surgery. The type of diabetes did not seem to have a significant impact on the outcome of LASIK surgery [11]. On the other hand, patients with hay fever showed statistically significant worse refractive results, which could be attributed to dry eye syndrome [12]. Patients with allergies have a higher risk of developing dry eyes, and medication with antihistamines also contributes to the development of dry eyes [13]. Therefore, careful preoperative screening and postoperative follow-up are important to minimize complications. Patients should be informed of their specific risk for complications after LASIK surgery in addition to the general risks.

One limitation of our study is the short follow-up period of only three months, which may not have been sufficient to detect all possible complications. Although most complications tend to occur within the first few weeks or months [14, 15], it is possible that some complications may have arisen beyond this period. Additionally, the small size of patient groups with different systemic diseases may limit the generalizability of the study’s findings to larger populations. Nevertheless, the unique inclusion of patients with systemic diseases interested in refractive treatment still makes a valuable contribution to the literature.

This study aimed to gain further insights into the safety, efficacy, and predictability of LASIK surgery in controversial patient populations. In conclusion, we found that selected patients with certain systemic conditions, such as disease inactivity and the absence of ocular involvement, can safely undergo LASIK surgery and achieve comparable refractive outcomes to healthy individuals. We need more research and international publications on treatment outcomes after LASIK in patients with systemic diseases to increase the evidence in the treatment of this challenging patient populations.