Presumed Unindicated Implantation of Posterior Chamber Phakic Intraocular Lens

Background

Refractive error is a leading cause of reversible visual impairment worldwide, and corrective refractive surgery is one of the most frequently used ocular surgeries worldwide. There are several procedures to correct refractive errors. These include laser vision correction and lens-based procedures [1–3]. Comparative articles on toric implantable collamer lens (T-ICL) vs LASIK for myopia >−3 D showed either nonsignificant differences or significant superiority of the T-ICL over LASIK in terms of visual performance (safety, efficacy, predictability, and stability). This difference is likely explained by the less induced high-order aberrations and better contrast sensitivity in T-ICL over LASIK [3]. We present the management of a case of a young adult woman with high myopic astigmatism and anisometropia who was lost to follow-up for several years and then underwent ICL (STAAR Surgical, Monrovia, CA, USA) surgery elsewhere. Eventually, she presented with low best-corrected vision, high vault, shallow anterior chambers, and a picture of cone-rod dystrophy.

Case Report

A 23-year-old woman, who was lost to follow-up in our hospital when she was 9 years of age, then presented to the dystrophy clinic with poor vision following bilateral implantation of ICL elsewhere. At 9 years old, her refraction was −6.50+3.00×105°, with the best corrected visual acuity (BCVA) of 20/30 in the right eye and −10.00+4.00×80°, and BCVA of 20/40 in the left eye. She had a younger sister with a similar manifestation. At 18 years of age, she underwent implantable collamer lens implantation. By the age of 23 years, her vision deteriorated. She noticed that the colors appeared washed out and had poor discrimination of objects. On presentation at the retinal dystrophy clinic, her uncorrected distance visual acuity (UCVA) was 4-6/200 and 2-3/200 in the right and left eye, respectively. The BCVA was 4-6/200 with a refraction of −0.50–1.00×15° in the right eye and 2-3/200 with a refraction of +2.00-0.50×155° in the left eye. Slit lamp examination indicated a clear cornea, pigment deposition on the endothelium, and anterior bowing of the iris, observed bilaterally. The anterior chamber depth was shallow in both eyes. Fundoscopic examination of both eyes revealed bull’s eye maculopathy with atrophy, chorioretinal atrophy nasal to the disc, attenuated vessels, and mild optic disc pallor. Bilateral loss of the macular ellipsoid zone was observed with optical coherence tomography (OCT). Hyporeflection in the central macula and anterior to the arcades was observed with fluorescein angiography (Figure 1). The anterior chamber depth, measured with the Pentacam (Oculus Gmbh, Wetzlar, Germany), was 1.67 mm and 2.34 mm in the right and left eye, respectively. The intraocular pressure measurement was 16 mm Hg, bilaterally. In her case, a diagnosis of autosomal recessive cone-rod dystrophy (homozygous variant CFAP418) was made [4]. At the age of 23 years, she was referred to the anterior segment clinic for ICL removal.

Owing to shallow anterior chambers, excessive vaulting (greater than 750 microns), and bowing of the iris (Figure 2), bilateral removal of the ICLs (EVO-design with a central hole; STAAR Surgical Inc., Monrovia, CA, USA) on separate visits was performed to prevent iris chafing and resultant loss of pigment. Both explanted ICLs measured 13.2 mm in diameter. Postoperatively, the vision remained unchanged. The anterior chamber depth, measured with the Pentacam (Oculus Gmbh, Wetzlar, Germany), improved to 2.42 mm and 2.37 mm in the right eye and left eye, respectively. Unfortunately, we did not have the opportunity to measure her preoperative anterior chamber depth for retrospective calculation of the appropriate ICL size based on the STAAR nomogram. We had only white-to-white measurements of the right and left eye, which were 12.0 mm and 12.10 mm, respectively. Postoperative gonioscopy indicated open angles with no pigmentation bilaterally. This finding raised the question of whether or not the preoperative anterior chamber depth was the same as the postoperative depth. The manufacturer’s recommendations state that the anterior chamber depth should be at least 2.80 mm, as measured from the endothelium [2].

Discussion

Many patients consider wearing glasses and contact lenses as an obstacle in their daily life, both cosmetically and functionally [5]. Hence, refractive surgery for patients ≥ 21 years old is a consideration, including cataract surgery and clear lens exchange as therapeutic interventions, which allow for insurance coverage [6]. Before considering intraocular surgery, the patient should undergo a thorough ophthalmic examination. Preoperative examination usually includes documentation of UCVA, BCVA, and measurement of refractive error. Intraocular lens implantation, or ICL implantation for a suitable patient, generally results in a satisfactory visual outcome. In cases in which an unexplained drop of vision occurred after refractive surgery, a detailed history should be taken (especially the presence of a family history of vision loss), a thorough funduscopic examination must be performed, and referral to specialized services, such as a dystrophy clinic or OCT and electrophysiology studies, might be considered. In our case, cone-rod dystrophy became apparent during the primary-school years [4]. Typical funduscopic findings are present and can therefore be noticed before adulthood.

Before scheduling a patient for a refractive surgical procedure, the ophthalmologist must ensure that the patient understands the potential risks of the procedure and has realistic expectations for the postoperative level and quality of uncorrected visual acuity [5]. In our case, underlying cone-rod dystrophy caused a poor visual outcome, and the large diameter ICL size caused high ICL vaulting. Around 95% of ophthalmologists have faced malpractice claims during their medical practice, with cornea and refractive surgeons facing the majority of legal action. This can be attributed to the elective nature of surgery performed by corneal and refractive surgeons. Furthermore, patients who undergo elective refractive surgeries are usually healthy and have high expectations about their outcomes and recovery [7]. Therefore, if a complication arises or the outcome does not match the patient’s expectation, this will psychologically impact the patient and can affect the surgeon’s credibility.

Regularly conducting morbidity and mortality meetings is a valuable tool to ensure that the highest level of care is provided to patients [8,9]. Unfortunately, most ophthalmology practices do not regularly hold those meetings. This might be due to the elective, non-life-threatening nature of ophthalmic surgery [9]. Additionally, morbidity and mortality meetings are essential in providing continuous education for healthcare providers, avoiding adverse events, promoting patient safety, and potentially optimizing the patient experience [8,9]. For these reasons, we advise that morbidity and mortality meetings should become an essential part of both public and private ophthalmology practices.

Conclusions

Refractive surgery is considered a therapeutic procedure that can dramatically alter patient-related quality of life by reducing the burden of glasses and contact lenses. A detailed preoperative assessment and the setting of realistic patient expectations are mandatory to avoid unnecessarily patient dissatisfaction, potential complications, and potential litigation. Although not absolutely contraindicated, refractive surgery in patients with permanent vision loss from irreversible retinal pathology is not recommended. Inappropriate patient and intraocular lens size selection are important and potentially preventable causes of morbidity that are becoming more recognized.