Objective
To assess the visual complaints, reasons, and patient satisfaction for multifocal intraocular lens (IOL) explantation.
Design
Retrospective observational case series.
Methods
This study evaluated 50 eyes of 37 patients who underwent multifocal IOL explantation followed by IOL implantation. Before and 3 months after IOL exchange surgery, we investigated the symptoms, reasons, patient demographics, clinical results, and patient satisfaction in eyes undergoing multifocal IOL explantation. Data collected included preoperative subjective and objective findings, reasons, IOL type, postoperative course, and patient satisfaction.
Results
The most common complaints for IOL explantation were waxy vision, followed by glare and halos, blurred vision at far, dysphotopsia, blurred vision at near, and blurred vision at intermediate. The most common reasons for IOL explantation were decreased contrast sensitivity, followed by photic phenomenon, unknown origin including neuroadaptation failure, incorrect IOL power, preoperative excessive expectation, IOL dislocation/decentration, and anisometropia. The axial length was 25.13 ± 1.83 mm. Of the explanted multifocal IOLs, 84% were diffractive and 16% were refractive. Monofocal IOLs accounted for 90% of the exchanged IOLs. Patient satisfaction was significantly improved from 1.22 ± 0.55 preoperatively to 3.78 ± 0.97 postoperatively, which was graded on a scale of 1 (very dissatisfied) to 5 (very satisfied) (Wilcoxon signed-rank test, P < .001).
Conclusions
Multifocal IOL explantation was required in some patients undergoing multifocal IOL implantation. IOL exchange surgery appears to be a feasible surgical option for dissatisfied patients with persistent visual symptoms after multifocal IOL implantation.
Multifocal intraocular lens (IOL) implantation has become widely accepted as an effective method for the correction of presbyopia with cataract, since this IOL increases depth of field and enhances near vision. However, its implantation may lead to decreased visual acuity and visual artifacts, such as glare, halos, dysphotopsia, and dissatisfaction with quality and sharpness of vision even after the use of spectacles and contact lenses. Despite high levels of overall patient satisfaction after multifocal IOL implantation, some patients have been dissatisfied with this surgical procedure, even when uncorrected visual acuity was excellent. A few studies have examined the detailed etiology of dissatisfaction after multifocal IOL implantation and have suggested that the residual ametropia and posterior capsular opacification were the major sources of dissatisfaction after this surgical procedure. The refractive errors and posterior capsular opacification can be successfully treated by spectacle correction, by keratorefractive surgery such as laser in situ keratomileusis (LASIK), or with neodymium–yttrium-aluminum-garnet laser capsulotomy; whereas waxy vision and photic phenomena, both of which were common visual complaints in multifocal IOL-implanted eyes, can be treated only by IOL exchange surgery, especially when the postoperative visual complaints are severe. Although multifocal IOL explantation is performed infrequently, it nevertheless is performed, and so should be considered for the sake of the patient. Accordingly, it is of epidemiologic importance to assess the complaints about, and to consider the etiology of, multifocal IOL explantation, since both might offer essential insights that could contribute to the selection of an appropriate surgical approach. At present, only 1 study, performed by Galor and associates, has reported the surgical outcomes of multifocal IOL explantation, but the reasons for, and the patient satisfaction with, the IOL exchange have not yet been fully evaluated. No study detailing the etiology and reporting the patient satisfaction with the IOL exchange after multifocal IOL implantation has to date been published. The purpose of the current study is to assess retrospectively the demographics and clinical outcomes, including the patient’s symptoms, the reasons for selecting this method, and the patient satisfaction with multifocal IOL explantation in a large cohort of patients presenting at major clinical centers in Japan.
Methods
Patient Population
This retrospective review of data was approved by the Institutional Review Board at Kitasato University and adheres to the tenets of the Declaration of Helsinki. Our Institutional Review Board waived the requirement for informed consent for this retrospective study. The case series covered 50 eyes of 37 patients (14 men and 23 women) who underwent removal of a multifocal IOL and implantation of a multifocal or a monofocal IOL, at 10 major medical institutions (Kitasato University Hospital; Keio University Hospital; Tokyo Dental College, Suidobashi Hospital; Hayashi Eye Hospital; Inoue Eye Hospital; Tane Memorial Hospital; Kozawa Eye Hospital; Okamoto Eye Clinic; Nagoya Eye Clinic; and Minatomirai Eye Clinic), between January 1, 2005 and December 31, 2012. This study was conducted as a collaborative work of the Survey Working Group of the Japanese Society of Cataract and Refractive Surgery.
Survey
The primary cataract surgery involved standard phacoemulsification with multifocal IOL implantation in all cases. The IOL explantation and IOL implantation were performed by different surgeons using various IOL explantation techniques (folding, cutting, or removing whole). No particular surgical protocol was followed for IOL explantation. Patient demographics and clinical outcomes, including the visual complaints and causes of IOL explantation, duration from IOL implantation to IOL explantation, explanted IOL type, implanted IOL type, and patient satisfaction, were documented on the basis of the medical records supplied by the referring ophthalmic surgeons. The visual symptoms of the patients were classified as follows: blurred vision (blurred vision at far, intermediate, and/or near distances, and waxy vision), photic phenomena (glare, halos, and/or dysphotopsia), and both (multiple answer allowed). Glare and halos were defined as reduced sharpness of vision in bright lights and a dim disk of light or a blurred circle surrounding the light source image, respectively. Dysphotopsia is characterized by brightness, streaks, and rays emanating from a central point source of light, sometimes with a diffuse hazy glare (positive dysphotopsia), or a subjective darkness or shadow, which may be arc-shaped, usually in the temporal field of vision (negative dysphotopsia). Waxy vision was defined as being equivalent to blurred vision, regardless of the sighting distance after spectacle correction. The following are most of the reasons for IOL explantation: decreased contrast sensitivity, photic phenomena, incorrect IOL power, IOL dislocation/decentration, anisometropia, IOL opacification, pseudophakic bullous keratopathy, endophthalmitis, excessive preoperative expectation, and unknown origin including neuroadaptation failure (multiple answers allowed). Patient satisfaction for overall quality of vision was graded on a scale of 1 (very dissatisfied) to 5 (very satisfied), before and 3 months after IOL explantation. As a control group, we additionally assessed the patient satisfaction in 50 eyes undergoing standard phacoemulsification with monofocal IOL implantation. For the subgroup analysis of eyes whose contrast sensitivity was significantly decreased preoperatively, the contrast sensitivity function was also measured 3 months postoperatively with a contrast sensitivity unit (VCTS-6500; Vistech, Dayton, Ohio, USA) under photopic conditions. The test was performed with best spectacle correction at 2.5 m. From the contrast sensitivity, the area under the log contrast sensitivity function was determined as described previously.
Statistical Analysis
All statistical analyses were performed using StatView version 5.0 (SAS, Cary, North Carolina, USA). The Wilcoxon signed-rank test was used for statistical analysis to compare the pre- and postsurgical data. The Mann-Whitney U test was used to compare the data for satisfaction between the study and control groups. The Fisher exact test was used to compare the frequency of photic phenomena between the diffractive and refractive IOL-implanted groups. Each result is expressed as the mean ± standard deviation (SD), and a value of P < .05 was considered statistically significant.
Results
The demographics of the study population are summarized in Table 1 . The total number of successful multifocal IOL implantations at 10 medical institutions between January 2005 and December 2012 was 4254 (refractive IOL: 569, diffractive IOL: 3685), and the estimated number of patients with visual complaints who did not receive multifocal IOL explantation was 306. These patients did not undergo multifocal IOL explantation, because most complaints were not severe and/or gradually improved over time. The mean patient age at the time of surgery was 65.5 ± 8.2 years (range, 50–82 years). The logarithm of the minimal angle of resolution (logMAR) uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were 0.23 ± 0.27 (range, −0.18 to 1.00) and −0.01 ± 0.16 (range, −0.30 to 0.52), respectively. The axial length was 25.13 ± 1.83 mm (range, 22.40–30.83 mm). Patient satisfaction before IOL explantation was 1.22 ± 0.55 (range, 1–3), which was significantly lower than that after monofocal IOL implantation (3.90 ± 0.89 [range, 2–5]) (Mann-Whitney U test, P < .001).
| Demographic (Mean ± Standard Deviation) | |
|---|---|
| Age (y) | 65.5 ± 8.2 |
| Sex (male : female) | 14:23 |
| LogMAR UDVA | 0.23 ± 0.27 |
| LogMAR CDVA | −0.01 ± 0.16 |
| Manifest spherical equivalent (D) | −0.10 ± 0.65 |
| Manifest cylinder (D) | 0.73 ± 0.63 |
| Mean keratometry (D) | 43.2 ± 2.2 |
| Axial length (mm) | 25.13 ± 1.83 |
| Concomitant eye disease (N = 50 eyes) | |
| Dry eye | 8 eyes (16%) |
| Post-LASIK | 6 eyes (12%) |
| Post-Nd:YAG capsulotomy | 5 eyes (10%) |
| Glaucoma | 4 eyes (8%) |
| Epiretinal membrane | 1 eye (2%) |
| Macular atrophy | 1 eye (2%) |
| Symptoms (N = 50 eyes) | |
| Bilateral | 26 eyes (52%) |
| Unilateral, unilateral IOL | 21 eyes (42%) |
| Unilateral, bilateral IOLs | 3 eyes (6%) |
All patients had subjective visual symptoms before the IOL exchange, the most common being waxy vision (29 eyes, 58%), followed by glare and halos (15 eyes, 30%), blurred vision at far (12 eyes, 24%), dysphotopsia (10 eyes, 20%), blurred vision at near (9 eyes, 18%), and blurred vision at intermediate (3 eyes, 6%) ( Table 2 ). Glare and halos after diffractive and refractive IOL implantation were found in 12 eyes (29%) and 3 eyes (38%), respectively ( P = .63, Fisher exact test). Dysphotopsia after diffractive and refractive IOL implantation was found in 7 eyes (17%) and 3 eyes (38%), respectively ( P = .33). Despite these symptoms, 19 eyes (38%) and 42 eyes (84%) before multifocal IOL explantation had, respectively, UDVAs and CDVAs of 20/25 or better. Before multifocal IOL explantation, 15 eyes (30%) and 34 eyes (68%) had a UDVA and a CDVA of 20/20 or better, respectively. The types of explanted and implanted IOLs are shown in Table 3 . Explanted IOLs accounted for 42 (84%) and 8 (16%) eyes of the diffractive and refractive multifocal IOLs, respectively. Forty-five (90%) of the implanted IOLs were monofocal IOLs. The remaining 5 (10%) of the implanted IOLs were multifocal IOLs owing to incorrect IOL power. The most common reasons for IOL explantation were decreased contrast sensitivity (18 eyes, 36%), followed by photic phenomena (17 eyes, 34%), unknown origin including neuroadaptation failure (16 eyes, 32%), incorrect IOL power (10 eyes, 20%), excessive preoperative expectation (7 eyes, 14%), IOL dislocation/decentration (2 eyes, 4%), and anisometropia (2 eyes, 4%) ( Table 4 ). The time to the IOL exchange after the initial IOL implantation was 7.9 ± 9.2 months (range: 3 days to 40.5 months). The targeted refraction was −0.37 ± 0.88 diopters (D) (range: −5.00 to 0.23 D). The targeted refraction was emmetropia in 41 eyes (82%). Sixty percent of the patients underwent multifocal IOL explantation at the same institution where the initial IOL implantation was performed, and 40% of the patients underwent this surgery at other institutions. The surgical techniques for IOL explantation were cutting (48 eyes, 96%), and removing the whole (2 eyes, 4%); and the implanted IOL locations were in-the-bag placement (38 eyes, 76%), out-of-the-bag placement without optic capture (11 eyes, 22%), and sulcus placement with scleral suturing (1 eye, 2%). Three eyes (6%) required triamcinolone-assisted anterior vitrectomy, and 1 eye (2%) developed a slight, asymptomatic IOL dislocation attributable to partial zonular dehiscence. No other vision-threatening complication was seen at the time of surgery. Three months after multifocal IOL explantation, 24 eyes (48%) and 46 eyes (92%) had UDVAs and CDVAs, respectively, of 20/25 or better, and 24 eyes (42%) and 43 eyes (86%) had UDVAs and CDVAs, respectively, of 20/20 or better. In the subgroup analysis of contrast sensitivity, the area under the log contrast sensitivity function was significantly increased, from 0.90 ± 0.38 (range, 0.30–1.39) preoperatively to 1.26 ± 0.30 (range, 0.71–1.63) 3 months postoperatively ( P = .003, Wilcoxon signed-rank test). There was also a significant increase in contrast sensitivity at all 5 spatial frequencies after multifocal IOL explantation ( Figure ). Patient satisfaction was significantly improved to 3.78 ± 0.97 (range, 2–5) after multifocal IOL explantation (Wilcoxon signed-rank test, P < .001), which was not significantly different from that after monofocal IOL implantation (Mann-Whitney U test, P = .524). Even after IOL explantation, only 2 patients were dissatisfied—and they only slightly so—with the quality of vision because they had blurred vision at far, or waxy vision, but they elected to proceed without any surgical intervention because the symptoms were not severe.
| Visual Complaints Before Multifocal IOL Explantation | |
|---|---|
| Blurred vision | |
| At far | 12 eyes (24%) |
| At intermediate | 3 eyes (6%) |
| At near | 9 eyes (18%) |
| Waxy vision | 29 eyes (58%) |
| Photic phenomena | |
| Glare/halos | 15 eyes (30%) |
| Dysphotopsia | 10 eyes (20%) |
| Visual Complaints of Dissatisfied Patients After Multifocal IOL Explantation | |
|---|---|
| Blurred vision | |
| At far | 1 eye (2%) |
| Waxy vision | 2 eyes (4%) |
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