Outcomes of Refractive Lens Exchange: A Review of Cases

Refractive lens exchange (RLE) is increasingly offered as a refractive surgical option for selected patients who are poor candidates for LASIK and other less invasive procedures. In patients for whom the risk level inherent in intraocular surgery is acceptable, RLE can provide rapid visual rehabilitation and stable postoperative refraction.

Some surgeons^1,2 have expressed concern regarding the use of RLE in highly myopic patients, citing an unacceptably high risk of postoperative retinal detachment of 8% to 9.6%, although more recent reports^3-5 have cited lower rates of postoperative retinal detachment, from 2.3% to 3.5%.

Our own experience with RLE in patients with a wide range of refractive errors seemed to be at odds with reports of high rates of retinal complications, so we recently reviewed our results with the procedure, beginning 15 years ago.

RETROSPECTIVE STUDY
We retrospectively analyzed the refractive outcomes and retinal findings in 317 eyes of patients who underwent RLE by a single surgeon from 1993 to 2000. Follow-up was at least 5 years. Patients ranged in age from 26 to 80 years. Preoperative sphere ranged from -21.50 to 11.50 D, and cylinder from 0 to 5.75 D. Axial lengths ranged from 20.28 to 29.7 mm. The range of IOL power was from 4.00 to 30.00 D; in some patients who needed higher power, piggybacked IOLs were used.

To be included in this review, patients had to have BCVA of 20/40 or better preoperatively. (The 80-year-old patient presented with BCVA of 20/20 and desired RLE.) A few patients in the population had amblyopia, but none had BCVA worse than 20/40. Patients with any of the following pathologies were excluded: preoperative systemic disease, such as diabetes; corneal pathology, such as Fuchs corneal dystrophy or cornea guttata; or retinal pathologies, such as age-related macular degeneration.

Any patients in whom preoperative retinal pathology, such as small tears, were seen were independently evaluated by one of two retina specialists in the lens surgeon's practice. The retina specialists treated the pathology as appropriate before clearing the patients for surgery.

Modern phacoemulsification equipment and a clear corneal phaco technique were used in all patients.

RESULTS
Preoperatively, 206 eyes (65%) in the study were myopic; 105 (33%) were hyperopic, and six (2%) had mixed astigmatism with spherical equivalents near emmetropia. In the eyes with mixed astigmatism, toric IOLs were used.

Mean preoperative decimal UCVA (standard deviation) was 0.179 (±0.16). Mean preoperative BCVA was 0.703 (±0.19).

Postoperatively, mean UCVA improved to 0.705 (±0.24) and mean BCVA to 0.848 (±0.19). Therefore, the postoperative mean UCVA was equivalent to the preoperative mean BCVA (Figure 1).

Posterior capsulotomy was performed in 36% of eyes in the study. Capsulotomy was most frequent in myopic eyes, with 42% undergoing Nd:YAG, followed by 40% in the mixed astigmatic or emmetropic eyes and 16% in hyperopic eyes.

In the study, 4.5% of eyes were referred preoperatively for retinal evaluation. Of these, 57% were treated, which was 2.6% of the total eyes in the study. Retinal detachment occurred postoperatively in one patient (0.3%) and cystoid macular edema (CME) in two (0.6%).

Discussion
The current literature suggests an average capsulotomy rate of approximately 10% following modern cataract surgery. In the period of this study, the literature suggests a rate of approximately 33% after cataract surgery. The rate in this study was slightly higher than that, but this population of RLE patients was younger than the population for cataract surgery; development of posterior capsular opacification was more prevalent in this relatively younger population.

The rate of retinal detachment in this series was low compared with other studies in the literature, considering that almost two-thirds of patients were myopic. Additionally, these were patients who were not candidates for LASIK, so the myopic patients tended to have high myopia, a risk factor for retinal detachment. One reason for the low retinal complication rate may have been the way preoperative retinal tears and other pathology were treated; only the area of pathology received laser treatment, not the whole retina.

Visual results in the series were good, with mean postoperative UCVA equivalent to the mean preoperative BCVA. These surgeries were done with modern phaco equipment and techniques between 1993 and 2000, although obviously techniques and technologies have undergone further advances since that time. The patients were screened carefully for retinal pathology preoperatively and followed carefully postoperatively; they were seen by the operating surgeon at 1 day, 1 or 2 weeks, 1 month, and 3 months, and by the retina specialist again at 6 months as needed if they were seen preoperatively or had postoperative issues.

Patients in the study were treated prophylactically, both pre- and postoperatively, to prevent complications. They received a topical steroid and topical fluoroquinolone antibiotic four times a day for 3 days preoperatively, and the same two medications four times a day for 2 weeks postoperative, followed by the steroid twice a day for an additional 2 weeks. My current regimen today adds a topical non-steroidal antiinflammatory drug (NSAID) both pre- and postoperatively.

CONCLUSION
This series suggests that RLE can be offered as a relatively safe option for patients who are not good candidates for less invasive refractive surgical procedures. Keys to success with RLE include careful preoperative screening and treatment for retinal pathology, a thorough prophylactic topical drug regimen, the use of modern phacoemulsification equipment and techniques, and close and vigilant follow-up.

Karl G. Stonecipher, MD, is Director of Refractive Surgery at The Laser Center in Greensboro, North Carolina. Dr. Stonecipher may be reached at tel: +1 336 288 8823; e-mail: stonenc@aol.com. Dr. Stonecipher states that he has consulted, served on the speaker's board, or received travel or research funding from these companies: Advanced Medical Optics, Inc.; Alcon Laboratories, Inc.; Allergan, Inc.; Inspire; LifeGuard; Nidek; Vistakon; and WaveLight.

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