RRD after LASIK must be managed promptly

If rhegmatogenous retinal detachment is managed promptly, good vision can result.

Issue: November 1, 2000

SAN BERNARDINO, CARACAS, Venezuela - Rhegmatogenous retinal detachment (RRD) after laser in situ keratomileusis (LASIK) is infrequent, and if managed promptly, good vision can result.

Recently, a study was conducted to determine the incidence of RRD after LASIK. "No cause-effect relationship between LASIK and RD was proven in this study, but [I] recommend that patients scheduled for refractive surgery undergo a thorough dilated indirect fundus examination with scleral depression and treatment of any retinal lesions predisposing them to the development of RRD before LASIK surgery is performed," said J. Fernando Arevalo, MD, in practice here.

To determine the incidence of RRD after LASIK, Dr. Arevalo and colleagues reviewed medical records and obtained follow-up information on all patients in their files with RRD after LASIK between August 1995 and August 2000 at four institutions. During the study period, 38,823 LASIK procedures were performed by five experienced refractive surgeons. These patients underwent surgical correction of between 0.75 and 29.00 D of myopia. Follow-up schedule was postop day 1, 3 months postop, 12 months postop and yearly thereafter.

"We excluded a patient who developed RRD in an eye that suffered a corneoscleral perforation with the surgical microkeratome when the corneal flap was being performed," he said. This left 33 eyes in 27 patients that developed RRD after LASIK.

Preop exams

---Fundus photograph of a subtotal infero-temporal retinal detachment (macula off) after LASIK. There was a partial posterior vitreous detachment, a horseshoe retinal tear at 8 o'clock and a retinal hole at the same location.

"LASIK was performed on patients with no history of refractive surgery, keratoconus, cataract surgery, proliferative diabetic retinopathy or collagen vascular disease. Preoperative examinations included a thorough dilated fundus examination with scleral depression and treatment of any retinal lesions predisposing patients to the development of RD. Proparacaine hydrochloride 1% drops were instilled into the eye to be treated," he said.

"A rigid eyelid speculum was used. Two radial marks at the 12 and 5 o'clock positions were made with gentian violet with an eight-point radial marker. The Chiron automated corneal shaper (Bausch & Lomb Surgical; Claremont, Calif.) or the Moria One microkeratome suction ring (Moria; Doylestown, Pa.) was placed in the eye concentric to the pupil. The suction pump was activated to a pressure of 22 to 24 mm Hg," he added.

Using a Barraquer tonometer, intraocular pressures of approximately 60 mm Hg were confirmed. Before placing the automated corneal shaper microkeratome head, a few drops of irrigating solution were instilled. "Then, the microkeratome head was placed into the groove of the suction ring, and a 160-µm flap was dissected by activating the forward motion on the foot pedal. A slow smooth pass was performed until the microkeratome reached the permanent stop. Reverse action on the foot pedal permitted retraction of the microkeratome head. The microkeratome head and the suction ring were removed together, and the corneal flap was elevated using a forceps or spatula to expose the underlying corneal stroma," he explained.

A microsurgical sponge was used to dry the stromal bed. The desired treatment parameters were entered into the laser's computer, and laser ablation was performed in the stromal bed using the Chiron excimer laser or the Coherent Schwind Keraton 2 (Coherent; Santa Clara, Calif.).

"A pars plana vitrectomy was performed in 12 patients using a Premiere [Bausch & Lomb Surgical] or a Millennium [Bausch & Lomb Surgical] vitreous cutter. After vitrectomy, sulfur hexafluoride gas was used in 12 patients. In 20 patients, a scleral buckling procedure was performed using HGM's PC EDO argon laser (HGM; Salt Lake City, Utah) using the indirect delivery system. Pneumatic retinopexy was performed using the same argon laser with the indirect delivery system and sulfur hexafluoride gas," he added.

The average age of the patients was 39.2 years, with a range of 16 to 60. Half of the patients were women, and half were men. Patients were followed for a mean of 48 months after LASIK, with a range of 6 to 60 months. "The incidence of RRD determined in our study was 0.08%," Dr. Arevalo said.

Surgical outcomes

---Postoperative fundus photograph of a myopic eye that developed a rhegmatogenous retinal detachment with proliferative vitreo-retinopathy (PVR) after LASIK. Vitrectomy and silicone oil injection was successfully performed.

Vitreo-retinal surgery to repair RRD after LASIK was performed at a mean of 56 days (range: 1 day to 18 months) after the onset of visual symptoms. The mean follow-up after retinal surgery was 14 months (range: 3 to 34 months), and 38.7% of the 31 eyes (two patients refused surgery) had a final best corrected visual acuity (VA) of 20/40 or better. The final VA was better than 20/200 in 77.4% of eyes. Poor VA (20/200 or worse) occurred in 22/6% of eyes. Reasons for poor VA included the development of proliferative vitreo-retinopathy (PVR), epiretinal membrane, chronicity of RRD, new breaks and cataract.

The long interval between the onset of symptoms and RRD surgery may be responsible for some of the factors (including a 19.3%% rate of PVR) that contributed to poor final VA in more than 20% of cases. In some of patients, Dr. Arevalo said, there may have been some delay in the referral to the vitreo-retinal specialists due to a belief that the visual symptoms were related to a refractive or corneal problem after LASIK. In addition, other factors related to high myopia (including myopic degeneration and amblyopia) might also influence the final functional results regardless of the high anatomic success rate, he said.

Retinal detachment

This is a much lower incidence of RRD than in myopes in general. Dr. Arevalo attributes this finding to the fact that his refractive surgery patients undergo preoperative examinations including a thorough dilated indirect fundus examination with scleral depression and treatment of any retinal lesions predisposing them to RRD before LASIK is performed.

RRD occurred between 12 days and 60 months after LASIK. "Eyes that developed RRD had between 1.50 and 16.00 D of myopia before LASIK. Retinal detachments were managed with vitrectomy, cryoretinopexy, scleral buckling, argon laser retinopexy and pneumatic retinopexy techniques," he said.

Most of the retinal detachments and retinal breaks occurred in the temporal quadrants. "These are noteworthy findings because the surgical microkeratomes used in LASIK to create the corneal flap in our study have a temporal handle that may be responsible for extra pressure on that side of the eye," he said.

"Because of these findings, we recommend that patients scheduled for LASIK be carefully examined by indirect ophthalmoscopy and scleral depression under pupillary dilation to detect any myopic peripheral lesions that require immediate treatment before LASIK is performed," he said.

In summary, Dr. Arevalo said, the study suggests that RRD after LASIK for the correction of myopia is infrequent, but it is a serious complication. In 45.8% (11/24) of eyes, VA decreased 2 or more lines after vitreo-retinal surgery, when compared with VA after LASIK.

For Your Information:
J. Fernando Arevalo, MD, can be reached at the Clinica Oftalmologica Centro Caracas, Centro Caracas PH-1, Av. Panteon, San Bernardino, Caracas 1010, Venezuela; 58-2-576-8687; fax: 58-2-576-8815. Dr. Arevalo does not have a direct financial interest in any product mentioned in this article, nor is he a paid consultant for any company mentioned.