Retinal Detachment After Neodymium:YAG Laser Posterior Capsulotomy

Retinal Detachment After Neodymium:YAG Laser Posterior Capsulotomy Lynda Rickman-Barger, B.A., Craig W. Florine, M.D., Rhondi S. Larson, M.D., and Richard L. Lindstrom, M.D.

We reviewed the records of 397 patients who had undergone Nd:YAG laser posterior capsulotomy between July 1983 and August 1988. Of the 366 eyes that had been followed up for three months or more, 13 (3.6%) developed a retinal detachment after capsulotomy; of these 13 detachments, 11 (84.6%) occurred within the first year. The combination of male gender with axial myopia (i!:25.00 mm), a history of lattice degeneration, or a history of retinal detachment in the fellow eye was a significant risk factor for the development of retinal detachment after YAG capsulotomy. EXTRACAPSULAR CATARACT EXTRACTION has recently surpassed intracapsular cataract extraction as the standard technique in cataract surgery. Although several advantages related to the retention of the posterior capsule have been responsible for this transition, the technique is also commonly complicated by opacification of this same structure. An 18% to 50% rate of capsular opacification has been reported after the extracapsular technique. The resultant decrease in visual acuity necessitates opening of the posterior capsule to restore clear vision in affected patients. Posterior capsulotomy is currently achieved more commonly by use of the neodymium:YAG laser rather than the surgical knife-needle technique. Although YAG capsulotomy may offer a safer, less invasive approach, the procedure is not without complications. Anterior segment complications include increased intraocular pressure, damage to the corneal endothelium,

Accepted for publication Feb. 3, 1989. From the Department of Ophthalmology, University of Minnesota, Minneapolis, Minnesota. Reprint requests to Richard L. Lindstrom, M.D., 9-240 Health Sciences Unit C, Box 493 UMHC, 516 Delaware St. S.E., Minneapolis, MN 55455. ©AMERICAN JOURNAL OF OPHTHALMOLOGY

107:531-536,

iris hemorrhage, intraocular lens damage, and uveitis. Posterior segment complications include rupture of the anterior hyaloid face, cystoid macular edema, macular hole, retinal tear, and retinal detachment. Retinal detachment is a particularly threatening complication because of potential loss of vision. Previous studies have reported rates of this complication from 0.08% to 2%, J·6 but more recent reports (D. D. Koch, M.D., written communication, December 1988) indicate that the rate of retinal detachment may actually be much higher (Table 1). We undertook this study to identify risk factors that may predispose patients to retinal detachment after YAG capsulotomy, as well as to document the incidence of this complication.

Subjects and Methods After approval by the institutional human study review board, we reviewed the records of 397 consecutive eyes that had undergone Nd:YAG laser posterior capsulotomy at our institution from July 1983 to August 1988. All TABLE 1 INCIDENCE OF RETINAL DETACHMENT FOLLOWING ND:YAG POSTERIOR CAPSULOTOMY INCIDENCE INVESTIGATORS (YEAR)

(NO./TOTAL)

%

Aron-Rosa, Aron, and Cohn (1984)3

2/2,500

Johnson, Kratz, and Olson (1984)5

4/389

1.0

Keates, Steinert, and Puliafito (1984)'

2/526

0.4

Stark and associates (1985)2 Shah and associates (1986)4

11/2,110

0.5

5/3,000

0.2 2.1

Ficker and associates (1987)6 Koch and associates (unpublished data) (1988) Present study

MAY,

1989

12/582 5/122 13/366

0.1

4.1 3.6

531

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capsulotomies were performed with a Qswitched Nd:YAG laser. Of the 397 eyes, 366 (336 patients) had been followed up for a minimum of three months. Thirty-one eyes (30 patients) were lost to follow-up. Patients meeting the minimum follow-up criterion were divided into four groups. Group 1 consisted of 276 eyes that underwent posterior chamber lens implantation at time of cataract surgery; Group 2 included 72 aphakic eyes, with no intraocular lens implant; Group 3 included nine eyes with anterior chamber lenses; and Group 4 included the nine eyes for which lens status was unknown. The average followup time was 17.9 months (range, three to 50 months). Data collected for all eyes included gender, eye, age at capsulotorny, and total power required for capsulotomy. .. In addition to the above characteristics, the subgroup of patients with posterio~ chamber lens implants was evaluated for axial length, interval from implant surgery to capsulotomy, type of extracapsular cataract extraction, and vitreoretinal disease before capsulotomy. Information regarding the size of the capsulotomy and the status of the anterior hyaloid face was not available. Statistical analyses including independent t-tests and corrected chi-square calculations were performed by our institution's Department of Biometry.

Results Of 366 eyes, 13 (3.6%) developed rhegmatogenous retinal detachments after Nd:YAG posterior capsulotomy (Table 2). Ten of these eyes (ten patients) had posterior chamber impla~ts and three eyes (three patients) were aphakic. Hence, the incidence of retinal detachment within the posterior chamber implant subgroup was 3.6% (ten of 276), w~er~as the aphakic population yielded a 4.2% incidence (three of 72). The average interval from the capsulotomy to the retinal detachment was 5.79 months (range, one week to 25 months). Six detachments developed within the first two months, nine occurred within six months, and 11 occurred within one year after capsulotomy. Of the two remaining patients, one experienced retinal detachment just after the one year mark (12.25 months) and the other at 25 months. The incidence of retinal detachment among men was 6.2% (ten of 161), whereas the incidence among women was 1.5% (three of 205). This difference was statistically significant (P :s .05). The mean age of patients with a retinal detachment was 58 years (range, 21 to 85 years) compared to a mean age of 67 years (~ange, nine to 102 years) for the 353 patients without retinal complications. This difference demon-

TABLE 2 PATIENTS WITH RETINAL DETACHMENT

PATIENT NO., AGE (VRS), SEX

1,66, 2,50, 3,52, 4,21, 5,71,

M F M F M

6, 66, F 7,63, M 8,68, 9,55, 10,69, 11,85, 12,38, 13,34,

M M M M M M

EYE

L

R R R l R l R l R R R R

LENS STATUS'

PCl PCl PCl PCl PCl PCl PCl PCl PCl PCl Aphakic Aphakic Aphakic

'PCl, posterior chamber lens.

AXIAL LENGTH

TOTAL POWER

INTERVAL BETWEEN CATARACT AND ND:YAG CAPSULOTOMY

INTERVAL BETWEEN ND:YAG CAPSULOTOMY AND RETINAL DETACHMENT

(MM)

(MJ)

(MOS)

(MOS)

23.65 22.68 24.45 21.25 25.9 24.01 24.2

81.9 63 72 178.2 70.3

25.49 25.98 24.86

27 385.6 46.8 66.6 37.5 170 35.2 12.3

16.5 1.5 9.75 0.5 8 2.75 31.5 31.75 5.5 25 6 28 41

1.25 4.5 0.25 1.5 11 5.25 0.5 4.5 7.5 25 1.25 0.5 12.25

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Retinal Detachment After YAG Capsulotomy

strated a trend (P :5 .1) toward an increased incidence of retinal detachment in patients undergoing capsulotomy at a younger age. The mean total power required for capsulotomy in the 13 patients with retinal detachment was 95.9 m] (range, 12.3 to 385.6 mj) and in the 353 patients without retinal complications 99.2 m] (range, 8.6 to 540 mj), This difference was not statistically significant. Of the 12 patients who received >300 m] of laser power, one (8.3%) developed a retinal detachment, whereas 12 of 350 (3.4%) of those receiving :5300 m] of power developed a retinal detachment. This difference was also not statistically significant. The subgroup of 276 patients with posterior chamber lens implants was also evaluated independently. The ten eyes with retinal detachment (ten patients) with posterior chamber lenses were analyzed respective to the 266 remaining eyes in this subgroup. The incidence of retinal detachment in the men and women in this subgroup was 6.1 % (seven of 115) compared to 1.9% (three of 161), respectively. This difference was not statistically significant in this subgroup, perhaps because of the smaller sample size. There was no significant difference in total power required for capsulotomy between patients with retinal detachments (mean, 102.9 m]: range, 27 to 385.6 mn and those with attached retinas (mean, 91.4 m]: range, 9.1 to 512.2 ml), nor was there a significant difference in the incidence of retinal detachment in the groups receiving >300 m] com-

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pared to :5300 m] of power (one of six compared to nine of 266). The mean age of patients with retinal detachment was 58 years (range, 21 to 71 years), whereas for those without detachment it was 69 years (range, 21 to 99 years). Hence, although a trend toward younger age at capsulotomy in patients with retinal detachment was identified for the entire population, this trend became statistically significant (P :5 025) when the posterior chamber lens subgroup was evaluated independently. We also evaluated the method of cataract extraction performed, as well as the interval between intraocular lens implant surgery and capsulotomy with respect to the occurrence of retinal detachment. Of the 180 eyes that underwent planned extracapsular cataract extraction, four (2.2%) subsequently developed retinal detachment, whereas six of the 93 eyes (6.4%) that underwent phacoemulsification developed this complication. This difference was not statistically significant. The mean interval between cataract surgery and YAG capsulotomy was 12.9 months (range, zero to 32 months) in eyes that subsequently developed detachment. This was not significantly different from the interval in eyes that did not develop detachment of 17.4 months (range, zero to 86 months). Finally, several previously identified risk factors in the posterior chamber implant subgroup were analyzed for any association with retinal detachment (Table 3). The mean axial length for

TABLE 3 RISK FACTORS FOR RETINAL DETACHMENT AFTER ND:YAG CAPSULOTOMY IN PATIENTS WITH POSTERIOR CHAMBER LENS IMPLANTS

RISK FACTOR

Male gender ,;;60 years old at time of surgery Axial myopia 2:25.00 mm Lattice degeneration Previous retinal detachment in the fellow eye Male gender and axial myopia 2:25.00 mm Any combination of axial myopia 2:25.00 mm, previous retinal detachment in the fellow eye, or lattice degeneration Male gender and any combination of axial myopia 2:25.00 mm, previous retinal detachment in the fellow eye, or lattice degeneration

INCIDENCE(%) OF RETINAL DETACHMENT IN RISK FACTOR GROUP (No./ToTAL. %j

INCIDENCE (%) OF RETINAL DETACHMENT IN CONTROLGROUP (NO./TOTAL %)

STATISTICAL SIGNIFICANCE

7/115 6/105 3/36 1/9 1/14 3/17 5/52

(6.1%) (5.7%) (8.3%) (11.1%) (7.1%) (17.6%) (9.6%)

3/161 7/261 7/226 9/267

(1.9%) (2.7%) (3.1%) (3.4%)

.25 < P < .5 .25 < P < .5 .25 < P < .5 P> .75

9/262 7/245 5/210

(3.4%) (2.8%) (2.4%)

P> .9 P < .025 P < .05

4/24

(16.7%)

6/238

(2.5%)

P < .005

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eyes with retinal detachment was 24.25 mm (range, 21.25 to 25.98 mm) and for the eyes without detachment was 23.66 mm (range, 20.47 to 28.87 mm). The incidence of retinal detachment in patients with axial myopia (axial length ze 25.00 mm) was 8.3% (three of 36) as compared to an incidence of 3.1 % (seven of 226) in patients without axial myopia. This difference is not statistically significant. Because axial lengths were not available for 14 eyes, the total subgroup of patients with axial length data consists of 262 eyes. The incidence of retinal detachment in the subset of patients who were both male and had axial lengths ;;::25.00 mm was 17.6% (three of 17) and is significantly different (P :5 .025) from the incidence of 2.8% (seven of 245) in patients without detachment. Subgroups with other risk factors, such as a history of lattice degeneration or retinal detachment in the fellow eye before capsulotomy, were not found to have a significantly higher incidence of retinal detachment when compared to the patients without these risk factors (Table 3). However, there was a 9.6% (five of 52) incidence of retinal detachment in the group of patients who had one or more of the three risk factors (axial myopia ;;::25.00 mm, lattice degeneration, or previous retinal detachment in the fellow eye). This is significantly different (P :5 .05) from those who did not exhibit these risk factors before capsulotomy and had a 2.4% (five of 210) incidence of retinal detachment. The incidence of retinal detachment in the subset of patients who were both male and had one or more of the three risk factors was 16.7% (four of 24) compared to the incidence of 2.5% (six of 238) in the patients that did not have these characteristics. This is a highly significant difference (P < .005). Discussion

Early reports of the incidence of retinal detachment after Nd:YAG laser posterior capsulotomy were quite low. Most studies before 1987 reported a less than 1% incidence of retinal detachment after capsulotorny.!" In 1987, Ficker and associates" reported a 2% incidence, and in 1988, Koch, Liu, Gill, and Parke (unpublished data) found a 4.1 % overall incidence of retinal detachment after capsulotomy. In this retrospective study, the incidence of retinal detachment in all patients undergoing cap-

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sulotomy was 3.6%. Patients with posterior chamber lenses had a 3.6% incidence whereas aphakic patients demonstrated a 4.2% incidence of retinal detachment after YAG posterior capsulotomy (Table 1). Clearly, YAG laser posterior capsulotomy may not be as safe as previously thought. Posterior capsulotomy to create a clear visual axis is complicated by an increased incidence of retinal detachment regardless of the technique used to perform the capsulotomy. Reports on the incidence of retinal detachment after primary or secondary knife discission of the posterior capsule range from 2.3% to 6.1 % .7.10 Hence, the risk of retinal detachment associated with Nd:YAG laser capsulotomy does not appear to be greater than that associated with surgical discission. The average interval from YAG capsulotomy to the development of retinal detachment in our study was 5.79 months, a figure similar to that reported by Ober and associates (28 weeks)," Winslow and Taylor (five months)," and Leff, Welch, and Tasman (six months). 13 Six of our 13 patients with retinal detachment (46.2%) developed this complication within the first two months after capsulotomy. Fastenberg, Schwartz, and Lin 14 described five patients who had a retinal detachment within one month of undergoing capsulotomy. In our study, retinal detachment occurred within six months for nine patients (69.2%) and within one year for 11 patients (84.6%) with this complication. The short interval between capsulotomy and the onset of retinal detachment suggests that the YAG laser plays a causal role in the development of this complication. It is uncertain at present whether this effect is caused by the laser application itself or is a secondary complication of rupturing the posterior capsule. The power required for adequate capsuloto my was not statistically correlated with the occurrence of retinal detachment. The mean total power used was 99.2 m] for patients who did not develop retinal detachment. This figure is similar to the mean total energy used by Keates, Steinert, and Puliafito (101 ml);' and substantially lower than that used by Stark and associates (140 mJ).2 The incidence of retinal detachment in these two studies was 0.4% and 0.5%, respectively. Hence, the applied power of the laser beam does not appear to playa causal role in the development of retinal detachment. Male gender was significantly correlated to

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Retinal Detachment After YAG Capsulotomy

the development of retinal detachment for all patients undergoing YAG capsulotomy, while younger age at capsulotomy demonstrated a trend toward significant correlation with this complication. Smith and associates" found that male gender and younger age were significantly related to an increased postoperative risk of retinal detachment in patients undergoing extracapsular cataract extraction with posterior chamber lens implantation. An independent evaluation of the subgroup of patients in our study with posterior chamber lenses yielded a significant correlation between younger age at capsulotomy and an increased incidence of retinal detachment. However, no such correlation was noted for male gender in this subgroup. Although axial myopia (:::=25.00 mm), lattice degeneration, and a history of retinal detachment in the fellow eye have previously been identified as increasing the risk of postoperative retinal detachment.v'v'v" we did not find these traits to be risk factors in the development of retinal detachment in patients with posterior chamber lenses. However, Significantly more men with axial myopia in this subgroup had retinal detachment after capsulotomy. Moreover, significantly more of the patients who subsequently developed retinal detachment showed one or more of these three ocular diseases. The correlation was even stronger between men with one or more of these traits and the incidence of retinal detachment after capsulotomy. Hence, younger men with axial myopia, lattice degeneration, or a history of retinal detachment in the fellow eye, should be considered at higher risk for subsequent retinal detachment than the general population of patients undergoing YAG capsulotomy. No significant correlation was found between retinal detachment and the method of extracapsular cataract surgery, the total power used for capsulotomy, or the interval between intraocular lens implantation and YAG capsulotomy. In addition to the critical risk factors for retinal detachment after YAG capsulotomy already discussed, there were other preexisting ocular diseases in the 13 eyes that developed retinal detachment which were not analyzed. Three eyes had an old vitreous hemorrhage, three eyes had a history of retinal detachment, two eyes had chronic open-angle glaucoma, one eye had peripheral diabetic retinopathy, one eye had senile macular degeneration, and one eye had cytomegalovirus retinitis. All of these conditions were present before cap-

535

sulotomy and may have played a role in the subsequent development of retinal detachment. Predisposing risk factors for retinal detachment should be taken into account when evaluating a candidate for YAG laser posterior capsulotomy. Physicians need to identify those patients at risk for retinal detachment preoperatively and should be conservative in their recommendation of YAG laser posterior capsulotomy for these patients. For all patients undergoing YAG capsulotomy, the importance of performing preoperative and postoperative ophthalmoscopy must be stressed. This is especially critical in the first year after capsulotomy, when most of the retinal detachments occur.

References 1. Keates, R. H., Steinert, R. F., and Puliafito, C. A.: Long-term follow-up of Nd:YAG laser posterior capsulotomy. Am. J. Intraocul. Implant Soc. 10:164, 1984. 2. Stark, W. J., Worthen, D., Holladay, J. T., and Murray, G.: Neodymium:YAG lasers. An FDA report. Ophthalmology 92:209, 1985. 3. Aron-Rosa, D., Aron, J. J., and Cohn, H. c. Use of a pulsed picosecond Nd-YAG laser in 6,664 cases. Am. J. Intraocul. Implant Soc. 10:35, 1984. 4. Shah, G. R., Gills, J. P., Durham, D. G., and Ausmus, W. H.: Three thousand YAG lasers in posterior capsulotomies. An analysis of complications and comparisons to polishing and surgical discission. Ophthalmic Surg. 17:473, 1986. 5. Johnson, S. H., Kratz, R. P., and Olson, P. F.: Clinical experience with the Nd:YAG laser. Am. J. Intraocul. Implant Soc. 10:452, 1984. 6. Ficker, L. A., Capon, M. R. C.; Mellerio, J., and Cooling, R. J.: Retinal detachment following Nd:YAG posterior capsulotomy. Eye 1:86, 1987. 7. Lindstrom, R. L., and Harris, W. 5.: Management of the posterior capsule following posterior chamber lens implantation. Am. J. Intraocul. Implant Soc. 6:255, 1980. 8. Coonan, P., Fung, W. E., Webster, R. G., Allen, A. W., and Abbott, R. L.: The incidence of retinal detachment following extracapsular cataract extraction. A ten-year study. Ophthalmology 92:1096, 1985. 9. Hurite, F. G., SOH, E. M., and Everett, W. G.: The incidence of retinal detachment following phacoemulsification. Ophthalmology 86:2004, 1979. 10. Fung, W. E., Coonan, P. c.. and Ho, B. T.: Incidence of retinal detachments following extracapsular cataract extraction. A prospective study. Retina 1:232,1981. 11. Ober, R. R., Wilkinson, C. P., Fiore, J. V., Jr.,

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and Maggiano, J. M.: Rhegmatogenous retinal detachments after neodymium-YAG laser capsulotomy in phakic and pseudophakic eyes. Am. J. Ophthalmol. 101:81, 1986. 12. Winslow, R. L., and Taylor, B. c.. Retinal complications following YAG laser capsulotomy. Ophthalmology 92:785, 1985. 13. Leff, L. R., Welch, J. c.. and Tasman, W.: Rhegmatogenous retinal detachment after YAG laser posterior capsulotomy. Ophthalmology 94:1222, 1987.

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14. Fastenberg, D. M., Schwartz, P. L., and Lin, H. Z.: Retinal detachment following neodymiumYAG laser capsulotomy. Am. J. Ophthalmol. 97:288, 1984. 15. Smith, P. W., Stark, W. J., Maumenee, A. E., Enger, C. E., Michels, R. G., Glaser, B. M., and Bonham, R. D.: Retinal detachment after extracapsular cataract extraction with posterior chamber intraocular lens. Ophthalmology 94:495, 1987.

OPHTHALMIC MINIATURE

Another illness that played havoc among the human cargoes crowded in the holds of slave ships was the dreaded disease ophthalmia. This disease, once started, spread so fast and with such frightening consequences that in a matter of days whole cargoes of Negroes went blind. One of the most dramatic cases of an ophthalmic epidemic encompassing an entire ship, slaves, crewmen, and officers, occurred aboard the French slaver, Le Rodeur, in the year 1819. The epic tale was recorded by a youthful passenger, a twelve-year-old boy, in a diary intended for his mother. So tragic and heartrending was his poignant tale that it later received Widespread attention. Isidor Paiewonsky, Eyewitness Accounts of Slavery in the Danish West Indies Privately printed by the author, 1987, p. 82