- Email: [email protected]
Ultraviolet-absorbing intraocular lens versus non-UV-absorbing intraocular lens: Comparison of angiographic cystoid macular edema
Ultraviolet-absorbing intraocular lens versus non-UV-absorbing intraocular lens: Comparison of angiographic cystoid macular edema Mari Komatsu, M.D., Sadao Kanagami , F.O.P.S., Kimiya Shimizu, M.D.
ABSTRACT We compared the incidence of angiographic cy toid macular edema (CME) in eyes with ultraviolet (UV}-ab orbing intraocular lenses (IOLs) with that in eyes with non-UV-ab orbing IOL . Fifty-6ve bilateral pseudophakic patients received a UV-ab orbing IOL in one eye and a non-UV-ab orbing IOL in the fellow eye. All ca es were implanted with po terior chamber len e following exh'acap ular cataract extraction. Fluorescein angiograph for CME was performed at lea t ix month postoperatively (average 20.0 month ). There wa no tatistically igni6cant difference in vi ual acuity or in the incidence of CME. Key Words: angiographic c stoid macular d rna non-UV-ab orbing intraocular In , UV-ab 'orbin intraocular I ns
The use of ultraviolet (UV)-absorbing intraocular lenses (IOLs) has become popular in recent years to protect the retina from the hazards of chronic UV light exposure. l However, only a few reports explore the clinical difference between UV-absorbing IOLs and non-UV-absorbingIOLs(D.J. McIntyre, M.D., "Statistics on CME and UV Lenses/' American-International IOL Congress, Boston, April 1985).2,3 Furthermore, questions about their long-term stability have been reported (P.E. Bath, M.D. , "Injection-molded UVblocking IOLs Show Power Dimensional Changes in Age-Acceleration Test," Ocular Surgery News, March 1, 1988, pp 1, 25).4,5 Clinically the harmful effects ascribed to UV light are cystoid macular edema (CME), macular degeneration, erythropsia, and color distortion. Ofthese, CME is considered the easiest to detect objectively and repeatedly. In a previous study,3 it was reported that there was no difference in the incidence of clinical CME in eyes implanted with UV-absorbing IOLs and in those implanted with non- UV-absorbing IOLs after 9.6 months average follow-up. In this study, we retrospectively selected bilateral pseudophakic patients
who had a UV-absorbing IOL in one eye and a non-UVabsorbing IOL in the fellow eye so that patients' personal factors were excluded. To exclude surgical influences and to detect subclinical CME, each patient's fluorescein angiogram was examined after a follow-up of six months or more.
MATERIALS AND METHODS We selected bilateral pseudophakic patients who met the following criteria: (1) One eye had been implanted with a posterior chamber UV-absorbing IOL and the other eye with a posterior chamber non-UVabsorbing IOL after extracapsular cataract ex't raction; (2) there were no pre-existing localized or generalized complications; (3) there were no serious complications during the operation; (4) the follow-up was longer than six months; (5) conditions were adequate to obtain a satisfactory fluorescein angiogram , mydriasis was achieved, and the posterior capsule opacification was minimal; (6) there were no conditions that might induce CME, such as decentration of the IOL or posterior synechias adhering to the IOL. If a posterior caps ulotomy had been done, fluorescein angiography
From the Musashino Red Cross Hospital , Tokyo, Japan. Presented in part at the Symposium on Cataract, IOL and Refractive Surgery, Los Angeles, March 1988. Reprint requests to Kimiya Shimizu , M.D ., Department of Ophthalmology, Musashino Red Cross Hospital , 1-26, Kyo/mall, Musasliino , Tokyo , Japan. 654
J CATARACT
REFRACT SURG-VOL 15, NOVEMBER 1989
was postponed more than six months after the date of capsulotomy. Fifty-five patients were enrolled. Thirty-four were female (61.8%) and 21 were male (38.2%). Ages ranged from 38 to 79 years (average 63.6 years). Postoperative follow-up times were from seven to 40 months (average 22 .6 months) for eyes with UV-absorbing IOLs and seven to 45 months (average 18.3 months) for eyes with non-UV-absorbing IOLs. Neodymium:YAG laser capsulotomy has been done in six eyes with UV-absorbing IOLs and in eight eyes with non-UV-absorbing IOLs. The examination included corrected visual acuity, examination of the retina by slitlamp microscopy using the three-mirror contact lens, and fluorescein angiography. All operations were performed by the same surgeon (K.S.). Postoperative observations were performed by another physician (M.K .) and fluorescein angiography by a third (S.K.). The third physician evaluated the presence or absence of CME while taking photographs and later on the basis of the negatives without knowing the type of IOL. The final evaluation was made from the photographs taken from ten to 15 minutes after the injection. The UV-absorbing IOLs used were from Cilco, ORC, Coburn, and IOLAB. Non-UV-absorbing IOLs were from Cilco, Intermedics, Pharmacia, Precision Cosmet, and HOYA. The refractive power of the IOLs ranged from 10.0 diopters (D) to 23.0 D, and the difference between the two eyes of each patient was smaller than 1.5 D. Cataract extractions were performed using phacoemulsification or extracapsular cataract extraction. RESULTS At the latest follow-up visit, 85.5% of patients had achieved corrected visual acuities of 20/20 or better in Table 1. Visual acuity results. UV-IOL
Non-UV-IOL
20/15-20/20
Visual Acuity
47/55 (85.5%)
46/55 (83.7%)
20/20-20/30
8/55 (14.5%)
9/55 (16.3%)
eyes implanted with UV-absorbing IOLs; 83.7% had achieved 20/20 or better in eyes implanted with nonUV-absorbing IOLs; all eyes achieved better than 20/30 (Table 1). There was no significant difference in the visual acuity outcome between UV-absorbing IOLs and non- UV-absorbing IOLs. Cystoid macular edema was detected by fluorescein angiography in three eyes with non- UV-absorbing IOLs (3/55; 5.5%) and in no eyes with UV-absorbing IOLs (0/55). Although there was no significant difference between UV-absorbing IOLs and non-UVabsorbing IOLs statistically (X2 test, P > .05), CME was more frequent in eyes with non- UV-absorbing IOLs. Table 2 shows the sex, age, IOL refractive power, procedure of cataract removal, observation period, and visual acuity of the patients who were diagnosed as having CME on the basis of fluorescein angiography. Figures 1, 2, and 3 show the fluorescein angiographies. Cystoid macular edema occurred only in eyes with non-UV-absorbing IOLs. All cases were female. Cataract removal had been with phacoemulsification and the IOLs were fixated in the capsular bag. Posterior capsules remained intact in all cases. Corrected visual acuity was good and there were no abnormal findings by ophthalmoscopy or slitlamp microscopy. Difference in IOL refractive power between the right and left eyes was less than 0.5 D in each case. Only Case 2 had a history of inflammation such as fibrinoid reaction and CME in the early postoperative period in both eyes. DISCUSSION To discuss the need for UV-absorbing chromophores in IOL substances is to compare the advantages and disadvantages of UV-absorbing IOLs. The theoretical advantage of a UV-absorbing IOL is that it minimizes the hazards of UV light to ocular tissues, especially to the retina. The disadvantage is that the UV-absorbing chromophore is not completely stable and the poly(methyl methacrylate) (PMMA) may become fragile from Nd:YAG laser irradiation since the molecular weight is lower . if a UV-absorbing chromophore is added. 5 To determine whether UV-absorbing IOLs
Table 2. Cases with angiographic CME. Case Number
Age/Sex
IOL
IOL Power (D)
Phacoemulsification or Planned ECCE
Follow-Up (months)
Visual Acuity
1
66/F
UV
17.5
Phacoe mulsification
27
20/20
2
70/F
3
68/F
Non-UV
18.0
Phacoemulsification
8
20/15
UV
20.5
Phacoemulsification
35
20/25
Non-UV
21.0
Phacoemulsi fication
45
20/20
UV
20.0
Phacoemulsification
31
20/20
Non-UV
20 .0
Phacoemulsification
16
20/20
J CATARACT REFRACT
SURG- VOL 15. NOVE MBER 1989
CME
+ + + 655
Fig. 1.
(Komatsu) Fluorescein angiogram of Case 1. Left: The right eye with non-UV-IOL has CME. Right: The left eye with UV-IOL is normal.
could suppress the hazards from UV light, we compared the incidence ofCME in UV-absorbing IOLs and non- UV-absorbing IOLs. Cystoid macular edema was seen in three eyes with non- UV-absorbing IOLs and in no eyes with UV-absorbing IOLs, but statistically there was no significant difference. Three factors should be considered to explain the results of this study. First, the number of patients in each study group was small and therefore a statistically significant difference was not anticipated, although it is questionable whether a greater number of patients would yield different results. Second, the UV absorption effect of current UV-absorbing IOLs was not sufficient. Figure 4 shows the transmittance oflight in a 54-year-old normal human crystalline lens, in UVabsorbing PMMA, and in non-U V-absorbing PMMA.l The human crystalline lens absorbs almost 100% at 395 nm and more than 95% at 400 nm in the UV-light range and about 50% at 450 nm in visible light. Current
UV-absorbing PMMA can absorb UV light well only at shorter wavelengths and both the absorbing range and absorbing rate are very small compared to those of human lenses (P.S. O 'Connor, M .D., T.J. Tredici, M .D., P.T. O'Conner, M .D., "UV-Absorption by Intraocular Lenses, " American Academy of Ophthalmology annual meeting, Dallas, 1987). Ultraviolet energy is concentrated in longer wavelengths, especially between 380 nm and 400 nm, and while the shorter wavelength of visible light is thought to be harmful,6 it seems that the current UV-absorbing PMMA is not sufficient in terms of absorbing range or absorbing rate (P.S. O'Connor, M.D., T.J. Tredici , M.D., P.T. O'Conner, M .D., "UV-Absorption by Intraocular Lenses, " American Academy of Ophthalmology annual meeting, Dallas, 1987). The third factor in explaining the results of this study is that the observation period is short. We waited at least six months postoperatively (seven to 45 months,
Fig. 2. (Komatsu) Fluorescein angiogram of Case 2. Left: The right eye with non-UV-IOL has CME. Right: The left eye with UV-IOL is normal. 656
J CATARACT REFRACT SURG-VOL
15, NOVEMBER 1989
Fig. 3. (Komatsu) Fluorescein angiogram of Case 3. LRft: The right eye with non-UV-IOL has CME. Right: The left eye with UV-IOL is normal.
" 100
w
oz c(
~
:a: 50 z
en
~ .....
HUMAN LENS
(S4YR.)
r--::::;..."""
o
320
500
400 WAVELENGTH ( nm )
Fig. 4. (Komatsu) Comparison of transmission of light in non-UVPMMA, UV-PMMA, and normal 54-year old human crystalline lens (adapted from Lindstrom and Doddil).
average 20.0 months) to avoid surgical influences and postoperative inflammatory responses. The angiographic CME noticed in Case 2 was not necessarily the result ofUV light. Moderate fibrinoid reaction and CME were noticed in an early postoperative period in both eyes. Angiographic CME probably reflected the prolonged inflammatory reaction in these eyes. There-
J CATARACT
fore, to discuss the chronic toxicity ofUV light, a much longer observation period is necessary. The long-term stability of a UV-absorbing chromophore or UV-absorbing substance in the human eye must also be considered. Ultraviolet-absorbing PMMA is lower in molecular weight whether the UV-absorbing material is added in a chemically bonded system or in an additive system: UV-absorbing IOLs can be damaged more easily by N d: YAG laser irradiation than nonUV-absorbing IOLs.5 In conclusion, we must continue to follow more cases over longer periods to evaluate the effectiveness of UV-absorbing material in IOLs. REFERENCES 1. Lindstrom RL, Doddi N: Ultraviolet light absorption in intraocular lenses. ] Cataract Refract Surg 12:285-289, 1986 2. KraffMC, Sanders DR, Jampol LM, Lieberman HL: Effect of an ultraviolet-filtering intraocular lens on cystoid macular edema. Ophthalmology 92:366-369, 1985 3. Kinoshita N, Shimizu K: Clinical evaluation of ultravioletabsorbing intraocular lenses. Rinsho Ganka (Jap J Clin Ophthalmol) 41:145-149,1987 4. Clayman HM: Ultraviolet-absorbing chromophores: Chemical and ultraviolet transmission characteristics. ] Cataract Refract Surg 12:529-532, 1986 5. Shimizu K, Sakai H: Physical characteristics of various intraocular lenses. ] Cataract Refract Surg 13:151-156, 1987 6. Ham wr Jr, Mueller HA, Ruffolo JJ Jr, Guerry DIll, et al: Action spectrum for retinal injury from near-ultraviolet radiation in the aphakic monkey. Am] Ophthalmol93:299-306, 1982
REFRACT SURG-VOL 15, NOVEMBER 1989
657
ABSTRACT We compared the incidence of angiographic cy toid macular edema (CME) in eyes with ultraviolet (UV}-ab orbing intraocular lenses (IOLs) with that in eyes with non-UV-ab orbing IOL . Fifty-6ve bilateral pseudophakic patients received a UV-ab orbing IOL in one eye and a non-UV-ab orbing IOL in the fellow eye. All ca es were implanted with po terior chamber len e following exh'acap ular cataract extraction. Fluorescein angiograph for CME was performed at lea t ix month postoperatively (average 20.0 month ). There wa no tatistically igni6cant difference in vi ual acuity or in the incidence of CME. Key Words: angiographic c stoid macular d rna non-UV-ab orbing intraocular In , UV-ab 'orbin intraocular I ns
The use of ultraviolet (UV)-absorbing intraocular lenses (IOLs) has become popular in recent years to protect the retina from the hazards of chronic UV light exposure. l However, only a few reports explore the clinical difference between UV-absorbing IOLs and non-UV-absorbingIOLs(D.J. McIntyre, M.D., "Statistics on CME and UV Lenses/' American-International IOL Congress, Boston, April 1985).2,3 Furthermore, questions about their long-term stability have been reported (P.E. Bath, M.D. , "Injection-molded UVblocking IOLs Show Power Dimensional Changes in Age-Acceleration Test," Ocular Surgery News, March 1, 1988, pp 1, 25).4,5 Clinically the harmful effects ascribed to UV light are cystoid macular edema (CME), macular degeneration, erythropsia, and color distortion. Ofthese, CME is considered the easiest to detect objectively and repeatedly. In a previous study,3 it was reported that there was no difference in the incidence of clinical CME in eyes implanted with UV-absorbing IOLs and in those implanted with non- UV-absorbing IOLs after 9.6 months average follow-up. In this study, we retrospectively selected bilateral pseudophakic patients
who had a UV-absorbing IOL in one eye and a non-UVabsorbing IOL in the fellow eye so that patients' personal factors were excluded. To exclude surgical influences and to detect subclinical CME, each patient's fluorescein angiogram was examined after a follow-up of six months or more.
MATERIALS AND METHODS We selected bilateral pseudophakic patients who met the following criteria: (1) One eye had been implanted with a posterior chamber UV-absorbing IOL and the other eye with a posterior chamber non-UVabsorbing IOL after extracapsular cataract ex't raction; (2) there were no pre-existing localized or generalized complications; (3) there were no serious complications during the operation; (4) the follow-up was longer than six months; (5) conditions were adequate to obtain a satisfactory fluorescein angiogram , mydriasis was achieved, and the posterior capsule opacification was minimal; (6) there were no conditions that might induce CME, such as decentration of the IOL or posterior synechias adhering to the IOL. If a posterior caps ulotomy had been done, fluorescein angiography
From the Musashino Red Cross Hospital , Tokyo, Japan. Presented in part at the Symposium on Cataract, IOL and Refractive Surgery, Los Angeles, March 1988. Reprint requests to Kimiya Shimizu , M.D ., Department of Ophthalmology, Musashino Red Cross Hospital , 1-26, Kyo/mall, Musasliino , Tokyo , Japan. 654
J CATARACT
REFRACT SURG-VOL 15, NOVEMBER 1989
was postponed more than six months after the date of capsulotomy. Fifty-five patients were enrolled. Thirty-four were female (61.8%) and 21 were male (38.2%). Ages ranged from 38 to 79 years (average 63.6 years). Postoperative follow-up times were from seven to 40 months (average 22 .6 months) for eyes with UV-absorbing IOLs and seven to 45 months (average 18.3 months) for eyes with non-UV-absorbing IOLs. Neodymium:YAG laser capsulotomy has been done in six eyes with UV-absorbing IOLs and in eight eyes with non-UV-absorbing IOLs. The examination included corrected visual acuity, examination of the retina by slitlamp microscopy using the three-mirror contact lens, and fluorescein angiography. All operations were performed by the same surgeon (K.S.). Postoperative observations were performed by another physician (M.K .) and fluorescein angiography by a third (S.K.). The third physician evaluated the presence or absence of CME while taking photographs and later on the basis of the negatives without knowing the type of IOL. The final evaluation was made from the photographs taken from ten to 15 minutes after the injection. The UV-absorbing IOLs used were from Cilco, ORC, Coburn, and IOLAB. Non-UV-absorbing IOLs were from Cilco, Intermedics, Pharmacia, Precision Cosmet, and HOYA. The refractive power of the IOLs ranged from 10.0 diopters (D) to 23.0 D, and the difference between the two eyes of each patient was smaller than 1.5 D. Cataract extractions were performed using phacoemulsification or extracapsular cataract extraction. RESULTS At the latest follow-up visit, 85.5% of patients had achieved corrected visual acuities of 20/20 or better in Table 1. Visual acuity results. UV-IOL
Non-UV-IOL
20/15-20/20
Visual Acuity
47/55 (85.5%)
46/55 (83.7%)
20/20-20/30
8/55 (14.5%)
9/55 (16.3%)
eyes implanted with UV-absorbing IOLs; 83.7% had achieved 20/20 or better in eyes implanted with nonUV-absorbing IOLs; all eyes achieved better than 20/30 (Table 1). There was no significant difference in the visual acuity outcome between UV-absorbing IOLs and non- UV-absorbing IOLs. Cystoid macular edema was detected by fluorescein angiography in three eyes with non- UV-absorbing IOLs (3/55; 5.5%) and in no eyes with UV-absorbing IOLs (0/55). Although there was no significant difference between UV-absorbing IOLs and non-UVabsorbing IOLs statistically (X2 test, P > .05), CME was more frequent in eyes with non- UV-absorbing IOLs. Table 2 shows the sex, age, IOL refractive power, procedure of cataract removal, observation period, and visual acuity of the patients who were diagnosed as having CME on the basis of fluorescein angiography. Figures 1, 2, and 3 show the fluorescein angiographies. Cystoid macular edema occurred only in eyes with non-UV-absorbing IOLs. All cases were female. Cataract removal had been with phacoemulsification and the IOLs were fixated in the capsular bag. Posterior capsules remained intact in all cases. Corrected visual acuity was good and there were no abnormal findings by ophthalmoscopy or slitlamp microscopy. Difference in IOL refractive power between the right and left eyes was less than 0.5 D in each case. Only Case 2 had a history of inflammation such as fibrinoid reaction and CME in the early postoperative period in both eyes. DISCUSSION To discuss the need for UV-absorbing chromophores in IOL substances is to compare the advantages and disadvantages of UV-absorbing IOLs. The theoretical advantage of a UV-absorbing IOL is that it minimizes the hazards of UV light to ocular tissues, especially to the retina. The disadvantage is that the UV-absorbing chromophore is not completely stable and the poly(methyl methacrylate) (PMMA) may become fragile from Nd:YAG laser irradiation since the molecular weight is lower . if a UV-absorbing chromophore is added. 5 To determine whether UV-absorbing IOLs
Table 2. Cases with angiographic CME. Case Number
Age/Sex
IOL
IOL Power (D)
Phacoemulsification or Planned ECCE
Follow-Up (months)
Visual Acuity
1
66/F
UV
17.5
Phacoe mulsification
27
20/20
2
70/F
3
68/F
Non-UV
18.0
Phacoemulsification
8
20/15
UV
20.5
Phacoemulsification
35
20/25
Non-UV
21.0
Phacoemulsi fication
45
20/20
UV
20.0
Phacoemulsification
31
20/20
Non-UV
20 .0
Phacoemulsification
16
20/20
J CATARACT REFRACT
SURG- VOL 15. NOVE MBER 1989
CME
+ + + 655
Fig. 1.
(Komatsu) Fluorescein angiogram of Case 1. Left: The right eye with non-UV-IOL has CME. Right: The left eye with UV-IOL is normal.
could suppress the hazards from UV light, we compared the incidence ofCME in UV-absorbing IOLs and non- UV-absorbing IOLs. Cystoid macular edema was seen in three eyes with non- UV-absorbing IOLs and in no eyes with UV-absorbing IOLs, but statistically there was no significant difference. Three factors should be considered to explain the results of this study. First, the number of patients in each study group was small and therefore a statistically significant difference was not anticipated, although it is questionable whether a greater number of patients would yield different results. Second, the UV absorption effect of current UV-absorbing IOLs was not sufficient. Figure 4 shows the transmittance oflight in a 54-year-old normal human crystalline lens, in UVabsorbing PMMA, and in non-U V-absorbing PMMA.l The human crystalline lens absorbs almost 100% at 395 nm and more than 95% at 400 nm in the UV-light range and about 50% at 450 nm in visible light. Current
UV-absorbing PMMA can absorb UV light well only at shorter wavelengths and both the absorbing range and absorbing rate are very small compared to those of human lenses (P.S. O 'Connor, M .D., T.J. Tredici, M .D., P.T. O'Conner, M .D., "UV-Absorption by Intraocular Lenses, " American Academy of Ophthalmology annual meeting, Dallas, 1987). Ultraviolet energy is concentrated in longer wavelengths, especially between 380 nm and 400 nm, and while the shorter wavelength of visible light is thought to be harmful,6 it seems that the current UV-absorbing PMMA is not sufficient in terms of absorbing range or absorbing rate (P.S. O'Connor, M.D., T.J. Tredici , M.D., P.T. O'Conner, M .D., "UV-Absorption by Intraocular Lenses, " American Academy of Ophthalmology annual meeting, Dallas, 1987). The third factor in explaining the results of this study is that the observation period is short. We waited at least six months postoperatively (seven to 45 months,
Fig. 2. (Komatsu) Fluorescein angiogram of Case 2. Left: The right eye with non-UV-IOL has CME. Right: The left eye with UV-IOL is normal. 656
J CATARACT REFRACT SURG-VOL
15, NOVEMBER 1989
Fig. 3. (Komatsu) Fluorescein angiogram of Case 3. LRft: The right eye with non-UV-IOL has CME. Right: The left eye with UV-IOL is normal.
" 100
w
oz c(
~
:a: 50 z
en
~ .....
HUMAN LENS
(S4YR.)
r--::::;..."""
o
320
500
400 WAVELENGTH ( nm )
Fig. 4. (Komatsu) Comparison of transmission of light in non-UVPMMA, UV-PMMA, and normal 54-year old human crystalline lens (adapted from Lindstrom and Doddil).
average 20.0 months) to avoid surgical influences and postoperative inflammatory responses. The angiographic CME noticed in Case 2 was not necessarily the result ofUV light. Moderate fibrinoid reaction and CME were noticed in an early postoperative period in both eyes. Angiographic CME probably reflected the prolonged inflammatory reaction in these eyes. There-
J CATARACT
fore, to discuss the chronic toxicity ofUV light, a much longer observation period is necessary. The long-term stability of a UV-absorbing chromophore or UV-absorbing substance in the human eye must also be considered. Ultraviolet-absorbing PMMA is lower in molecular weight whether the UV-absorbing material is added in a chemically bonded system or in an additive system: UV-absorbing IOLs can be damaged more easily by N d: YAG laser irradiation than nonUV-absorbing IOLs.5 In conclusion, we must continue to follow more cases over longer periods to evaluate the effectiveness of UV-absorbing material in IOLs. REFERENCES 1. Lindstrom RL, Doddi N: Ultraviolet light absorption in intraocular lenses. ] Cataract Refract Surg 12:285-289, 1986 2. KraffMC, Sanders DR, Jampol LM, Lieberman HL: Effect of an ultraviolet-filtering intraocular lens on cystoid macular edema. Ophthalmology 92:366-369, 1985 3. Kinoshita N, Shimizu K: Clinical evaluation of ultravioletabsorbing intraocular lenses. Rinsho Ganka (Jap J Clin Ophthalmol) 41:145-149,1987 4. Clayman HM: Ultraviolet-absorbing chromophores: Chemical and ultraviolet transmission characteristics. ] Cataract Refract Surg 12:529-532, 1986 5. Shimizu K, Sakai H: Physical characteristics of various intraocular lenses. ] Cataract Refract Surg 13:151-156, 1987 6. Ham wr Jr, Mueller HA, Ruffolo JJ Jr, Guerry DIll, et al: Action spectrum for retinal injury from near-ultraviolet radiation in the aphakic monkey. Am] Ophthalmol93:299-306, 1982
REFRACT SURG-VOL 15, NOVEMBER 1989
657