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Posterior capsule striae
Posterior capsule striae Abhay R. Vasavada, MS, FRCS, Rupal H. Trivedi, MS ABSTRACT Purpose: To find the incidence, contributing factors, outcomes, and clinical impact of intraoperative posterior capsule striae. Setting: Iladevi Cataract & IOL Research Centre, Ahmedabad, India. Methods: In a prospective study, 100 consecutive eyes had phacoemulsification and intraocular lens (IOL) (AcrySof姞 MA30BA) implantation. The presence of striae was noted at the end of the operation, and factors contributing to their development were identified. Follow-up was done at regular intervals, and the clinical impact of striae on patients’ vision was evaluated. Results: Striae were observed in 56 eyes (Group 1) but were absent in 44 (Group 2). Mean age in Group 1 was 65.96 years ⫾ 9.15 (SD) and in Group 2, 59.20 ⫾ 10.36 years (P ⫽ .0012). Mean axial lengths were 23.47 ⫾ 1.63 and 24.12 ⫾ 1.49 mm, respectively (P ⫽ .0419). Average lens thickness was greater in Group 1 (4.50 ⫾ 0.43 mm) than in Group 2 (4.13 ⫾ 0.41 mm) (P ⫽ .0001). The sex of patient, capsulorhexis size and centration, grade of cataract hardness, scleral rigidity, and IOL centration were not found to contribute to striae development. The striae disappeared by 5 months postoperatively and did not show a positive Maddox rod phenomenon. Conclusion: Intraoperative striae observed in many patients were associated with relatively older age, greater lens thickness, and shorter axial length. The striae eventually disappeared and had no effect on vision. J Cataract Refract Surg 1999; 25:1527–1531 © 1999 ASCRS and ESCRS
P
osterior capsule striae are often observed during surgery after an intraocular lens (IOL) is placed in the capsular bag. Intraoperative striae1 are seen as broad undulations, mainly on the central posterior capsule, and appear as single or multiple folds on the axis joining the apex of the genus of the haptics (Figures 1 and 2). These arise as a result of disparity in size between the IOL and capsular bag. Wrinkling may occur postoperatively after
IOL implantation in the capsular bag. This wrinkling is recognized as a type of posterior capsule opacification (PCO) resulting from fibrosis.2 To our knowledge, the occurrence and course of these intraoperative capsule striae have not been reported. This study was therefore designed to find the incidence of intraoperative striae, identify the factors contributing to their development, follow their course, and examine their clinical impact on the patient.
Accepted for publication May 14, 1999. From the Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India. Presented at the Symposium on Cataract, IOL and Refractive Surgery, San Diego, California, USA, April 1998. Reprint requests to Abhay R. Vasavada, MS, FRCS, Iladevi Cataract & IOL Research Centre, Gurukul Road, Memnagar, Ahmedabad 380 052, India. © 1999 ASCRS and ESCRS Published by Elsevier Science Inc.
Materials and Methods In a prospective, controlled, double-masked study, 100 consecutive eyes were implanted with a modified C-loop IOL with an overall diameter of 12.5 mm, a 5.5 mm optic diameter, and 5 degree angled haptics (AcrySof威 MA3OBA). The in-the-bag implantations 0886-3350/99/$–see front matter PII S0886-3350(99)00197-2
POSTERIOR CAPSULE STRIAE
Figure 1. (Vasavada) Intraoperative striae.
Figure 2. (Vasavada) Multiple striae. Note the residual lens fibers firmly adherent to the posterior capsule in an eye with a mature cataract.
were done in April 1997 by 1 surgeon (A.R.V.). Exclusion criteria were incomplete anterior capsulorhexis, posterior capsule tear, and previous eye surgery. The patients’ axial length and lens thickness were measured with a Humphrey ultrasonic biometer. Intraoperatively, the capsulorhexis size and centricity, IOL centration, and the surgeon’s subjective impression of the nucleus’ grade of hardness and scleral rigidity were noted. The condition of the posterior capsule (residual lens fibers and residual plaque) was also observed. Approximately 90% of the viscoelastic agent was removed in all eyes. At the end of surgery, absence or presence of striae was recorded. When striae were present, their number, sharpness, and location were also noted. Follow-up was done of patients in whom striae were present at the end of surgery at 1 and 7 days and 1, 3, and 5 months postoperatively. In eyes in which striae persisted beyond 1 month, the Maddox rod phenomenon was evaluated. The operated eye was covered, a Maddox rod was placed in front of the normal eye, and the patient was asked to see a single light source. Then, the patient was asked to cover the normal eye, and the test was repeated on the operated eye. Statistical analysis was done using the chi-square test for independence and the Student t test.
Results Striae were observed in 56 eyes (Group 1) but absent in 44 (Group 2). The mean patient age was 65.96 years ⫾ 9.15 (SD) in Group 1 and 59.20 ⫾ 10.36 years 1528
in Group 2. The difference was significant (P ⫽ .0012). Of male patients, 50.8% developed striae while 65.7% of female patients developed them. This difference was not statistically significant (P ⫽ .15). Average axial length in Group 1 was 23.47 ⫾ 1.63 mm and in Group 2, 24.12 ⫾ 1.49 mm (P ⫽ .0419). Seven of 8 eyes with an axial length of 22.0 mm or less and 4 of 10 eyes with an axial length of 26.5 mm or more developed striae (P ⫽ .04). Mean lens thickness was greater in Group 1 (4.50 ⫾ 0.43 mm) than in Group 2 (4.13 ⫾ 0.41 mm) (P ⫽ .0001). Striae formation was observed in all eyes with a lens thickness of 5.0 mm or more (n ⫽ 12) (P ⫽ .0018). Mean capsulorhexis size was 5.55 mm in Group 1 and 5.60 mm in Group 2 (P ⫽ .07). In Group 1, 89.20% had a central capsulorhexis and in Group 2, 86.36% (P ⫽ .53). The grade of cataract was judged to be hard (grade 5) in 10 eyes (58.82%) in Group 1 and 7 eyes (41.18%) in Group 2 (P ⫽ .79). Rigidity was judged to be low in 12.50% and 18.18% of eyes, respectively (P ⫽ .4). The IOL was geometrically decentered in 2 eyes intraoperatively, 1 in each group. The posterior capsule was clear in 43 eyes (76.78%) in Group 1 and in 25 eyes (56.81%) in Group 2. Residual posterior capsule plaque was noted in 5 and 3 eyes, respectively. In Group 1, residual lens fibers were found in 14 eyes and in Group 2, 16 eyes. In all eyes, intraoperative striae were present in the direction of the apex of the genus of haptics. In 44 eyes (78.57%), striae were judged to be sharp; in 12 eyes (21.43%), they were faint. One stria was found in 9 eyes
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(16.08%), 2 striae in 39 eyes (69.64%), and multiple striae in 8 eyes (14.28%). In 36 eyes (64.30%), striae remained confined behind the IOL optic, while in 20 eyes (35.7%) they extended beyond the optical margin. The striae disappeared in 8 eyes (14.2%) by 1 day, in 22 eyes (39.2%) by 1 week, in 14 eyes (25.0%) by 1 month, and in 7 eyes (12.5%) by 3 months postoperatively. In the remaining eyes, they disappeared by 5 months postoperatively (Figure 3). No patient reported any visual symptom related to these striae. The authors tried to elicit the Maddox rod phenomenon in the patients in whom the striae persisted beyond 1 month. No patient tested positive for phenomenon.
Discussion Posterior capsule striae can arise during surgery or postoperatively. Table 1 describes the salient features of
both types of capsule striae. A small IOL shows unstable fixation because of inadequate arc of contact between the haptics and capsular bag,3 while a large IOL can cause posterior capsule folds.4 These folds or striae are frequently seen during surgery after an IOL is placed in the capsular bag. A good fit reduces the incidence of PCO.5,6 One can recognize a good fit by looking for intraoperative posterior capsule striae. Occurrence of striae denotes distortion of the capsular bag. Striae formation in more than 2 folds, relatively greater sharpness, and an extending outside optic indicate greater disparity in IOL and capsular bag size. It is important to find out whether these striae permanently or temporarily distort the bag. The incidence of intraoperative posterior capsule striae was 56%. This is not surprising with an overall IOL size of 12.5 mm. The possibility of its occurrence increased in older patients; this is probably explained by the loss of
Figure 3. (Vasavada) A: Intraoperative sharp striae extend beyond the optic. Capsulorhexis is marginally outside the optic. B: Same eye 1 week later. No change in striae. C: Same eye 5 months later. The striae have disappeared. Note the fusion of the anterior and posterior capsule behind the optic.
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Table 1. Posterior capsule striae. Characteristic Pathogenesis
Postoperative Type of fibrous PCO
Intraoperative Disparity in size between IOL and capsular bag
Outcome
Permanent
Temporary
Symptoms
Glare; Maddox rod phenomenon
None
Prevention
Good cortical cleanup; several methods to reduce epithelial cell proliferation and fibrosis suggested
Downsizing IOL
Treatment
Neodymium: YAG laser capsulotomy
No treatment required
capsular elasticity with age. Although a relatively larger proportion of women exhibited striae, there was no statistically significant difference from the incidence in men. Eyes with a shorter axial length developed striae more frequently. There was no evidence that eyes with shorter axial lengths have smaller bag sizes. However, it is probable that such eyes have relatively smaller anterior segment and bag sizes. The available range for the AcrySof IOL is from ⫹10 to ⫹30 diopters. Therefore, we could not implant the lens in extremely short or long eyes and could not enroll patients in whom we could have implanted an IOL outside this range. In Group 1, mean lens thickness was significantly greater than in Group 2. The capsular bag probably loses its elasticity with increased lens thickness, a possible explanation for the more frequent striae. The axial length is generally shorter and the lens usually thicker as age increases.7 We have extensive experience with IOL implantation in children and have found the occurence of capsular striae to be extremely low. We believe capsular elasticity is perhaps more important than bag size and axial length in the genesis of posterior capsule striae. We failed to find a correlation between size and centricity of capsulorhexis and intraoperative striae formation. Testing different IOL designs in cadaver eyes, Ta˜na´ and Belmonte,8 found no statistically significant difference between capsulorhexis diameter and capsular bag distension. We expected harder cataracts with greater lens thickness to produce more striae. However, 1530
we found no significant association. Eyes with low scleral rigidity have more collapsible globes; hence, one would expect a higher incidence of striae formation. We again found no significant association. The relationship between myopia and low scleral rigidity is well known, but we have been unable to include very high myopic patients because of nonavailability of an appropriate IOL power. It is difficult to conclude whether IOL decentration would contribute to striae formation, as we had only 2 cases in our series. Intraoperative PCO is frequently noted in our part of the world. Our findings in this study were consistent with those previously reported.9,10 It is logical to speculate that over time, haptic configuration will remodel to a given bag size, making the posterior capsule striae disappear. Capsular elasticity will also be an important contributing factor. In this study, no patient showed striae at 5 months postoperatively. However, we have seen a patient outside the study population in whom striae persisted for much longer (Figure 4). No patient had symptoms attributed to capsule striae. No patient tested positive for the Maddox rod phenomenon. Fine wrinkles in the posterior capsule may not cause this effect.11 We used Humphrey’s ultrasonic biometer with velocities of 1640 m/sec to measure lens thickness. This measure may not be sensitive enough and could limit lens thickness measurement. Capsular bag size varies in different races.12–14 Therefore, IOL manufacturers may consider tests for
Figure 4. (Vasavada) A rare phenonenon: an eye (not in the study) showing persistence of striae 1 year postoperatively. Note the clear posterior capsule behind optic. Elschnig pearls are present outside the optic margin.
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appropriate IOL size in cadaver and patient eyes at various centers worldwide. It would be interesting to study the incidence of striae with different IOL sizes and configurations and the influence of intraoperative striae formation on ultimate PCO formation.
Conclusion In this study, intraoperative posterior capsule striae in many patients were observed. These striae were seen more frequently in older patients and in eyes with a shorter axial length and increased lens thickness. However, the striae were transient and did not bother the patients. Downsizing the AcrySof IOL may reduce the occurrence of intraoperative posterior capsule striae.
References 1. Richter CU, Steinert RF. Neodymium:yttrium-aluminum-garnet laser posterior capsulotomy. In: Steinert RF, ed, Cataract Surgery: Technique, Complications, & Management. Philadelphia, PA, WB Saunders, 1995; 378 –388 2. Apple DJ, Solomon KD, Tetz MR, et al. Posterior capsule opacification. Surv Ophthalmol 1992; 37:73–116 3. Lim SJ, Kang SJ, Kim HB, Apple DJ. Ideal size of an intraocular lens for capsular bag fixation. J Cataract Refract Surg 1998; 24:397– 402 4. Assia El, Apple DJ. Side-view analysis of the lens. II. Positioning of intraocular lenses. Arch Ophthalmol 1992; 110:94 –97
5. Nakazawa M, Ohtsuki K. Apparent accommodation in pseudophakic eyes after implantation of posterior chamber intraocular lenses. Am J Ophthalmol 1983; 96:435– 438 6. Nishi O. Incidence of posterior capsule opacification in eyes with and without posterior chamber intraocular lenses. J Cataract Refract Surg 1986; 12:519 –522 7. Hoffer KJ. Axial dimension of the human cataractous lens. Arch Ophthalmol 1993; 111:914 –918; erratum p 1626 8. Ta˜na´ P, Belmonte J. Experimental study of different intraocular lens designs implanted in the bag after capsulorhexis. J Cataract Refract Surg 1996; 22:1211–1221 9. Vasavada AR, Chauhan H, Shah G. Incidence of posterior capsular plaque in cataract surgery. J Cataract Refract Surg 1997; 23:798 – 802 10. Peng Q, Hennig H, Vasavada AR, Apple DJ. Posterior capsular plaque; a common feature of cataract surgery in the developing world. Am J Ophthalmol 1988; 125:621– 626 11. Holladay JT, Bishop JE, Lewis JW. Diagnosis and treatment of mysterious light streaks seen by patients following extracapsular cataract extraction. Am Intra-Ocular Implant Soc J 1985; 11:21–23 12. Vasavada A, Singh R. Relationship between lens and capsular bag size. J Cataract Refract Surg 1998; 24:547–551 13. Galand A, Bonhomme L, Collee´ M. Direct measurement of the capsular bag. Am Intra-Ocular Implant Soc J 1984; 10:475– 476 14. Assia El, Apple DJ. Side-view analysis of the lens. I. The crystalline lens and the evacuated bag. Arch Ophthalmol 1992; 110:89 –93
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P
osterior capsule striae are often observed during surgery after an intraocular lens (IOL) is placed in the capsular bag. Intraoperative striae1 are seen as broad undulations, mainly on the central posterior capsule, and appear as single or multiple folds on the axis joining the apex of the genus of the haptics (Figures 1 and 2). These arise as a result of disparity in size between the IOL and capsular bag. Wrinkling may occur postoperatively after
IOL implantation in the capsular bag. This wrinkling is recognized as a type of posterior capsule opacification (PCO) resulting from fibrosis.2 To our knowledge, the occurrence and course of these intraoperative capsule striae have not been reported. This study was therefore designed to find the incidence of intraoperative striae, identify the factors contributing to their development, follow their course, and examine their clinical impact on the patient.
Accepted for publication May 14, 1999. From the Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India. Presented at the Symposium on Cataract, IOL and Refractive Surgery, San Diego, California, USA, April 1998. Reprint requests to Abhay R. Vasavada, MS, FRCS, Iladevi Cataract & IOL Research Centre, Gurukul Road, Memnagar, Ahmedabad 380 052, India. © 1999 ASCRS and ESCRS Published by Elsevier Science Inc.
Materials and Methods In a prospective, controlled, double-masked study, 100 consecutive eyes were implanted with a modified C-loop IOL with an overall diameter of 12.5 mm, a 5.5 mm optic diameter, and 5 degree angled haptics (AcrySof威 MA3OBA). The in-the-bag implantations 0886-3350/99/$–see front matter PII S0886-3350(99)00197-2
POSTERIOR CAPSULE STRIAE
Figure 1. (Vasavada) Intraoperative striae.
Figure 2. (Vasavada) Multiple striae. Note the residual lens fibers firmly adherent to the posterior capsule in an eye with a mature cataract.
were done in April 1997 by 1 surgeon (A.R.V.). Exclusion criteria were incomplete anterior capsulorhexis, posterior capsule tear, and previous eye surgery. The patients’ axial length and lens thickness were measured with a Humphrey ultrasonic biometer. Intraoperatively, the capsulorhexis size and centricity, IOL centration, and the surgeon’s subjective impression of the nucleus’ grade of hardness and scleral rigidity were noted. The condition of the posterior capsule (residual lens fibers and residual plaque) was also observed. Approximately 90% of the viscoelastic agent was removed in all eyes. At the end of surgery, absence or presence of striae was recorded. When striae were present, their number, sharpness, and location were also noted. Follow-up was done of patients in whom striae were present at the end of surgery at 1 and 7 days and 1, 3, and 5 months postoperatively. In eyes in which striae persisted beyond 1 month, the Maddox rod phenomenon was evaluated. The operated eye was covered, a Maddox rod was placed in front of the normal eye, and the patient was asked to see a single light source. Then, the patient was asked to cover the normal eye, and the test was repeated on the operated eye. Statistical analysis was done using the chi-square test for independence and the Student t test.
Results Striae were observed in 56 eyes (Group 1) but absent in 44 (Group 2). The mean patient age was 65.96 years ⫾ 9.15 (SD) in Group 1 and 59.20 ⫾ 10.36 years 1528
in Group 2. The difference was significant (P ⫽ .0012). Of male patients, 50.8% developed striae while 65.7% of female patients developed them. This difference was not statistically significant (P ⫽ .15). Average axial length in Group 1 was 23.47 ⫾ 1.63 mm and in Group 2, 24.12 ⫾ 1.49 mm (P ⫽ .0419). Seven of 8 eyes with an axial length of 22.0 mm or less and 4 of 10 eyes with an axial length of 26.5 mm or more developed striae (P ⫽ .04). Mean lens thickness was greater in Group 1 (4.50 ⫾ 0.43 mm) than in Group 2 (4.13 ⫾ 0.41 mm) (P ⫽ .0001). Striae formation was observed in all eyes with a lens thickness of 5.0 mm or more (n ⫽ 12) (P ⫽ .0018). Mean capsulorhexis size was 5.55 mm in Group 1 and 5.60 mm in Group 2 (P ⫽ .07). In Group 1, 89.20% had a central capsulorhexis and in Group 2, 86.36% (P ⫽ .53). The grade of cataract was judged to be hard (grade 5) in 10 eyes (58.82%) in Group 1 and 7 eyes (41.18%) in Group 2 (P ⫽ .79). Rigidity was judged to be low in 12.50% and 18.18% of eyes, respectively (P ⫽ .4). The IOL was geometrically decentered in 2 eyes intraoperatively, 1 in each group. The posterior capsule was clear in 43 eyes (76.78%) in Group 1 and in 25 eyes (56.81%) in Group 2. Residual posterior capsule plaque was noted in 5 and 3 eyes, respectively. In Group 1, residual lens fibers were found in 14 eyes and in Group 2, 16 eyes. In all eyes, intraoperative striae were present in the direction of the apex of the genus of haptics. In 44 eyes (78.57%), striae were judged to be sharp; in 12 eyes (21.43%), they were faint. One stria was found in 9 eyes
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(16.08%), 2 striae in 39 eyes (69.64%), and multiple striae in 8 eyes (14.28%). In 36 eyes (64.30%), striae remained confined behind the IOL optic, while in 20 eyes (35.7%) they extended beyond the optical margin. The striae disappeared in 8 eyes (14.2%) by 1 day, in 22 eyes (39.2%) by 1 week, in 14 eyes (25.0%) by 1 month, and in 7 eyes (12.5%) by 3 months postoperatively. In the remaining eyes, they disappeared by 5 months postoperatively (Figure 3). No patient reported any visual symptom related to these striae. The authors tried to elicit the Maddox rod phenomenon in the patients in whom the striae persisted beyond 1 month. No patient tested positive for phenomenon.
Discussion Posterior capsule striae can arise during surgery or postoperatively. Table 1 describes the salient features of
both types of capsule striae. A small IOL shows unstable fixation because of inadequate arc of contact between the haptics and capsular bag,3 while a large IOL can cause posterior capsule folds.4 These folds or striae are frequently seen during surgery after an IOL is placed in the capsular bag. A good fit reduces the incidence of PCO.5,6 One can recognize a good fit by looking for intraoperative posterior capsule striae. Occurrence of striae denotes distortion of the capsular bag. Striae formation in more than 2 folds, relatively greater sharpness, and an extending outside optic indicate greater disparity in IOL and capsular bag size. It is important to find out whether these striae permanently or temporarily distort the bag. The incidence of intraoperative posterior capsule striae was 56%. This is not surprising with an overall IOL size of 12.5 mm. The possibility of its occurrence increased in older patients; this is probably explained by the loss of
Figure 3. (Vasavada) A: Intraoperative sharp striae extend beyond the optic. Capsulorhexis is marginally outside the optic. B: Same eye 1 week later. No change in striae. C: Same eye 5 months later. The striae have disappeared. Note the fusion of the anterior and posterior capsule behind the optic.
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Table 1. Posterior capsule striae. Characteristic Pathogenesis
Postoperative Type of fibrous PCO
Intraoperative Disparity in size between IOL and capsular bag
Outcome
Permanent
Temporary
Symptoms
Glare; Maddox rod phenomenon
None
Prevention
Good cortical cleanup; several methods to reduce epithelial cell proliferation and fibrosis suggested
Downsizing IOL
Treatment
Neodymium: YAG laser capsulotomy
No treatment required
capsular elasticity with age. Although a relatively larger proportion of women exhibited striae, there was no statistically significant difference from the incidence in men. Eyes with a shorter axial length developed striae more frequently. There was no evidence that eyes with shorter axial lengths have smaller bag sizes. However, it is probable that such eyes have relatively smaller anterior segment and bag sizes. The available range for the AcrySof IOL is from ⫹10 to ⫹30 diopters. Therefore, we could not implant the lens in extremely short or long eyes and could not enroll patients in whom we could have implanted an IOL outside this range. In Group 1, mean lens thickness was significantly greater than in Group 2. The capsular bag probably loses its elasticity with increased lens thickness, a possible explanation for the more frequent striae. The axial length is generally shorter and the lens usually thicker as age increases.7 We have extensive experience with IOL implantation in children and have found the occurence of capsular striae to be extremely low. We believe capsular elasticity is perhaps more important than bag size and axial length in the genesis of posterior capsule striae. We failed to find a correlation between size and centricity of capsulorhexis and intraoperative striae formation. Testing different IOL designs in cadaver eyes, Ta˜na´ and Belmonte,8 found no statistically significant difference between capsulorhexis diameter and capsular bag distension. We expected harder cataracts with greater lens thickness to produce more striae. However, 1530
we found no significant association. Eyes with low scleral rigidity have more collapsible globes; hence, one would expect a higher incidence of striae formation. We again found no significant association. The relationship between myopia and low scleral rigidity is well known, but we have been unable to include very high myopic patients because of nonavailability of an appropriate IOL power. It is difficult to conclude whether IOL decentration would contribute to striae formation, as we had only 2 cases in our series. Intraoperative PCO is frequently noted in our part of the world. Our findings in this study were consistent with those previously reported.9,10 It is logical to speculate that over time, haptic configuration will remodel to a given bag size, making the posterior capsule striae disappear. Capsular elasticity will also be an important contributing factor. In this study, no patient showed striae at 5 months postoperatively. However, we have seen a patient outside the study population in whom striae persisted for much longer (Figure 4). No patient had symptoms attributed to capsule striae. No patient tested positive for the Maddox rod phenomenon. Fine wrinkles in the posterior capsule may not cause this effect.11 We used Humphrey’s ultrasonic biometer with velocities of 1640 m/sec to measure lens thickness. This measure may not be sensitive enough and could limit lens thickness measurement. Capsular bag size varies in different races.12–14 Therefore, IOL manufacturers may consider tests for
Figure 4. (Vasavada) A rare phenonenon: an eye (not in the study) showing persistence of striae 1 year postoperatively. Note the clear posterior capsule behind optic. Elschnig pearls are present outside the optic margin.
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appropriate IOL size in cadaver and patient eyes at various centers worldwide. It would be interesting to study the incidence of striae with different IOL sizes and configurations and the influence of intraoperative striae formation on ultimate PCO formation.
Conclusion In this study, intraoperative posterior capsule striae in many patients were observed. These striae were seen more frequently in older patients and in eyes with a shorter axial length and increased lens thickness. However, the striae were transient and did not bother the patients. Downsizing the AcrySof IOL may reduce the occurrence of intraoperative posterior capsule striae.
References 1. Richter CU, Steinert RF. Neodymium:yttrium-aluminum-garnet laser posterior capsulotomy. In: Steinert RF, ed, Cataract Surgery: Technique, Complications, & Management. Philadelphia, PA, WB Saunders, 1995; 378 –388 2. Apple DJ, Solomon KD, Tetz MR, et al. Posterior capsule opacification. Surv Ophthalmol 1992; 37:73–116 3. Lim SJ, Kang SJ, Kim HB, Apple DJ. Ideal size of an intraocular lens for capsular bag fixation. J Cataract Refract Surg 1998; 24:397– 402 4. Assia El, Apple DJ. Side-view analysis of the lens. II. Positioning of intraocular lenses. Arch Ophthalmol 1992; 110:94 –97
5. Nakazawa M, Ohtsuki K. Apparent accommodation in pseudophakic eyes after implantation of posterior chamber intraocular lenses. Am J Ophthalmol 1983; 96:435– 438 6. Nishi O. Incidence of posterior capsule opacification in eyes with and without posterior chamber intraocular lenses. J Cataract Refract Surg 1986; 12:519 –522 7. Hoffer KJ. Axial dimension of the human cataractous lens. Arch Ophthalmol 1993; 111:914 –918; erratum p 1626 8. Ta˜na´ P, Belmonte J. Experimental study of different intraocular lens designs implanted in the bag after capsulorhexis. J Cataract Refract Surg 1996; 22:1211–1221 9. Vasavada AR, Chauhan H, Shah G. Incidence of posterior capsular plaque in cataract surgery. J Cataract Refract Surg 1997; 23:798 – 802 10. Peng Q, Hennig H, Vasavada AR, Apple DJ. Posterior capsular plaque; a common feature of cataract surgery in the developing world. Am J Ophthalmol 1988; 125:621– 626 11. Holladay JT, Bishop JE, Lewis JW. Diagnosis and treatment of mysterious light streaks seen by patients following extracapsular cataract extraction. Am Intra-Ocular Implant Soc J 1985; 11:21–23 12. Vasavada A, Singh R. Relationship between lens and capsular bag size. J Cataract Refract Surg 1998; 24:547–551 13. Galand A, Bonhomme L, Collee´ M. Direct measurement of the capsular bag. Am Intra-Ocular Implant Soc J 1984; 10:475– 476 14. Assia El, Apple DJ. Side-view analysis of the lens. I. The crystalline lens and the evacuated bag. Arch Ophthalmol 1992; 110:89 –93
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