- Email: [email protected]
Intraoperative complications of phacoemulsification in eyes with and without pseudoexfoliation
Intraoperative complications of phacoemulsification in eyes with and without pseudoexfoliation Michael Hyams, MD, Nurit Mathalone, MD, Moshe Herskovitz, MD, Yair Hod, MD, David Israeli, MD, Orna Geyer, MD Purpose: To determine the intraoperative complications in a large series of phacoemulsification procedures, including patients with and without pseudoexfoliation, excluding those with marked phacodonesis or lens subluxation. Setting: Department of Ophthalmology, Carmel Medical Centre, Haifa, Israel. Methods: This institutional case-control study included 1501 consecutive phacoemulsification procedures: 137 eyes with pseudoexfoliation and 1364 eyes without this condition. Baseline demographics and clinical factors were collected from the medical files. A comparative analysis of the incidence of intraoperative complications in eyes with or without pseudoexfoliation was calculated. Univariate analysis and multiple logistic regression were used to identify ocular factors that predicted intraoperative complications. Results: There was no significant difference (PO.05) in the rate of intraoperative complications between the pseudoexfoliation (5.8%) and control (4.0%) groups. There were no significant differences in the incidence of capsular breaks, vitreous loss, and zonular ruptures without vitreous loss in the 2 groups. Pseudoexfoliation did not confer a statistically higher risk for intraoperative complications (odds ratio 1.62, 95% confidence interval 0.74-3.55). Conclusion: Phacoemulsification by experienced surgeons is safe in eyes with pseudoexfoliation without marked phacodonesis or lens subluxation. J Cataract Refract Surg 2005; 31:1002–1005 ª 2005 ASCRS and ESCRS
M
any studies have reported an increased incidence of intraoperative complications during manual extracapsular cataract extraction in eyes with pseudoexfoliation (PXF) compared with eyes without this syndrome.1–7 The brittle lens capsule, weak zonules, and reduced mydriasis in eyes with PXF are considered factors leading to the higher rate of complications. Accepted for publication September 3, 2004. From the Department of Ophthalmology, Carmel Medical Centre (Hyams, Mathalone, Hod, Israeli, Geyer) and Rambam Medical Centre (Herskovitz), Haifa, Israel. No author has a financial or proprietary interest in any material or method mentioned. Reprint requests to Michael Hyams, MD, 9 Sport Street, Haifa 34574, Israel. E-mail: [email protected]. 2005 ASCRS and ESCRS Published by Elsevier Inc.
Phacoemulsification has become the norm for routine cataract surgery. In eyes with PXF, the lens tends to be harder and requires increased emulsification time, which can result in more difficult surgery. In addition, with this technique, pressure on the capsular–zonular diaphragm may stretch the capsule and zonules, thereby increasing the risk for zonular/capsular tear and vitreous loss. Reports in the literature concerning the incidence of intraoperative complications during phacoemulsification in eyes with PXF are controversial. Several studies describe an increased rate of intraoperative complications in these eyes.8–10 Two studies of a small number of patients found a similar rate of complications during phacoemulsification in eyes with PXF and in with eyes without PXF.11,12 Larger studies are required to clarify 0886-3350/05/$-see front matter doi:10.1016/j.jcrs.2004.09.051
INTRAOPERATIVE COMPLICATIONS OF PHACO WITH AND WITHOUT PXF
this question. In our study, we investigated the incidence of zonular rupture, capsular break, and vitreous loss during phacoemulsification in a large group of patients with PXF.
Patients and Methods In this case-control study, the records of 1384 consecutive patients (1501 eyes) who had phacoemulsification by 3 experienced surgeons between January 1999 and December 2001 at the Carmel Medical Centre were reviewed. Phacoemulsification was not performed in eyes with severe phacodonesis or subluxated lens during the period of the study. Data of each patient concerning age, sex, intraocular pressure, axial length, pupil diameter following dilation, and the presence of PXF was obtained from the medical files. Diagnosis of PXF was based on the presence of any detectable PXF particles on the anterior lens capsule or at the pupillary margin under slitlamp biomicroscopy with the pupil dilated. The eyes were divided into 2 groups: eyes with PXF (PXF group) and eyes without PXF (control group). The occurrence of posterior capsule tear, zonular dialysis, and vitreous loss during surgery was recorded. Surgery was performed using retrobulbar, peribulbar, or topical anesthesia. Surgical technique consisted of a 3.2 mm clear cornea incision, injection of an ophthalmic viscosurgical device (OVD), and an anterior continuous curvilinear capsulorhexis. Cortical cleavage hydrodissection was followed by in-the-bag phacoemulsification using the divide-and-conquer technique. Cortical removal was performed by automated irrigation/aspiration and vacuum cleaning when necessary. Additional OVD was injected in the capsular bag, and a foldable intraocular lens (IOL) (Corneal ACR6D) was implanted in the capsular bag in most eyes. In all complicated cases, the IOL was implanted in either the sulcus or the anterior chamber. If the pupil diameter was less than 4 mm, iris retraction hooks were used or bimanual pupil stretching was done. Data were analyzed using SPSS 11.0 (SPSS Inc.) software. Then Student t tests were performed to compare means and chi-square tests to compare baseline categorical characteristics and incidence of intraoperative complications between patients with and without PXF. Univariate analysis and multiple logistic regression were used to examine the association between surgical complications and baseline characteristics: odds ratio (OR) and 95% confidence interval (CI) are reported. Statistical significance was defined as P!.05.
Results The study included 137 eyes with PXF (9.1%) and 1364 eyes without PXF (90.9%). Table 1 shows the baseline demographics and clinical details of partic-
Table 1.
Putative baseline demographics and clinical predictors of intraoperative complication. Control Pseudoexfoliation Group (n [ 137) (n [ 1364) P Value Age (years)
77.1 G 7.0
72.6 G 10.5 !.001
Sex (n [%] of males)
53 (38.7%)
605 (44.4%)
NS
Intraocular pressure (mm Hg)
15.5 G 3.7
14.0 G 3.2
!.001
No. of eyes (%)
29 (21.2%)
82 (6%)
!.001
Axial length (mm)
23.7 G 1.8
23.7 G 1.6
NS
Dilated pupil size !5 mm
NS Z not significant (PO.05)
ipants with and without PXF. Patients in the PXF group were significantly older (PXF group 77.0 years G 7.0 (SD) control group 72.6 G 10.5 years; P!.001). Women comprised more than half of each group. The difference in the percentage of women between the 2 groups was not statistically significant. The mean preoperative intraocular pressure was significantly higher in the PXF group (15.5 G 3.6 mm Hg) than in the control group (14.0 G 3.2 mm Hg) (P!.001). The percentage of eyes with pupil diameter less than 5 mm following dilation was significantly higher in the PXF group (21.2% PXF group, 6% control group; P!.01). There was no between-group difference in the preoperative axial length. There was no significant difference (PO.05) in the rate of any intraoperative complication between the PXF group (5.8%) and the control group (4.0%). The incidence of capsular break was 2.9% in both groups. There was no significant difference between the incidence of zonular rupture without vitreous loss in the PXF group (2.9%) and the control group (1.1%). No statistically significant between-group differences were found in the incidence of vitreous loss (PXF group 1.5%, control group 2%) (Table 2). An IOL was implanted in all cases. When a small capsular tear or zonular break occurred without vitreous loss (1.5% of eyes in the PXF group and 3.2% of eyes in the control group), the corneal incision was enlarged to 7 mm and a large-optic, single-piece poly(methyl methacrylate) IOL (Hanita BAL 65) was implanted in the sulcus. Four 10-0 nylon sutures were used to close the corneal incision. A foldable IOL with a large optical
J CATARACT REFRACT SURG—VOL 31, MAY 2005
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INTRAOPERATIVE COMPLICATIONS OF PHACO WITH AND WITHOUT PXF
Table 2.
Surgical data and complications.
Complication/ IOL
Pseudoexfoliation Control (n [ 137) (n [ 1364) P No. of Eyes (%) No. of Eyes (%) Value
Capsular break
4 (2.9)
40 (2.9)
NS
Zonular tear
4 (2.9)
15 (1.1)
NS
Vitreous loss
2 (1.5)
27 (2)
NS
Any complication*
8 (5.8)
55 (4.0)
NS
Sulcus IOL
2 (1.5)
43 (3.2)
NS
Anterior chamber IOL
5 (3.6)
17 (1.2)
!.045
NS Z not significant (PO.05) *At least one complication: zonular tear, vitreous loss, zonular tear with vitreous loss
zone and large haptics was not implanted because it was not available in our institution at the time the study was performed. In patients with a large capsular break with vitreous loss (3.6% of the eyes with PXF and 1.2% of the eyes in the control group; P!.04), anterior vitrectomy was performed followed by injection of acetylcholine chloride (Miochol) to constrict the pupil and an OVD. The corneal incision was then enlarged to 6 mm, and an anterior chamber IOL (Hanita OPAB130) was implanted. Two 10-0 nylon sutures were used to close the corneal incision. Univariate and multivariate ORs with 95% CIs were calculated for each putative predictive factor for the development of intraoperative complications in phacoemulsification: small pupil (less than 5 mm following dilating agents), axial length, and the presence of PXF. Univariate and multivariate analyses gave similar results on multivariate analysis. Pseudo-exfoliation did not confer a statistically higher risk for intraoperative complications (OR 1.62, 95% CI 0.74-3.55). Small pupil was not statistically significant (OR 0.77, 95% CI 0.272.20). A longer axial length appeared to be significantly protective against the occurrence of a zonular tear during surgery (OR 0.63, 95% CI 0.41-0.96).
Discussion We found phacoemulsification to be safe in eyes with PXF. There was no significant difference (PO.05) in the rate of any intraoperative complications between the PXF group (5.8%) and the control group (4.0%). The incidence of capsular break, zonular rupture, and 1004
vitreous loss was similar in eyes with and without PXF. Moreover, PXF was not associated with a statistically higher risk for intraoperative complications (OR 1.62, 95% CI 0.74-3.55). The sample size of this study had a power of 90% to detect difference of 10% with complications in the PXF group versus 3% in the control group. Our study supports the studies of Dosso and coauthors11 and Shastri and Vasavada,12 which found a similar rate of intraoperative complications in the PXF and control groups (without PXF). The main difference between their study and ours is their low sample size, giving a low statistical power: 20 eyes in the study by Dosso and coauthors and 45 eyes in the report by Shastri and Vasavada versus 137 eyes with PXF in our study. In contrast to our results, Scorolli et al.10 report a significantly higher incidence of intraoperative complications in eyes with PXF than in those without this syndrome. Droslum and coauthors5 found a frequency of 9.6% of capsular tear, zonular tear, or vitreous loss in eyes with PXF, compared with 3.7% in eyes without this syndrome. In the study by Shingleton and coauthors,8 the rate of vitreous loss was 4% in the PXF eyes and 0% in the non-PXF group. With the experience we have gained in phacoemulsification, all maneuvers were performed in the center of the lens; a small pupil does not hinder the performance of the technique, and this may explain the lower incidence of intraoperative complications in our study. This is consistent with our finding that a small pupil was not a risk factor for the occurrence of intraoperative complications. If the pupil was less than 4 mm, we used iris retraction hooks or performed the pupil stretch technique. Capsulorhexis was performed within the limits of the outer ring, thus reducing the risk for capsulorhexis dehiscence. In addition, all maneuvers were within the capsular bag, thus avoiding the risk for excessive stress to the zonules. A capsular ring was not used in any case. Other reports have also found that surgical experience is a crucial factor when operating on eyes with PXF.9 Our results are not always comparable with those in other reports because we did not perform phacoemulsification in eyes with severe phacodonesis and subluxated lenses. Shingleton and coauthors8 found that 60% of patients with zonular weakness confirmed by phacodonesis developed vitreous loss during surgery.
J CATARACT REFRACT SURG—VOL 31, MAY 2005
INTRAOPERATIVE COMPLICATIONS OF PHACO WITH AND WITHOUT PXF
It is clear that PXF alone is not the only risk factor to the surgery. A possible reason for results different from other studies may be that the degree of PXF was not graded except to exclude profound weakness cases from the start. We were very careful during the examination of patients to exclude patients with phacodonesis, a characteristic the average examiner may not routinely note. In our series, an IOL was implanted in all complicated PXF cases in the sulcus (1.5%) or in the anterior chamber (3.6%). In contrast, anterior chamber IOLs were not used in the study by Scorolli et al.10 In this study, the use of anterior chamber IOL in PXF was statistically higher. This may be a surrogate for complications. The implantation of an anterior chamber IOL is related to intraoperative complications. Because the rate of intraoperative complications was evaluated per se and was not different between the groups, the finding of a difference in the percentage of anterior chamber IOLs has no meaning. In our study, univariate and multivariate analyses showed that a longer axial length is a protective factor against the occurrence of zonular tear during phacoemulsification. In contrast, Kuchle and coauthors7 report that axial length was shorter in eyes with PXF and complications than in eyes without complications, but the difference was not significant. Further study is needed to evaluate the association between axial length and intraoperative problems during phacoemulsification. A major disadvantage of our survey is that it was retrospective and subject to the limitations of such studies. In conclusion, phacoemulsification by experienced surgeons is safe in eyes with PXF without marked phacodonesis or lens subluxation.
References 1. Alfaiate M, Leite E, Mira J, Cunha-Vaz JG. Prevalance and surgical complications of pseudoexfoliation syndrome in Portuguese patients with senile cataract. J Cataract Refract Surg 1996; 22:972–976 2. Guzek JP, Holm M, Cotter JB, et al. Risk factors for intraoperative complications in 1000 extracapsular cataract cases. Ophthalmology 1987; 94:461–466 ¨ E, Hosxal B, Tekeli O, Gu¨rsel E. Risk factors 3. Abbasog˘lu O for vitreous loss in cataract surgery. Eur J Ophthalmol 2000; 10:227–232 4. Chitkara DK, Smerdon DL. Risk factors, complications, and results in extracapsular cataract extraction. J Cataract Refract Surg 1997; 23:570–574 5. Drolsum L, Haaskjold E, Davanger M. Pseudoexfoliation syndrome and extracapsular cataract extraction. Acta Ophthalmol 1993; 71:765–770 6. Lumme P, Laatikainen L. Exfoliation syndrome and cataract extraction. Am J Ophthalmol 1993; 116:51– 55 7. Ku¨chle M, Scho¨nherr U, Dieckmann U. Risikofaktoren fu¨r kapselruptur und glasko¨rperverlust bei extrakapsula¨rer katarakt extraction; die Erlangen Augenbla¨tterGruppe. Fortschr Ophthalmol 1989; 86:417–421 8. Shingleton BJ, Heltzer J, O’Donoghue MW. Outcome of phacoemulsification in patients with and without pseudoexfoliation syndrome. J Cataract Refract Surg 2003; 29:1080–1086 9. Drolsum L, Haaskjold E, Sandvig K. Phacoemulsification in eyes with pseudoexfoliation. J Cataract Refract Surg 1998; 24:787–792 10. Scorolli L, Scorolli L, Campos EC, et al. Pseudoexfoliation syndrome: a cohort study on intraoperative complications in cataract surgery. Ophthalmologica 1998; 212: 278–280 11. Dosso AA, Bonvin ER, Leuenberger PM. Exfoliation syndrome and phacoemulsification. J Cataract Refract Surg 1997; 23:122–125 12. Shastri L, Vasavada A. Phacoemulsification in Indian eyes with pseudoexfoliation syndrome. J Cataract Refract Surg 2001; 27:1629–1637
J CATARACT REFRACT SURG—VOL 31, MAY 2005
1005
M
any studies have reported an increased incidence of intraoperative complications during manual extracapsular cataract extraction in eyes with pseudoexfoliation (PXF) compared with eyes without this syndrome.1–7 The brittle lens capsule, weak zonules, and reduced mydriasis in eyes with PXF are considered factors leading to the higher rate of complications. Accepted for publication September 3, 2004. From the Department of Ophthalmology, Carmel Medical Centre (Hyams, Mathalone, Hod, Israeli, Geyer) and Rambam Medical Centre (Herskovitz), Haifa, Israel. No author has a financial or proprietary interest in any material or method mentioned. Reprint requests to Michael Hyams, MD, 9 Sport Street, Haifa 34574, Israel. E-mail: [email protected]. 2005 ASCRS and ESCRS Published by Elsevier Inc.
Phacoemulsification has become the norm for routine cataract surgery. In eyes with PXF, the lens tends to be harder and requires increased emulsification time, which can result in more difficult surgery. In addition, with this technique, pressure on the capsular–zonular diaphragm may stretch the capsule and zonules, thereby increasing the risk for zonular/capsular tear and vitreous loss. Reports in the literature concerning the incidence of intraoperative complications during phacoemulsification in eyes with PXF are controversial. Several studies describe an increased rate of intraoperative complications in these eyes.8–10 Two studies of a small number of patients found a similar rate of complications during phacoemulsification in eyes with PXF and in with eyes without PXF.11,12 Larger studies are required to clarify 0886-3350/05/$-see front matter doi:10.1016/j.jcrs.2004.09.051
INTRAOPERATIVE COMPLICATIONS OF PHACO WITH AND WITHOUT PXF
this question. In our study, we investigated the incidence of zonular rupture, capsular break, and vitreous loss during phacoemulsification in a large group of patients with PXF.
Patients and Methods In this case-control study, the records of 1384 consecutive patients (1501 eyes) who had phacoemulsification by 3 experienced surgeons between January 1999 and December 2001 at the Carmel Medical Centre were reviewed. Phacoemulsification was not performed in eyes with severe phacodonesis or subluxated lens during the period of the study. Data of each patient concerning age, sex, intraocular pressure, axial length, pupil diameter following dilation, and the presence of PXF was obtained from the medical files. Diagnosis of PXF was based on the presence of any detectable PXF particles on the anterior lens capsule or at the pupillary margin under slitlamp biomicroscopy with the pupil dilated. The eyes were divided into 2 groups: eyes with PXF (PXF group) and eyes without PXF (control group). The occurrence of posterior capsule tear, zonular dialysis, and vitreous loss during surgery was recorded. Surgery was performed using retrobulbar, peribulbar, or topical anesthesia. Surgical technique consisted of a 3.2 mm clear cornea incision, injection of an ophthalmic viscosurgical device (OVD), and an anterior continuous curvilinear capsulorhexis. Cortical cleavage hydrodissection was followed by in-the-bag phacoemulsification using the divide-and-conquer technique. Cortical removal was performed by automated irrigation/aspiration and vacuum cleaning when necessary. Additional OVD was injected in the capsular bag, and a foldable intraocular lens (IOL) (Corneal ACR6D) was implanted in the capsular bag in most eyes. In all complicated cases, the IOL was implanted in either the sulcus or the anterior chamber. If the pupil diameter was less than 4 mm, iris retraction hooks were used or bimanual pupil stretching was done. Data were analyzed using SPSS 11.0 (SPSS Inc.) software. Then Student t tests were performed to compare means and chi-square tests to compare baseline categorical characteristics and incidence of intraoperative complications between patients with and without PXF. Univariate analysis and multiple logistic regression were used to examine the association between surgical complications and baseline characteristics: odds ratio (OR) and 95% confidence interval (CI) are reported. Statistical significance was defined as P!.05.
Results The study included 137 eyes with PXF (9.1%) and 1364 eyes without PXF (90.9%). Table 1 shows the baseline demographics and clinical details of partic-
Table 1.
Putative baseline demographics and clinical predictors of intraoperative complication. Control Pseudoexfoliation Group (n [ 137) (n [ 1364) P Value Age (years)
77.1 G 7.0
72.6 G 10.5 !.001
Sex (n [%] of males)
53 (38.7%)
605 (44.4%)
NS
Intraocular pressure (mm Hg)
15.5 G 3.7
14.0 G 3.2
!.001
No. of eyes (%)
29 (21.2%)
82 (6%)
!.001
Axial length (mm)
23.7 G 1.8
23.7 G 1.6
NS
Dilated pupil size !5 mm
NS Z not significant (PO.05)
ipants with and without PXF. Patients in the PXF group were significantly older (PXF group 77.0 years G 7.0 (SD) control group 72.6 G 10.5 years; P!.001). Women comprised more than half of each group. The difference in the percentage of women between the 2 groups was not statistically significant. The mean preoperative intraocular pressure was significantly higher in the PXF group (15.5 G 3.6 mm Hg) than in the control group (14.0 G 3.2 mm Hg) (P!.001). The percentage of eyes with pupil diameter less than 5 mm following dilation was significantly higher in the PXF group (21.2% PXF group, 6% control group; P!.01). There was no between-group difference in the preoperative axial length. There was no significant difference (PO.05) in the rate of any intraoperative complication between the PXF group (5.8%) and the control group (4.0%). The incidence of capsular break was 2.9% in both groups. There was no significant difference between the incidence of zonular rupture without vitreous loss in the PXF group (2.9%) and the control group (1.1%). No statistically significant between-group differences were found in the incidence of vitreous loss (PXF group 1.5%, control group 2%) (Table 2). An IOL was implanted in all cases. When a small capsular tear or zonular break occurred without vitreous loss (1.5% of eyes in the PXF group and 3.2% of eyes in the control group), the corneal incision was enlarged to 7 mm and a large-optic, single-piece poly(methyl methacrylate) IOL (Hanita BAL 65) was implanted in the sulcus. Four 10-0 nylon sutures were used to close the corneal incision. A foldable IOL with a large optical
J CATARACT REFRACT SURG—VOL 31, MAY 2005
1003
INTRAOPERATIVE COMPLICATIONS OF PHACO WITH AND WITHOUT PXF
Table 2.
Surgical data and complications.
Complication/ IOL
Pseudoexfoliation Control (n [ 137) (n [ 1364) P No. of Eyes (%) No. of Eyes (%) Value
Capsular break
4 (2.9)
40 (2.9)
NS
Zonular tear
4 (2.9)
15 (1.1)
NS
Vitreous loss
2 (1.5)
27 (2)
NS
Any complication*
8 (5.8)
55 (4.0)
NS
Sulcus IOL
2 (1.5)
43 (3.2)
NS
Anterior chamber IOL
5 (3.6)
17 (1.2)
!.045
NS Z not significant (PO.05) *At least one complication: zonular tear, vitreous loss, zonular tear with vitreous loss
zone and large haptics was not implanted because it was not available in our institution at the time the study was performed. In patients with a large capsular break with vitreous loss (3.6% of the eyes with PXF and 1.2% of the eyes in the control group; P!.04), anterior vitrectomy was performed followed by injection of acetylcholine chloride (Miochol) to constrict the pupil and an OVD. The corneal incision was then enlarged to 6 mm, and an anterior chamber IOL (Hanita OPAB130) was implanted. Two 10-0 nylon sutures were used to close the corneal incision. Univariate and multivariate ORs with 95% CIs were calculated for each putative predictive factor for the development of intraoperative complications in phacoemulsification: small pupil (less than 5 mm following dilating agents), axial length, and the presence of PXF. Univariate and multivariate analyses gave similar results on multivariate analysis. Pseudo-exfoliation did not confer a statistically higher risk for intraoperative complications (OR 1.62, 95% CI 0.74-3.55). Small pupil was not statistically significant (OR 0.77, 95% CI 0.272.20). A longer axial length appeared to be significantly protective against the occurrence of a zonular tear during surgery (OR 0.63, 95% CI 0.41-0.96).
Discussion We found phacoemulsification to be safe in eyes with PXF. There was no significant difference (PO.05) in the rate of any intraoperative complications between the PXF group (5.8%) and the control group (4.0%). The incidence of capsular break, zonular rupture, and 1004
vitreous loss was similar in eyes with and without PXF. Moreover, PXF was not associated with a statistically higher risk for intraoperative complications (OR 1.62, 95% CI 0.74-3.55). The sample size of this study had a power of 90% to detect difference of 10% with complications in the PXF group versus 3% in the control group. Our study supports the studies of Dosso and coauthors11 and Shastri and Vasavada,12 which found a similar rate of intraoperative complications in the PXF and control groups (without PXF). The main difference between their study and ours is their low sample size, giving a low statistical power: 20 eyes in the study by Dosso and coauthors and 45 eyes in the report by Shastri and Vasavada versus 137 eyes with PXF in our study. In contrast to our results, Scorolli et al.10 report a significantly higher incidence of intraoperative complications in eyes with PXF than in those without this syndrome. Droslum and coauthors5 found a frequency of 9.6% of capsular tear, zonular tear, or vitreous loss in eyes with PXF, compared with 3.7% in eyes without this syndrome. In the study by Shingleton and coauthors,8 the rate of vitreous loss was 4% in the PXF eyes and 0% in the non-PXF group. With the experience we have gained in phacoemulsification, all maneuvers were performed in the center of the lens; a small pupil does not hinder the performance of the technique, and this may explain the lower incidence of intraoperative complications in our study. This is consistent with our finding that a small pupil was not a risk factor for the occurrence of intraoperative complications. If the pupil was less than 4 mm, we used iris retraction hooks or performed the pupil stretch technique. Capsulorhexis was performed within the limits of the outer ring, thus reducing the risk for capsulorhexis dehiscence. In addition, all maneuvers were within the capsular bag, thus avoiding the risk for excessive stress to the zonules. A capsular ring was not used in any case. Other reports have also found that surgical experience is a crucial factor when operating on eyes with PXF.9 Our results are not always comparable with those in other reports because we did not perform phacoemulsification in eyes with severe phacodonesis and subluxated lenses. Shingleton and coauthors8 found that 60% of patients with zonular weakness confirmed by phacodonesis developed vitreous loss during surgery.
J CATARACT REFRACT SURG—VOL 31, MAY 2005
INTRAOPERATIVE COMPLICATIONS OF PHACO WITH AND WITHOUT PXF
It is clear that PXF alone is not the only risk factor to the surgery. A possible reason for results different from other studies may be that the degree of PXF was not graded except to exclude profound weakness cases from the start. We were very careful during the examination of patients to exclude patients with phacodonesis, a characteristic the average examiner may not routinely note. In our series, an IOL was implanted in all complicated PXF cases in the sulcus (1.5%) or in the anterior chamber (3.6%). In contrast, anterior chamber IOLs were not used in the study by Scorolli et al.10 In this study, the use of anterior chamber IOL in PXF was statistically higher. This may be a surrogate for complications. The implantation of an anterior chamber IOL is related to intraoperative complications. Because the rate of intraoperative complications was evaluated per se and was not different between the groups, the finding of a difference in the percentage of anterior chamber IOLs has no meaning. In our study, univariate and multivariate analyses showed that a longer axial length is a protective factor against the occurrence of zonular tear during phacoemulsification. In contrast, Kuchle and coauthors7 report that axial length was shorter in eyes with PXF and complications than in eyes without complications, but the difference was not significant. Further study is needed to evaluate the association between axial length and intraoperative problems during phacoemulsification. A major disadvantage of our survey is that it was retrospective and subject to the limitations of such studies. In conclusion, phacoemulsification by experienced surgeons is safe in eyes with PXF without marked phacodonesis or lens subluxation.
References 1. Alfaiate M, Leite E, Mira J, Cunha-Vaz JG. Prevalance and surgical complications of pseudoexfoliation syndrome in Portuguese patients with senile cataract. J Cataract Refract Surg 1996; 22:972–976 2. Guzek JP, Holm M, Cotter JB, et al. Risk factors for intraoperative complications in 1000 extracapsular cataract cases. Ophthalmology 1987; 94:461–466 ¨ E, Hosxal B, Tekeli O, Gu¨rsel E. Risk factors 3. Abbasog˘lu O for vitreous loss in cataract surgery. Eur J Ophthalmol 2000; 10:227–232 4. Chitkara DK, Smerdon DL. Risk factors, complications, and results in extracapsular cataract extraction. J Cataract Refract Surg 1997; 23:570–574 5. Drolsum L, Haaskjold E, Davanger M. Pseudoexfoliation syndrome and extracapsular cataract extraction. Acta Ophthalmol 1993; 71:765–770 6. Lumme P, Laatikainen L. Exfoliation syndrome and cataract extraction. Am J Ophthalmol 1993; 116:51– 55 7. Ku¨chle M, Scho¨nherr U, Dieckmann U. Risikofaktoren fu¨r kapselruptur und glasko¨rperverlust bei extrakapsula¨rer katarakt extraction; die Erlangen Augenbla¨tterGruppe. Fortschr Ophthalmol 1989; 86:417–421 8. Shingleton BJ, Heltzer J, O’Donoghue MW. Outcome of phacoemulsification in patients with and without pseudoexfoliation syndrome. J Cataract Refract Surg 2003; 29:1080–1086 9. Drolsum L, Haaskjold E, Sandvig K. Phacoemulsification in eyes with pseudoexfoliation. J Cataract Refract Surg 1998; 24:787–792 10. Scorolli L, Scorolli L, Campos EC, et al. Pseudoexfoliation syndrome: a cohort study on intraoperative complications in cataract surgery. Ophthalmologica 1998; 212: 278–280 11. Dosso AA, Bonvin ER, Leuenberger PM. Exfoliation syndrome and phacoemulsification. J Cataract Refract Surg 1997; 23:122–125 12. Shastri L, Vasavada A. Phacoemulsification in Indian eyes with pseudoexfoliation syndrome. J Cataract Refract Surg 2001; 27:1629–1637
J CATARACT REFRACT SURG—VOL 31, MAY 2005
1005