- Email: [email protected]
Cataract surgery management in patients taking tamsulosin
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006
ARTICLES
Cataract surgery management in patients taking tamsulosin Staged approach Sridhar Manvikar, FRCOphth, David Allen, FRCS, FRCOphth
PURPOSE: To demonstrate a progressive approach to the problems of intraoperative floppy-iris syndrome (IFIS) in cataract surgery caused by tamsulosin. SETTING: Cataract Treatment Center, Sunderland Eye Infirmary, Sunderland, United Kingdom. METHODS: Thirty-two eyes of 20 patients who were using tamsulosin had cataract surgery by the same surgeon using the same technique. Patients received standard preoperative eyedrops consisting of topical cyclopentolate, phenylephrine, and diclofenac. When necessary, intracameral phenylephrine, iris hooks, or both were used. All cases were videotaped and analyzed for surgical complications. RESULTS: The degree of IFIS manifested varied widely in the patients: Seventeen of 32 eyes (53%) had good mydriasis preoperatively (type 1 and type 2 pupils); however, in 7 of the 17 eyes (43%), the pupils constricted later during surgery (type 2 pupils). Twelve eyes (38%) had a mid-dilated pupil that sometimes constricted later (type 3 pupils), and 3 eyes (9%) had poor dilation at the beginning of surgery (type 4 pupils). There were no surgical complications attributed to IFIS. Full IFIS manifestation varied between eyes of the same patient. Some eyes required no intervention. Intraoperative pupil constriction was reversed with intracameral phenylephrine, which also prevented iris prolapse and billowing and further pupil constriction in patients who had medium to small pupils preoperatively. CONCLUSION: A staged approach in managing pupils in IFIS and using phenylephrine intracamerally when necessary effectively prevented serious intraoperative complications. J Cataract Refract Surg 2006; 32:1611–1614 Q 2006 ASCRS and ESCRS
Intraoperative floppy-iris syndrome (IFIS) as described by Chang and Campbell1 is a condition characterized by three signs that occur during cataract extraction. The signs include a floppy iris that billows in the normal irrigation currents of the anterior chamber, a propensity for the iris to prolapse through the phacoemulsification and side-port
Accepted for publication April 30, 2006. From the Sunderland Eye Infirmary, Sunderland, United Kingdom. Presented in part at the ASCRS Symposium on Cataract, IOL and Refractive Surgery, San Francisco, California, USA, March 2006. Neither author has a proprietary or financial interest in the material or method mentioned. Corresponding author: David Allen, FRCOphth, Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland, SR2 9HP, United Kingdom. E-mail: [email protected]. Q 2006 ASCRS and ESCRS Published by Elsevier Inc.
incisions, and progressive pupil constriction during surgery. These features, which are thought to be caused by a lack of tone of the dilator smooth muscle of the iris, are seen in a high proportion of patients who are using tamsulosin (Flomax). The syndrome is also seen in a small number of patients who are not taking tamsulosin or similar medications. Intraoperative floppy-iris syndrome occurs in approximately 2% of all cataract surgery patients.1 Tamsulosin is an a1 adrenergic receptor antagonist. It is a systemic sympatheticolytic that blocks a1-adrenergic receptors. Currently, there are 3 known a1-adrenergic receptor subtypes (a1A, a1B, and a1D).2 In treating lower urinary tract symptoms, a1A and a1D receptors are targeted because these receptors are prevalent in bladder neck smooth muscle.3 Other available a1-adrenergic receptor antagonists include alfuzosin, doxazosin, and terazosin. Intraoperative floppy-iris syndrome is associated with all 0886-3350/06/$-see front matter doi:10.1016/j.jcrs.2006.04.037
1611
CATARACT SURGERY IN PATIENTS TAKING TAMSULOSIN
these a1-adrenergic receptor antagonists, although it is much more common with tamsulosin, which is highly selective for the a1A receptor (J. Helzner, ‘‘Managing floppy Iris Syndrome. Use of Flomax Has Been Tied to This Complication,’’ in Ophthalmology Management 2005; April, pages 22, 74. Available at http://www.ophmanagement. com/article.aspx?articleZ86311 [online]. Accessed February 20, 2006). Contraction of the iris dilator muscle in rabbits, ratsdand probably humansdis mediated via a1A-receptors,4 and this may explain why tamsulosin in particular is associated with IFIS. The conventional methods of pupil stretching and partial-thickness sphincterotomies are little help in achieving mydriasis1 in IFIS, and the IFIS effects can be seen several months after tamsulosin is stopped. In normal clinical practice, a1A-adrenergic receptor agonists such as phenylephrine are used to induce mydriasis. Recent studies show that intracameral mydriatics, including phenylephrine, effectively dilate pupils.5 We also noticed anecdotally that phenylephrine injected intracamerally causes additional dilation in small to mid-dilated pupils, even though the drug had been used topically before surgery. In August 2005, it was decided that all patients on tamsulosin having cataract surgery at Sunderland Eye Infirmary should be operated on by the same surgeon to ascertain the best management approach. We attempted to determine whether phenylephrine injected directly into the anterior chamber would be beneficial in these cases when IFIS occurred.
PATIENTS AND METHODS Thirty-two eyes of 20 patients who were on tamsulosin for at least 6 months before cataract surgery were operated on by the same surgeon (D.A.) using topical anesthesia and the phacochop technique. Twelve patients had second-eye surgery within 8 weeks of the first (24 eyes). All patients continued using tamsulosin. Apart from the first patient in this series, who had atropine drops at 30 minutes and 15 minutes before surgery, patients had the standard preoperative preparation used in the unit (topical cyclopentolate, phenylephrine, and diclofenac). All patients had epinephrine added to the balanced salt solution (BSS) infusion bottle during surgery. When the pupil was normally dilated, surgery commenced as usual. When the pupil was small or middilated (!4.5 mm) at the outset, phenylephrine was injected into the anterior chamber. When there was significant pupil constriction or other IFIS effects during surgery, intracameral phenylephrine, iris hooks, or both were used. All cases were videotaped and the tapes subsequently analyzed for IFIS surgical complications and the effect of intracameral phenylephrine on pupil dilation and iris prolapse. Intracameral phenylephrine was prepared using 0.25 mL of unpreserved phenylephrine 2.5% (Minims) diluted with 2 mL of BSS in a 2 mL syringe. The pH of the intracameral phenylephrine was 6.4. When used during surgery, at least 30 seconds were allowed to ensure maximum effect before the agent was washed out.
1612
RESULTS
During the study, 2678 eyes had cataract surgery, 1042 in men. The 32 eyes in this series therefore represented 1.2% of total cataract surgeries and 3.1% of total surgeries in men. The pupil dilations at the outset and the behavior during surgery were used to classify the pupils into 4 types (Table 1). Type 1 pupils were well dilated at the start of the operation and remained so throughout the procedure. Type 2 pupils were well dilated at the start but constricted as the operation progressed. Type 3 pupils were mid-dilated preoperatively and remained the same or constricted further as the operation progressed. Type 4 pupils were poorly dilated from the outset. Table 1 shows the number and percentage of eyes in each category. There were significant differences in how the pupils behaved in fellow eyes of several patients. These differences included whether intracameral phenylephrine was needed in both eyes of the same patient. The 1 patient who had atropine preoperatively in the first eye had no IFIS problems. However, there were also no problems in the second eye, which did not received atropine. Table 2 shows the differences in patients who had bilateral cataract surgery within 8 weeks. The effect of intracameral phenylephrine on pupil dilation used at the beginning of or during surgery (n Z 22 eyes) varied. Some pupils dilated further with the use of intracameral phenylephrine, while others did not appear to change significantly. However, in all the cases that had intracameral phenylephrine because of pupil constriction or significant iris prolapse in the incisions, the use of intracameral phenylephrine stopped the tendency of the iris to prolapse and caused the pupil to dilate back to its preoperative size (Table 3). Unlike the response to intracameral lidocaine in previously undilated patients (almost instantaneous dilation), the response to intracameral phenylephrine was slower, taking up to 30 to 35 seconds for maximum effect. In 1 patient, the iris was aspirated into the phaco port during nucleus removal but the iris was not damaged. In another patient, the capsulorhexis tore more peripherally Table 1. Types of pupil dilation in IFIS (N Z 32).
Pupil Grade Type 1 (well dilated, no problems) Type 2 (well dilated at first: constricted later) Type 3 (mid-dilated at first C/ constriction later) Type 4 (poor dilation at outset)
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006
Number of Eyes (%) 10
(31)
7
(22)
12
(38)
3
(9)
CATARACT SURGERY IN PATIENTS TAKING TAMSULOSIN
Table 2. Pupils in fellow eyes in the 24 bilateral cases (12 patients).
Finding No need for IPE, either eye IPE needed, both eyes 1st eye, no problems 2nd eye, IPE 1st eye, IPE 2nd eye, no problems 1st eye, preop atropine, no problems 2nd eye, no preop atropine, no problems 1st eye, IPE C iris hooks 2nd eye, IPE C no iris hooks IPE Z intracameral phenylepherine
Pupil Grade
Patients
1 2 3 2 1 2 2 2 1
2 4 3
1 1
1 4 4
1
than intended, but this was not considered to be related to tamsulosin IFIS. No other surgical complications were noted. DISCUSSION
Alpha 1 adrenergic receptor antagonists are used extensively to manage symptoms of benign prostatic hyperplasia and other lower urinary tract symptoms in the elderly population. Although the prevalence of IFIS is reported to be approximately 2% in an elderly population,1 the actual number of patients using these medications may be greater and prevalence of IFIS much higher.6 Although it cannot be proved that there was 100% case ascertainment in our series, it would appear that tamsulosin use was less frequent in England in 2005 than that originally reported in California.1 Different ways to manage small pupils and floppy irises have been suggested and include the use of iris retractors, pupil expansion rings or ophthalmic viscosurgical devices (OVDs) such as Healon5 (sodium hyaluronate 2.3%).1 We did not find the use of dispersive OVDs helpful in Table 3. Intracameral phenylephrine and intraoperative pupil dilation (n Z 22 eyes).
IPE At commencement of surgery During surgery
No Additional Pupil Additional Pupil Dilation; No Further Iris Prolapse or Constriction Dilation 3
3
13
3
IPE Z intracameral phenylepherine
compartmentalizing the floppy iris. During the period in which we were conducting this study, Gurbaxani and Packard7 reported using intracameral phenylephrine in 7 eyes of patients taking tamsulosin. They used intracameral phenylephrine in all patients and reported no significant surgical problems caused by IFIS. Phenylephrine hydrochloride acts predominantly on the a1 receptors of the iris.8 We suggest the intracameral injection of phenylephrine acts directly on the a1 receptors and provides maximum stimulation that causes the pupil to dilate or at least increases the tone of the dilator muscle and prevents iris billowing. The potential toxicity of intracameral phenylephrine as used in our study has not been established. However, phenylephrine 1.5% was a constituent in a multidrug solution used by Lundberg and Behndig,5 who found no statistically significantly different rate of endothelial cell loss between patients who had received the intracameral mydriatic solution and patients who had topical mydriatics. None of our cases had clinical evidence of corneal decompensation postoperatively. The manifestations of IFIS are variable, even in fellow eyes of the same patient. Therefore, we recommend that until studies confirm the long-term safety of intracameral phenylephrine, its use be limited to patients with a tendency toward pupil constriction, potentially leading to sight-threatening complications. During this study, we used our standard phacoemulsification fluidics parameters to be sure the effects we observed were due to intracameral phenylephrine. The use of OVDs such as Healon5 coupled with slow-motion fluidics has been advocated by some.1,9 We intend to study the use of such less aggressive fluidics to determine whether alteration of phaco parameters will make the procedure safer. The recently introduced torsional phaco modality on the Infiniti Lens System (Alcon Laboratories) provides low repulsion, high-efficiency characteristics that could be beneficial in IFIS. As a result of our experience with this large series, we propose the following interim algorithm to manage IFIS patients. More than half (53%) will have a large pupil at the outset. About half these pupils will constrict during surgery; intracameral phenylephrine will redilate the pupil to its original size and reduce or prevent prolapse. Thirty-eight percent will have a mid-dilated pupil. Although intracameral phenylephrine at the outset will not necessarily enlarge most, it will prevent further constriction or will redilate the pupil moderately. Approximately 9% will have a small pupil, and if the surgeon is experienced with small pupils,
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006
1613
CATARACT SURGERY IN PATIENTS TAKING TAMSULOSIN
intracameral phenylephrine may allow safe surgery without the use of hooks or pupil expanders. Although we have no direct proof that the use of intracameral phenylephrine led to an absence of IFIS-related complications in this large series, we believe that the evidence of redilation of the pupils that constricted during surgery and the cessation of observed iris prolapse after using intracameral phenylephrine are powerful arguments for the effectiveness of this intervention. REFERENCES 1. Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg 2005; 31:664–673 2. Hawrylyshyn KA, Michelotti GA, Coge´ F, et al. Update on human a1adrenoceptor subtype signaling and genomic organization. Trends Pharmacol Sci 2004; 25:449–455
1614
3. Schwinn DA, Price DT, Narayan P. a1-adrenoceptor subtype selectivity and lower urinary tract symptoms. Mayo Clinic Proc 2004; 79:1423– 1434 4. Yu Y, Koss MC. a1A-adrenoceptors mediate sympathetically evoked pupillary dilation in rats. J Pharmacol Exp Ther 2002; 300:521–525 5. Lundberg B, Behndig A. Intracameral mydriatics in phacoemulsification cataract surgery. J Cataract Refract Surg 2003; 29:2366–2371 6. Schwinn DA, Afshari NA. a1-adrenergic antagonists and floppy iris syndrome: tip of the iceberg? [editorial] Ophthalmology 2005; 112:2059– 2060 7. Gurbaxani A, Packard R. Intracameral phenylephrine to prevent floppy iris syndrome during cataract surgery in patients on tamsulosin. Eye advance online publication, November 11, 2005. Available at: http://www.nature.com/eye/journal/vaop/ncurrent/abs/6702172a.html. Accessed April 1, 2006 8. Lowe FC. Role of the newer alpha1-adrenergic-receptor antagonists in the treatment of benign prostatic hyperplasia-related lower urinary tract symptoms. Clin Ther 2004; 26:1701–1713 9. Osher RH. Association between IFIS and Flomax. J Cataract Refract Surg 2006; 32:547
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006
ARTICLES
Cataract surgery management in patients taking tamsulosin Staged approach Sridhar Manvikar, FRCOphth, David Allen, FRCS, FRCOphth
PURPOSE: To demonstrate a progressive approach to the problems of intraoperative floppy-iris syndrome (IFIS) in cataract surgery caused by tamsulosin. SETTING: Cataract Treatment Center, Sunderland Eye Infirmary, Sunderland, United Kingdom. METHODS: Thirty-two eyes of 20 patients who were using tamsulosin had cataract surgery by the same surgeon using the same technique. Patients received standard preoperative eyedrops consisting of topical cyclopentolate, phenylephrine, and diclofenac. When necessary, intracameral phenylephrine, iris hooks, or both were used. All cases were videotaped and analyzed for surgical complications. RESULTS: The degree of IFIS manifested varied widely in the patients: Seventeen of 32 eyes (53%) had good mydriasis preoperatively (type 1 and type 2 pupils); however, in 7 of the 17 eyes (43%), the pupils constricted later during surgery (type 2 pupils). Twelve eyes (38%) had a mid-dilated pupil that sometimes constricted later (type 3 pupils), and 3 eyes (9%) had poor dilation at the beginning of surgery (type 4 pupils). There were no surgical complications attributed to IFIS. Full IFIS manifestation varied between eyes of the same patient. Some eyes required no intervention. Intraoperative pupil constriction was reversed with intracameral phenylephrine, which also prevented iris prolapse and billowing and further pupil constriction in patients who had medium to small pupils preoperatively. CONCLUSION: A staged approach in managing pupils in IFIS and using phenylephrine intracamerally when necessary effectively prevented serious intraoperative complications. J Cataract Refract Surg 2006; 32:1611–1614 Q 2006 ASCRS and ESCRS
Intraoperative floppy-iris syndrome (IFIS) as described by Chang and Campbell1 is a condition characterized by three signs that occur during cataract extraction. The signs include a floppy iris that billows in the normal irrigation currents of the anterior chamber, a propensity for the iris to prolapse through the phacoemulsification and side-port
Accepted for publication April 30, 2006. From the Sunderland Eye Infirmary, Sunderland, United Kingdom. Presented in part at the ASCRS Symposium on Cataract, IOL and Refractive Surgery, San Francisco, California, USA, March 2006. Neither author has a proprietary or financial interest in the material or method mentioned. Corresponding author: David Allen, FRCOphth, Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland, SR2 9HP, United Kingdom. E-mail: [email protected]. Q 2006 ASCRS and ESCRS Published by Elsevier Inc.
incisions, and progressive pupil constriction during surgery. These features, which are thought to be caused by a lack of tone of the dilator smooth muscle of the iris, are seen in a high proportion of patients who are using tamsulosin (Flomax). The syndrome is also seen in a small number of patients who are not taking tamsulosin or similar medications. Intraoperative floppy-iris syndrome occurs in approximately 2% of all cataract surgery patients.1 Tamsulosin is an a1 adrenergic receptor antagonist. It is a systemic sympatheticolytic that blocks a1-adrenergic receptors. Currently, there are 3 known a1-adrenergic receptor subtypes (a1A, a1B, and a1D).2 In treating lower urinary tract symptoms, a1A and a1D receptors are targeted because these receptors are prevalent in bladder neck smooth muscle.3 Other available a1-adrenergic receptor antagonists include alfuzosin, doxazosin, and terazosin. Intraoperative floppy-iris syndrome is associated with all 0886-3350/06/$-see front matter doi:10.1016/j.jcrs.2006.04.037
1611
CATARACT SURGERY IN PATIENTS TAKING TAMSULOSIN
these a1-adrenergic receptor antagonists, although it is much more common with tamsulosin, which is highly selective for the a1A receptor (J. Helzner, ‘‘Managing floppy Iris Syndrome. Use of Flomax Has Been Tied to This Complication,’’ in Ophthalmology Management 2005; April, pages 22, 74. Available at http://www.ophmanagement. com/article.aspx?articleZ86311 [online]. Accessed February 20, 2006). Contraction of the iris dilator muscle in rabbits, ratsdand probably humansdis mediated via a1A-receptors,4 and this may explain why tamsulosin in particular is associated with IFIS. The conventional methods of pupil stretching and partial-thickness sphincterotomies are little help in achieving mydriasis1 in IFIS, and the IFIS effects can be seen several months after tamsulosin is stopped. In normal clinical practice, a1A-adrenergic receptor agonists such as phenylephrine are used to induce mydriasis. Recent studies show that intracameral mydriatics, including phenylephrine, effectively dilate pupils.5 We also noticed anecdotally that phenylephrine injected intracamerally causes additional dilation in small to mid-dilated pupils, even though the drug had been used topically before surgery. In August 2005, it was decided that all patients on tamsulosin having cataract surgery at Sunderland Eye Infirmary should be operated on by the same surgeon to ascertain the best management approach. We attempted to determine whether phenylephrine injected directly into the anterior chamber would be beneficial in these cases when IFIS occurred.
PATIENTS AND METHODS Thirty-two eyes of 20 patients who were on tamsulosin for at least 6 months before cataract surgery were operated on by the same surgeon (D.A.) using topical anesthesia and the phacochop technique. Twelve patients had second-eye surgery within 8 weeks of the first (24 eyes). All patients continued using tamsulosin. Apart from the first patient in this series, who had atropine drops at 30 minutes and 15 minutes before surgery, patients had the standard preoperative preparation used in the unit (topical cyclopentolate, phenylephrine, and diclofenac). All patients had epinephrine added to the balanced salt solution (BSS) infusion bottle during surgery. When the pupil was normally dilated, surgery commenced as usual. When the pupil was small or middilated (!4.5 mm) at the outset, phenylephrine was injected into the anterior chamber. When there was significant pupil constriction or other IFIS effects during surgery, intracameral phenylephrine, iris hooks, or both were used. All cases were videotaped and the tapes subsequently analyzed for IFIS surgical complications and the effect of intracameral phenylephrine on pupil dilation and iris prolapse. Intracameral phenylephrine was prepared using 0.25 mL of unpreserved phenylephrine 2.5% (Minims) diluted with 2 mL of BSS in a 2 mL syringe. The pH of the intracameral phenylephrine was 6.4. When used during surgery, at least 30 seconds were allowed to ensure maximum effect before the agent was washed out.
1612
RESULTS
During the study, 2678 eyes had cataract surgery, 1042 in men. The 32 eyes in this series therefore represented 1.2% of total cataract surgeries and 3.1% of total surgeries in men. The pupil dilations at the outset and the behavior during surgery were used to classify the pupils into 4 types (Table 1). Type 1 pupils were well dilated at the start of the operation and remained so throughout the procedure. Type 2 pupils were well dilated at the start but constricted as the operation progressed. Type 3 pupils were mid-dilated preoperatively and remained the same or constricted further as the operation progressed. Type 4 pupils were poorly dilated from the outset. Table 1 shows the number and percentage of eyes in each category. There were significant differences in how the pupils behaved in fellow eyes of several patients. These differences included whether intracameral phenylephrine was needed in both eyes of the same patient. The 1 patient who had atropine preoperatively in the first eye had no IFIS problems. However, there were also no problems in the second eye, which did not received atropine. Table 2 shows the differences in patients who had bilateral cataract surgery within 8 weeks. The effect of intracameral phenylephrine on pupil dilation used at the beginning of or during surgery (n Z 22 eyes) varied. Some pupils dilated further with the use of intracameral phenylephrine, while others did not appear to change significantly. However, in all the cases that had intracameral phenylephrine because of pupil constriction or significant iris prolapse in the incisions, the use of intracameral phenylephrine stopped the tendency of the iris to prolapse and caused the pupil to dilate back to its preoperative size (Table 3). Unlike the response to intracameral lidocaine in previously undilated patients (almost instantaneous dilation), the response to intracameral phenylephrine was slower, taking up to 30 to 35 seconds for maximum effect. In 1 patient, the iris was aspirated into the phaco port during nucleus removal but the iris was not damaged. In another patient, the capsulorhexis tore more peripherally Table 1. Types of pupil dilation in IFIS (N Z 32).
Pupil Grade Type 1 (well dilated, no problems) Type 2 (well dilated at first: constricted later) Type 3 (mid-dilated at first C/ constriction later) Type 4 (poor dilation at outset)
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006
Number of Eyes (%) 10
(31)
7
(22)
12
(38)
3
(9)
CATARACT SURGERY IN PATIENTS TAKING TAMSULOSIN
Table 2. Pupils in fellow eyes in the 24 bilateral cases (12 patients).
Finding No need for IPE, either eye IPE needed, both eyes 1st eye, no problems 2nd eye, IPE 1st eye, IPE 2nd eye, no problems 1st eye, preop atropine, no problems 2nd eye, no preop atropine, no problems 1st eye, IPE C iris hooks 2nd eye, IPE C no iris hooks IPE Z intracameral phenylepherine
Pupil Grade
Patients
1 2 3 2 1 2 2 2 1
2 4 3
1 1
1 4 4
1
than intended, but this was not considered to be related to tamsulosin IFIS. No other surgical complications were noted. DISCUSSION
Alpha 1 adrenergic receptor antagonists are used extensively to manage symptoms of benign prostatic hyperplasia and other lower urinary tract symptoms in the elderly population. Although the prevalence of IFIS is reported to be approximately 2% in an elderly population,1 the actual number of patients using these medications may be greater and prevalence of IFIS much higher.6 Although it cannot be proved that there was 100% case ascertainment in our series, it would appear that tamsulosin use was less frequent in England in 2005 than that originally reported in California.1 Different ways to manage small pupils and floppy irises have been suggested and include the use of iris retractors, pupil expansion rings or ophthalmic viscosurgical devices (OVDs) such as Healon5 (sodium hyaluronate 2.3%).1 We did not find the use of dispersive OVDs helpful in Table 3. Intracameral phenylephrine and intraoperative pupil dilation (n Z 22 eyes).
IPE At commencement of surgery During surgery
No Additional Pupil Additional Pupil Dilation; No Further Iris Prolapse or Constriction Dilation 3
3
13
3
IPE Z intracameral phenylepherine
compartmentalizing the floppy iris. During the period in which we were conducting this study, Gurbaxani and Packard7 reported using intracameral phenylephrine in 7 eyes of patients taking tamsulosin. They used intracameral phenylephrine in all patients and reported no significant surgical problems caused by IFIS. Phenylephrine hydrochloride acts predominantly on the a1 receptors of the iris.8 We suggest the intracameral injection of phenylephrine acts directly on the a1 receptors and provides maximum stimulation that causes the pupil to dilate or at least increases the tone of the dilator muscle and prevents iris billowing. The potential toxicity of intracameral phenylephrine as used in our study has not been established. However, phenylephrine 1.5% was a constituent in a multidrug solution used by Lundberg and Behndig,5 who found no statistically significantly different rate of endothelial cell loss between patients who had received the intracameral mydriatic solution and patients who had topical mydriatics. None of our cases had clinical evidence of corneal decompensation postoperatively. The manifestations of IFIS are variable, even in fellow eyes of the same patient. Therefore, we recommend that until studies confirm the long-term safety of intracameral phenylephrine, its use be limited to patients with a tendency toward pupil constriction, potentially leading to sight-threatening complications. During this study, we used our standard phacoemulsification fluidics parameters to be sure the effects we observed were due to intracameral phenylephrine. The use of OVDs such as Healon5 coupled with slow-motion fluidics has been advocated by some.1,9 We intend to study the use of such less aggressive fluidics to determine whether alteration of phaco parameters will make the procedure safer. The recently introduced torsional phaco modality on the Infiniti Lens System (Alcon Laboratories) provides low repulsion, high-efficiency characteristics that could be beneficial in IFIS. As a result of our experience with this large series, we propose the following interim algorithm to manage IFIS patients. More than half (53%) will have a large pupil at the outset. About half these pupils will constrict during surgery; intracameral phenylephrine will redilate the pupil to its original size and reduce or prevent prolapse. Thirty-eight percent will have a mid-dilated pupil. Although intracameral phenylephrine at the outset will not necessarily enlarge most, it will prevent further constriction or will redilate the pupil moderately. Approximately 9% will have a small pupil, and if the surgeon is experienced with small pupils,
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006
1613
CATARACT SURGERY IN PATIENTS TAKING TAMSULOSIN
intracameral phenylephrine may allow safe surgery without the use of hooks or pupil expanders. Although we have no direct proof that the use of intracameral phenylephrine led to an absence of IFIS-related complications in this large series, we believe that the evidence of redilation of the pupils that constricted during surgery and the cessation of observed iris prolapse after using intracameral phenylephrine are powerful arguments for the effectiveness of this intervention. REFERENCES 1. Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg 2005; 31:664–673 2. Hawrylyshyn KA, Michelotti GA, Coge´ F, et al. Update on human a1adrenoceptor subtype signaling and genomic organization. Trends Pharmacol Sci 2004; 25:449–455
1614
3. Schwinn DA, Price DT, Narayan P. a1-adrenoceptor subtype selectivity and lower urinary tract symptoms. Mayo Clinic Proc 2004; 79:1423– 1434 4. Yu Y, Koss MC. a1A-adrenoceptors mediate sympathetically evoked pupillary dilation in rats. J Pharmacol Exp Ther 2002; 300:521–525 5. Lundberg B, Behndig A. Intracameral mydriatics in phacoemulsification cataract surgery. J Cataract Refract Surg 2003; 29:2366–2371 6. Schwinn DA, Afshari NA. a1-adrenergic antagonists and floppy iris syndrome: tip of the iceberg? [editorial] Ophthalmology 2005; 112:2059– 2060 7. Gurbaxani A, Packard R. Intracameral phenylephrine to prevent floppy iris syndrome during cataract surgery in patients on tamsulosin. Eye advance online publication, November 11, 2005. Available at: http://www.nature.com/eye/journal/vaop/ncurrent/abs/6702172a.html. Accessed April 1, 2006 8. Lowe FC. Role of the newer alpha1-adrenergic-receptor antagonists in the treatment of benign prostatic hyperplasia-related lower urinary tract symptoms. Clin Ther 2004; 26:1701–1713 9. Osher RH. Association between IFIS and Flomax. J Cataract Refract Surg 2006; 32:547
J CATARACT REFRACT SURG - VOL 32, OCTOBER 2006