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Small-gauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification
LETTERS
photorefractive keratectomy. Arch Ophthalmol 2002; 120: 896–900 2. Kawana K, Tokumaga T, Miyata K, et al. Comparison of corneal thickness measurements using Orbscan II, noncontact specular microscopy, and ultrasonic pachymetry in eyes after laser in situ keratomileusis. Br J Ophthalmol 2004; 88:466–468
Pseudophakic preoperative maculopathy
T
he hypothesis proposed by Miyake et al.1 for the development of pseudophakic preservative maculopathy opens a Pandora’s box with regard to postoperative management after cataract surgery. They have suggested that the preservative benzalkonium chloride in antiglaucoma medications contributes to the development of postoperative cystoid macular edema (CME). Almost all topical ocular antiinfective and antiinflammatory drugs routinely used after cataract surgery contain benzalkonium chloride as a preservative.2 Would they suggest use of preservative-free, single-use eyedrops (minims) to reduce the incidence of postoperative CME? This would considerably increase the cost of management. AMIT GAUR, MD, FRCS Sheffield, United Kingdom
References 1. Miyake K, Ibaraki N, Goto Y, et al. ESCRS Binkhourst Lecture 2002: Pseudophakic preservative maculopathy [special report]. J Cataract Refract Surg 2003; 29:1800– 1810 2. Duncan C. Monthly Index of Medical Specialties. London, Haymarket Medical Publications Ltd, 2002; 268
Reply:
We thank Dr. Gaur for his beneficial suggestions. In preliminary studies, we have confirmed increases in postoperative flare and the incidence of CME with other antimicrobials and allergy medications containing benzalkonium chloride. We also compared steroids with and without benzalkonium but found no significant difference between them in flare or incidence or CME. A multicenter study comparing nonsteroidal antiinflammatory drugs (NSAIDs) with and without benzalkonium is underway in Europe. Steroids and NSAIDs may suppress inflammatory signs induced by benzalkonium, and the combination of antiinflammatory agents and preservatives is an interesting problem involving special elements. However, it is important that as a general rule, postoperative eyedrops be made preservative free.—Kensaku Miyake, MD 2252
Small-gauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification
I
n the article by Chalam and coauthors,1 small-gauge, sutureless pars plana vitrectomy was used to manage vitreous loss during phacoemulsification. They found their 25-gauge pars plana technique more effective than the anterior approach for cleaning of the vitreous from the corneal wound and anterior chamber. The authors stated that this approach eliminates complications encountered during or after surgery, such as suprachoroidal hemorrhage, retinal detachment, and cystoid macular edema. I want to make some points related to this article. The authors used a 25-gauge pars plana anterior vitrectomy to clean the vitreous and sometimes remove residual cortical material with or without epinucleus from the anterior chamber. Whether you use a 20- or 25-gauge cannula, I think it is difficult to completely clean all vitreous from the anterior chamber this way. The authors say the vitreous was pushed back toward the posterior chamber and away from the corneal wound by anterior chamber irrigation. They also state that the residual vitreous strands were moved far away from the corneal wound by a sweeping movement with a spatula. I have 2 objections to this; first, you cannot push the anterior vitreous completely back to the posterior chamber by only simple irrigation without complete anterior vitrectomy. The vitreous will hydrate by irrigation, depending on the irrigation amount, as mentioned in the article. My second objection is related to the cleaning of the vitreous strands with the spatula from the corneal wound. Again, this cleaning is impossible without anterior vitrectomy using a corneal or scleral approach. The pars plana approach does not provide enough distance for cleaning the vitreous in the anterior chamber and corneal wound comfortably. Chalam and coauthors state if the posterior capsule tear is too small, a 25-gauge cutter is placed through the side port for removing the vitreous in the anterior chamber. My opinion is the 25-gauge system is a good option to clean the vitreous from the anterior chamber and corneal wound without enlarging the wound size. However, I do not agree with the authors that the
J CATARACT REFRACT SURG—VOL 30, NOVEMBER 2004
LETTERS
traditional vitrectors do not have enough capacity for anterior chamber cleaning. I think the pars plana approach is not a reasonable idea for anterior vitrectomy because the pars plana entry has the risk for iatrogenic tears in the peripheral retina. The 25-gauge sutureless approach is a new, less invasive, and promising system for posterior vitrectomy. However, it has some limitations and potential complications. One potential complication is postoperative hypotony. Hypotony is the major stimulating factor for intraocular hemorrhages and other secondary complications. Again, I do not agree with the authors that the 25-gauge system will eliminate the chance of suprachoroidal hemorrhage. Vitreous loss during anterior surgery, including phacoemulsification, leads to hypotony. Using a 25-gauge sutureless system from the pars plana for anterior vitreous cleaning might increase postoperative hypotony and other complications. As I said, the 25-gauge sutureless system is a good development for posterior vitrectomy, but it has drawbacks such as the risk for potential endophthalmitis because of leakage from sclerotomy sites. The risk for postoperative hypotony and intraocular hemorrhages remains. No one wants to encounter these unwanted complications after cataract surgery. I agree with the authors that using a 25-gauge system from the corneal or scleral wound site to perform anterior vitrectomy has additional positive advantages, but I do not think the pars plana approach is a good option for anterior cleanup of the vitreous. HAMDI ER, MD Malatya, Turkey
Reference 1. Chalam KV, Gupta SK, Vinjamaram S, Shah VA. Smallgauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification. J Cataract Refract Surg 2003; 29:1482–1486
Reply:
We appreciate Dr. Er’s interest in the subject and our article. He has interesting observations and thoughts about the technique. However, we disagree with some of his comments. We want to clarify the use of an iris spatula and anterior infusion in this technique. The iris spatula is introduced through the anterior chamber side port after the wound is secured with a 10-0 suture. The spatula sweeps the incarcerated vitreous away from the corneal incision, making it free from the vitreous.
Reincarceration of vitreous in the wound is prevented as the eye is a closed system at this juncture. An anterior infusion placed through the opposite side port pushes the vitreous back toward the posterior. Regarding the accessibility of the pars plana approach, we strongly believe that it offers better accessibility for the vitreous in and around the corneal incision. With the regular anterior vitrectomy probe, it is difficult to address the vitreous around the corneal incision, as the eye is not a closed system. Thus, the vitreous tends to hydrate and prolapse anteriorly during removal. We agree with Dr. Er’s concerns regarding the risk for retinal tears from the pars plana approach. Histological studies did not reveal abnormal vitreous adhesions at the wound in small-gauge sclerotomies with normal intraocular pressure. This minimizes sclerotomy-related complications.1 In our small series of 29 patients, we have not found such complications (V.A. Shah, MD, and coauthors, “Successful Management of Cataract SurgeryAssociated Vitreous Loss with Sutureless Small-Gauge Pars Plana Vitrectomy,” presented at the American Academy of Ophthalmology annual meeting, Anaheim, California, USA, November 2003). We do examine the retina and the sclerotomy site with an indirect ophthalmoscope after surgery is finished. Postoperative hypotony and endophthalmitis are theoretical concerns with sutureless sclerotomies. However, in our series, we did not have these complications (V.A. Shah, MD, and coauthors, “Successful Management of Cataract Surgery-Associated Vitreous Loss with Sutureless Small-Gauge Pars Plana Vitrectomy,” presented at the American Academy of Ophthalmology annual meeting, Anaheim, California, USA, November 2003). We move the conjunctiva superiorly before introducing the 25-gauge trocar and cannula initially. Upon removal of the trocar, the conjunctival wound is not aligned with the scleral wound, thus preventing a continuous track for fluid egress or bacterial influx.—K.V. Chalam, MD
Reference 1. Fujii GY, De Juan E Jr, Humayun MS, et al. A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery. Ophthalmology 2002; 109: 1807–1812; discussion, 1813; erratum, 2003; 110:9
Effect of diclofenac versus dexamethasone on posterior capsule opacification
I
n their article, Zaczek and coauthors1 report that topical instillation of diclofenac or dexamethasone in the immediate postoperative period after phacoemulsification had no influence on posterior capsule opacification (PCO) formation 2 years postoperatively.
J CATARACT REFRACT SURG—VOL 30, NOVEMBER 2004
2253
photorefractive keratectomy. Arch Ophthalmol 2002; 120: 896–900 2. Kawana K, Tokumaga T, Miyata K, et al. Comparison of corneal thickness measurements using Orbscan II, noncontact specular microscopy, and ultrasonic pachymetry in eyes after laser in situ keratomileusis. Br J Ophthalmol 2004; 88:466–468
Pseudophakic preoperative maculopathy
T
he hypothesis proposed by Miyake et al.1 for the development of pseudophakic preservative maculopathy opens a Pandora’s box with regard to postoperative management after cataract surgery. They have suggested that the preservative benzalkonium chloride in antiglaucoma medications contributes to the development of postoperative cystoid macular edema (CME). Almost all topical ocular antiinfective and antiinflammatory drugs routinely used after cataract surgery contain benzalkonium chloride as a preservative.2 Would they suggest use of preservative-free, single-use eyedrops (minims) to reduce the incidence of postoperative CME? This would considerably increase the cost of management. AMIT GAUR, MD, FRCS Sheffield, United Kingdom
References 1. Miyake K, Ibaraki N, Goto Y, et al. ESCRS Binkhourst Lecture 2002: Pseudophakic preservative maculopathy [special report]. J Cataract Refract Surg 2003; 29:1800– 1810 2. Duncan C. Monthly Index of Medical Specialties. London, Haymarket Medical Publications Ltd, 2002; 268
Reply:
We thank Dr. Gaur for his beneficial suggestions. In preliminary studies, we have confirmed increases in postoperative flare and the incidence of CME with other antimicrobials and allergy medications containing benzalkonium chloride. We also compared steroids with and without benzalkonium but found no significant difference between them in flare or incidence or CME. A multicenter study comparing nonsteroidal antiinflammatory drugs (NSAIDs) with and without benzalkonium is underway in Europe. Steroids and NSAIDs may suppress inflammatory signs induced by benzalkonium, and the combination of antiinflammatory agents and preservatives is an interesting problem involving special elements. However, it is important that as a general rule, postoperative eyedrops be made preservative free.—Kensaku Miyake, MD 2252
Small-gauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification
I
n the article by Chalam and coauthors,1 small-gauge, sutureless pars plana vitrectomy was used to manage vitreous loss during phacoemulsification. They found their 25-gauge pars plana technique more effective than the anterior approach for cleaning of the vitreous from the corneal wound and anterior chamber. The authors stated that this approach eliminates complications encountered during or after surgery, such as suprachoroidal hemorrhage, retinal detachment, and cystoid macular edema. I want to make some points related to this article. The authors used a 25-gauge pars plana anterior vitrectomy to clean the vitreous and sometimes remove residual cortical material with or without epinucleus from the anterior chamber. Whether you use a 20- or 25-gauge cannula, I think it is difficult to completely clean all vitreous from the anterior chamber this way. The authors say the vitreous was pushed back toward the posterior chamber and away from the corneal wound by anterior chamber irrigation. They also state that the residual vitreous strands were moved far away from the corneal wound by a sweeping movement with a spatula. I have 2 objections to this; first, you cannot push the anterior vitreous completely back to the posterior chamber by only simple irrigation without complete anterior vitrectomy. The vitreous will hydrate by irrigation, depending on the irrigation amount, as mentioned in the article. My second objection is related to the cleaning of the vitreous strands with the spatula from the corneal wound. Again, this cleaning is impossible without anterior vitrectomy using a corneal or scleral approach. The pars plana approach does not provide enough distance for cleaning the vitreous in the anterior chamber and corneal wound comfortably. Chalam and coauthors state if the posterior capsule tear is too small, a 25-gauge cutter is placed through the side port for removing the vitreous in the anterior chamber. My opinion is the 25-gauge system is a good option to clean the vitreous from the anterior chamber and corneal wound without enlarging the wound size. However, I do not agree with the authors that the
J CATARACT REFRACT SURG—VOL 30, NOVEMBER 2004
LETTERS
traditional vitrectors do not have enough capacity for anterior chamber cleaning. I think the pars plana approach is not a reasonable idea for anterior vitrectomy because the pars plana entry has the risk for iatrogenic tears in the peripheral retina. The 25-gauge sutureless approach is a new, less invasive, and promising system for posterior vitrectomy. However, it has some limitations and potential complications. One potential complication is postoperative hypotony. Hypotony is the major stimulating factor for intraocular hemorrhages and other secondary complications. Again, I do not agree with the authors that the 25-gauge system will eliminate the chance of suprachoroidal hemorrhage. Vitreous loss during anterior surgery, including phacoemulsification, leads to hypotony. Using a 25-gauge sutureless system from the pars plana for anterior vitreous cleaning might increase postoperative hypotony and other complications. As I said, the 25-gauge sutureless system is a good development for posterior vitrectomy, but it has drawbacks such as the risk for potential endophthalmitis because of leakage from sclerotomy sites. The risk for postoperative hypotony and intraocular hemorrhages remains. No one wants to encounter these unwanted complications after cataract surgery. I agree with the authors that using a 25-gauge system from the corneal or scleral wound site to perform anterior vitrectomy has additional positive advantages, but I do not think the pars plana approach is a good option for anterior cleanup of the vitreous. HAMDI ER, MD Malatya, Turkey
Reference 1. Chalam KV, Gupta SK, Vinjamaram S, Shah VA. Smallgauge, sutureless pars plana vitrectomy to manage vitreous loss during phacoemulsification. J Cataract Refract Surg 2003; 29:1482–1486
Reply:
We appreciate Dr. Er’s interest in the subject and our article. He has interesting observations and thoughts about the technique. However, we disagree with some of his comments. We want to clarify the use of an iris spatula and anterior infusion in this technique. The iris spatula is introduced through the anterior chamber side port after the wound is secured with a 10-0 suture. The spatula sweeps the incarcerated vitreous away from the corneal incision, making it free from the vitreous.
Reincarceration of vitreous in the wound is prevented as the eye is a closed system at this juncture. An anterior infusion placed through the opposite side port pushes the vitreous back toward the posterior. Regarding the accessibility of the pars plana approach, we strongly believe that it offers better accessibility for the vitreous in and around the corneal incision. With the regular anterior vitrectomy probe, it is difficult to address the vitreous around the corneal incision, as the eye is not a closed system. Thus, the vitreous tends to hydrate and prolapse anteriorly during removal. We agree with Dr. Er’s concerns regarding the risk for retinal tears from the pars plana approach. Histological studies did not reveal abnormal vitreous adhesions at the wound in small-gauge sclerotomies with normal intraocular pressure. This minimizes sclerotomy-related complications.1 In our small series of 29 patients, we have not found such complications (V.A. Shah, MD, and coauthors, “Successful Management of Cataract SurgeryAssociated Vitreous Loss with Sutureless Small-Gauge Pars Plana Vitrectomy,” presented at the American Academy of Ophthalmology annual meeting, Anaheim, California, USA, November 2003). We do examine the retina and the sclerotomy site with an indirect ophthalmoscope after surgery is finished. Postoperative hypotony and endophthalmitis are theoretical concerns with sutureless sclerotomies. However, in our series, we did not have these complications (V.A. Shah, MD, and coauthors, “Successful Management of Cataract Surgery-Associated Vitreous Loss with Sutureless Small-Gauge Pars Plana Vitrectomy,” presented at the American Academy of Ophthalmology annual meeting, Anaheim, California, USA, November 2003). We move the conjunctiva superiorly before introducing the 25-gauge trocar and cannula initially. Upon removal of the trocar, the conjunctival wound is not aligned with the scleral wound, thus preventing a continuous track for fluid egress or bacterial influx.—K.V. Chalam, MD
Reference 1. Fujii GY, De Juan E Jr, Humayun MS, et al. A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery. Ophthalmology 2002; 109: 1807–1812; discussion, 1813; erratum, 2003; 110:9
Effect of diclofenac versus dexamethasone on posterior capsule opacification
I
n their article, Zaczek and coauthors1 report that topical instillation of diclofenac or dexamethasone in the immediate postoperative period after phacoemulsification had no influence on posterior capsule opacification (PCO) formation 2 years postoperatively.
J CATARACT REFRACT SURG—VOL 30, NOVEMBER 2004
2253