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Other Considerations in Pterygium Surgery
Ophthalmology Volume 120, Number 9, Month 2013
Other Considerations in Pterygium Surgery Dear Editor: The Ophthalmic Technology Assessment (OTA)1 is a valuable and timely assessment of the techniques that might be used for pterygium surgery and focusses attention on 2 aspects of pterygium surgery, namely recurrence rates and complications of the various techniques through review of randomized, controlled trials. There are some concerns with respect to the design of this study. In approximately one third of the primary pterygium studies (Table 1A),1 the definition of recurrence was >1 mm onto the cornea. This is not the usual definition and significantly underestimates a true recurrence as defined by most clinicians, so that, although there may be comparability between the 2 arms of most of these studies, it does not reflect true recurrence rate. If this is to be used by practicing ophthalmologists to guide their pterygium surgery, which I understand is the purpose of an OTA, then caution should be applied to the conclusions drawn for the following reasons. First, “Evidence indicates that bare sclera excision of pterygium results in a significantly higher recurrence rate than excision accompanied by use of certain adjuvants.” The literature reviewed by the authors indicate that in 13 studies using bare sclera as 1 arm of a randomized, controlled trial (Table 1A)1 the average recurrence rate of this technique was nearly 50% (range, 27%e88%). Although this statement indicates an increased recurrence rate for this method, it does not mention that 1 in 2 patients will have recurrence. Despite the obvious conclusion that “legal counsel” may have advised against any definitive statement, it is time that someone took a stand against this totally ineffective treatment and this opportunity was sadly missed in the OTA. Second, “Among other adjuvants, there is evidence that mitomycin C and conjunctival or limbal autografts reduce the recurrence rate after surgical excision of a pterygium. Furthermore, the data indicate that using a combination of conjunctival or limbal autograft with mitomycin C further reduces the recurrence rate after pterygium excision compared with conjunctival or limbal autograft or mitomycin C alone.” Although the authors go on to say that “Additional studies are necessary to determine the longterm effects, optimal route of administration, and dose and duration of treatment for mitomycin C,” the entire thrust of this OTA is that mitomycin is an acceptable adjuvant. Although the authors show that mitomycin does decrease recurrence compared with bare sclera in primary pterygium (Table 1A), there is only 1 study using a free conjunctival autograft with mitomycin (excluding sliding conjunctival grafts) based on 30 patients with a recurrence rate of 0%. In 15 studies in which 1 arm was a free conjunctival graft alone the average recurrence rate was 10%. Not only is a study with 30 patients unlikely to reflect the true recurrence rate, but the authors risk advising the use of mitomycin plus a free graft rather than a free graft alone on the basis of this 1 study, although the literature is replete with publications where mitomycin has been documented to be associated with blindness and even in this review, scleromalacia ranges from 2% to 19%. However, this review does not document the frequency of publications that enumerate the multitude of complications of mitomycin. Clinical judgment suggests that, if there is a treatment that does not risk
e60
loss of all vision even if the recurrence may be slightly higher, this treatment should be used rather than one (mitomycin) that may reduce recurrence but brings with it significant complications. I fully understand that this OTA has reviewed only randomized, controlled trials; however, I would like to have seen a suggestion that a recently described technique, which has resulted in a recurrence rate of 1 in 1000 in an open, prospective study,2 would be used in future randomized, controlled trials because it has the best results in the world’s literature and should be the benchmark against which other methods are compared. This new method, which is a major modification of conjunctival autografting, has not been subjected to a randomized, controlled trial by this author because I cannot ethically use another method as comparison, all of which are, to my mind, inferior. However, other researchers would not suffer from the same limitations in using this method as 1 arm of a randomized, controlled trial. This technique was not mentioned in the OTA as the best comparator for subsequent randomized, controlled trials, which the authors have stated as necessary to better understand all techniques.
LAWRENCE W. HIRST, MD, MPH CEO, The Australian Pterygium Centre, Faculty, Queensland Eye Institute, University of Queensland, Brisbane, Australia Financial Disclosure: The author owns the trademark P.E.R.F.E.C.T. for PTERYGIUM.
References 1. Kaufman SC, Jacobs DS, Lee WB, et al. Options and adjuvants in surgery for pterygium. Ophthalmology 2013;120:201–8. 2. Hirst LW. Recurrence and complications after 1000 surgeries using pterygium extended removal followed by extended conjunctival transplant. Ophthalmology 2012;119:2205–10.
Author reply Dear Editor: We appreciate the comments and observations made by Dr. Hirst. We also acknowledge and thank him for his excellent contributions to the literature on pterygium surgical techniques and outcomes, including the description of his technique referred to as Pterygium Extended Removal Followed by Extended Conjunctival Transplant, which he has coined as P.E.R.F.E.C.T. Before we comment on Dr. Hirst’s compelling letter, let us review the purpose of the Ophthalmic Technology Assessment Committee (OTAC) in reference to his comments. The primary charge of the OTAC is to review systematically the peer-reviewed literature for clinical efficacy and safety of a particular procedure, drug, or diagnostic test. After review by members of the OTAC, other Academy committees, relevant subspecialty societies, and legal counsel, assessments are submitted to the Academy’s Board of Trustees for consideration as official Academy statements. The purpose of the assessment in question was to evaluate results from randomized, controlled trials published in the English-language literature on the outcomes and safety of current surgical options and adjuvants in the treatment of primary and recurrent pterygium.1 By definition, the review in this setting does not comment on case reports, retrospective studies, or prospective studies without
Other Considerations in Pterygium Surgery Dear Editor: The Ophthalmic Technology Assessment (OTA)1 is a valuable and timely assessment of the techniques that might be used for pterygium surgery and focusses attention on 2 aspects of pterygium surgery, namely recurrence rates and complications of the various techniques through review of randomized, controlled trials. There are some concerns with respect to the design of this study. In approximately one third of the primary pterygium studies (Table 1A),1 the definition of recurrence was >1 mm onto the cornea. This is not the usual definition and significantly underestimates a true recurrence as defined by most clinicians, so that, although there may be comparability between the 2 arms of most of these studies, it does not reflect true recurrence rate. If this is to be used by practicing ophthalmologists to guide their pterygium surgery, which I understand is the purpose of an OTA, then caution should be applied to the conclusions drawn for the following reasons. First, “Evidence indicates that bare sclera excision of pterygium results in a significantly higher recurrence rate than excision accompanied by use of certain adjuvants.” The literature reviewed by the authors indicate that in 13 studies using bare sclera as 1 arm of a randomized, controlled trial (Table 1A)1 the average recurrence rate of this technique was nearly 50% (range, 27%e88%). Although this statement indicates an increased recurrence rate for this method, it does not mention that 1 in 2 patients will have recurrence. Despite the obvious conclusion that “legal counsel” may have advised against any definitive statement, it is time that someone took a stand against this totally ineffective treatment and this opportunity was sadly missed in the OTA. Second, “Among other adjuvants, there is evidence that mitomycin C and conjunctival or limbal autografts reduce the recurrence rate after surgical excision of a pterygium. Furthermore, the data indicate that using a combination of conjunctival or limbal autograft with mitomycin C further reduces the recurrence rate after pterygium excision compared with conjunctival or limbal autograft or mitomycin C alone.” Although the authors go on to say that “Additional studies are necessary to determine the longterm effects, optimal route of administration, and dose and duration of treatment for mitomycin C,” the entire thrust of this OTA is that mitomycin is an acceptable adjuvant. Although the authors show that mitomycin does decrease recurrence compared with bare sclera in primary pterygium (Table 1A), there is only 1 study using a free conjunctival autograft with mitomycin (excluding sliding conjunctival grafts) based on 30 patients with a recurrence rate of 0%. In 15 studies in which 1 arm was a free conjunctival graft alone the average recurrence rate was 10%. Not only is a study with 30 patients unlikely to reflect the true recurrence rate, but the authors risk advising the use of mitomycin plus a free graft rather than a free graft alone on the basis of this 1 study, although the literature is replete with publications where mitomycin has been documented to be associated with blindness and even in this review, scleromalacia ranges from 2% to 19%. However, this review does not document the frequency of publications that enumerate the multitude of complications of mitomycin. Clinical judgment suggests that, if there is a treatment that does not risk
e60
loss of all vision even if the recurrence may be slightly higher, this treatment should be used rather than one (mitomycin) that may reduce recurrence but brings with it significant complications. I fully understand that this OTA has reviewed only randomized, controlled trials; however, I would like to have seen a suggestion that a recently described technique, which has resulted in a recurrence rate of 1 in 1000 in an open, prospective study,2 would be used in future randomized, controlled trials because it has the best results in the world’s literature and should be the benchmark against which other methods are compared. This new method, which is a major modification of conjunctival autografting, has not been subjected to a randomized, controlled trial by this author because I cannot ethically use another method as comparison, all of which are, to my mind, inferior. However, other researchers would not suffer from the same limitations in using this method as 1 arm of a randomized, controlled trial. This technique was not mentioned in the OTA as the best comparator for subsequent randomized, controlled trials, which the authors have stated as necessary to better understand all techniques.
LAWRENCE W. HIRST, MD, MPH CEO, The Australian Pterygium Centre, Faculty, Queensland Eye Institute, University of Queensland, Brisbane, Australia Financial Disclosure: The author owns the trademark P.E.R.F.E.C.T. for PTERYGIUM.
References 1. Kaufman SC, Jacobs DS, Lee WB, et al. Options and adjuvants in surgery for pterygium. Ophthalmology 2013;120:201–8. 2. Hirst LW. Recurrence and complications after 1000 surgeries using pterygium extended removal followed by extended conjunctival transplant. Ophthalmology 2012;119:2205–10.
Author reply Dear Editor: We appreciate the comments and observations made by Dr. Hirst. We also acknowledge and thank him for his excellent contributions to the literature on pterygium surgical techniques and outcomes, including the description of his technique referred to as Pterygium Extended Removal Followed by Extended Conjunctival Transplant, which he has coined as P.E.R.F.E.C.T. Before we comment on Dr. Hirst’s compelling letter, let us review the purpose of the Ophthalmic Technology Assessment Committee (OTAC) in reference to his comments. The primary charge of the OTAC is to review systematically the peer-reviewed literature for clinical efficacy and safety of a particular procedure, drug, or diagnostic test. After review by members of the OTAC, other Academy committees, relevant subspecialty societies, and legal counsel, assessments are submitted to the Academy’s Board of Trustees for consideration as official Academy statements. The purpose of the assessment in question was to evaluate results from randomized, controlled trials published in the English-language literature on the outcomes and safety of current surgical options and adjuvants in the treatment of primary and recurrent pterygium.1 By definition, the review in this setting does not comment on case reports, retrospective studies, or prospective studies without