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Retinal detachment prophylaxis
Letters to the Editor ing this out. The false positive rate should be how many times a normal patient is called disease (with specificity being one minus the false positive rate) and the false negative rate should be how often a patient with disease is called normal (with sensitivity being one minus the false negative rate). These definitions are appropriate for studies in which cut-off values of single parameters are used in an attempt to discriminate between groups. Given that this was a clinical study in which masked observers were asked to make assessments of pooled printouts using no set criteria, we defined our rates with regards to the entire pool, and these definitions appear in the paper. In other words, we defined false positives in terms of how many times a printout was incorrectly identified as abnormal and a false negative as how many times a printout from an abnormal eye was called normal, within the context of the entire pool. Table 5 does use the more conventional definitions, with elimination of glaucoma suspects to reduce diagnostic confusion. The demonstrated specificity was 79% with a sensitivity of 92%. NEIL T. CHOPLIN, MD DIANE C. LUNDY, MD San Diego, California
Retinal Detachment Prophylaxis Dear Editor: We congratulate Dr. Wilkinson for his very interesting article assessing the quality of information in the literature regarding the benefits of prophylactic treatment of asymptomatic retinal tears and lattice degeneration.1 We believe that the topic of retinal detachment (RD) prophylaxis is still controversial and the lack of prospective randomized trials of therapy does not facilitate our clinical choice. Byer recommends study of the occurrence of posterior vitreous detachment (PVD) as the crisis event that is basic and mandatory to test the effect of treatment in any prospective long-range study.2 Hovland’s study3 can be considered a milestone on the role of PVD in determining RD. As stated by Wilkinson, the vitreous gel plays an important role in the pathogenesis of future RD, but the PVD variable has not been included in any other published study known to the Preferred Practice Pattern Panel regarding prophylactic therapy.1 In our prospective study of treatment of retinal tears and lattice degenerations in fellow eyes in high-risk patients suffering RD,4 we determined the state of the vitreous body at the beginning of the study and during follow-up, using both biomicroscopic and ultrasonic criteria. The progression of PVD in most of the eyes which developed fellow eye RD was the most interesting finding. In our sample, 17 of 18 patients who developed fellow eye RD showed an evident progression of PVD. Ten eyes had been subjected to laser treatment. In five of them (50% of cases), a partial PVD had progressed and RD was linked to new retinal tears in previously healthy areas. The presence of symptomatic retinal lesions is widely accepted to be the foremost indication for treatment, but sometimes the mere recognition and treatment of risk areas in the fellow eye are not enough to prevent a further devel-
opment of this pathology, which seems also to be linked to PVD developing. Some eyes with preexisting retinal breaks and partial PVD can go on to RD, despite laser treatment. When PVD is not detectable or a partial PVD has not yet progressed to a complete PVD, the possibility that retinal tears and RDs arise in areas which show no visible retinal abnormalities has to be strongly considered. In fact, in an unknown portion of the population there exist pathological vitreoretinal adhesions, most of which are not visible clinically or discoverable;5 undetectable vitreoretinal adhesions become translated into vitreoretinal tractions at the time of PVD. In our study4 in some selected cases a silicone encircling band and scleral buckle were preferred. This method is able to reduce peripheral vitreoretinal traction and can be reserved for eyes with multiple retinal degenerations larger than 90°, retinal dialysis, giant tears, multiple retinal tears in several quadrants, or large tears that had either rolled edges (PVR, stage B) or localized subretinal fluid surrounding the tear (subclinical RD). In conclusion, according to Byer we believe that any table containing recommendations for prophylactic therapy for prevention of RD must include the state of the vitreous body among the clinical conditions to be evaluated. The vitreous body can be considered “the silent protagonist in the drama called retinal detachment.” PAOLO CARPINETO, MD MARCO CIANCAGLINI, MD LEONARDO MASTROPASQUA, MD Chieti, Italy References 1. Wilkinson CP. Evidence-based analysis of prophylactic treatment of asymptomatic retinal breaks and lattice degeneration. Ophthalmology 2000;107:12–5; discussion 15– 8. 2. Byer NE. Discussion. Ophthalmology 2000;107:15– 6. 3. Hovland KR. Vitreous findings in fellow eyes of aphakic retinal detachment. Am J Ophthalmol 1978;86:350 –3. 4. Mastropasqua L, Carpineto P, Ciancaglini M, et al. Treatment of retinal tears and lattice degenerations in fellow eyes in high risk patients suffering retinal detachment: a prospective study. Br J Ophthalmol 1999;83:1046 –9. 5. Byer NE. Author Reply. Ophthalmology 1995;102:527– 8.
Author reply Dear Editor: Thanks to Dr. Carpineto and his co-responders for reemphasizing the importance of vitreous traction upon invisible sites of vitroretinal adhesions and the development of retinal tears at such locations. I agree that the status of the vitreous gel is a critical variable in any discussion of prophylactic therapy, and it is unfortunate that appropriate trials have not yet been conducted. The important article to which they refer1 demonstrated that eyes with partial posterior vitreous detachments (PVDs) remain at risk for future vitreoretinal traction and retinal tears. However, making the diagnosis of a partial PVD can be very difficult, and the perplexing problems of how to treat “invisible” vitreoretinal adhesions and to document the value of such therapy continue to be sources of debate.
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Retinal Detachment Prophylaxis Dear Editor: We congratulate Dr. Wilkinson for his very interesting article assessing the quality of information in the literature regarding the benefits of prophylactic treatment of asymptomatic retinal tears and lattice degeneration.1 We believe that the topic of retinal detachment (RD) prophylaxis is still controversial and the lack of prospective randomized trials of therapy does not facilitate our clinical choice. Byer recommends study of the occurrence of posterior vitreous detachment (PVD) as the crisis event that is basic and mandatory to test the effect of treatment in any prospective long-range study.2 Hovland’s study3 can be considered a milestone on the role of PVD in determining RD. As stated by Wilkinson, the vitreous gel plays an important role in the pathogenesis of future RD, but the PVD variable has not been included in any other published study known to the Preferred Practice Pattern Panel regarding prophylactic therapy.1 In our prospective study of treatment of retinal tears and lattice degenerations in fellow eyes in high-risk patients suffering RD,4 we determined the state of the vitreous body at the beginning of the study and during follow-up, using both biomicroscopic and ultrasonic criteria. The progression of PVD in most of the eyes which developed fellow eye RD was the most interesting finding. In our sample, 17 of 18 patients who developed fellow eye RD showed an evident progression of PVD. Ten eyes had been subjected to laser treatment. In five of them (50% of cases), a partial PVD had progressed and RD was linked to new retinal tears in previously healthy areas. The presence of symptomatic retinal lesions is widely accepted to be the foremost indication for treatment, but sometimes the mere recognition and treatment of risk areas in the fellow eye are not enough to prevent a further devel-
opment of this pathology, which seems also to be linked to PVD developing. Some eyes with preexisting retinal breaks and partial PVD can go on to RD, despite laser treatment. When PVD is not detectable or a partial PVD has not yet progressed to a complete PVD, the possibility that retinal tears and RDs arise in areas which show no visible retinal abnormalities has to be strongly considered. In fact, in an unknown portion of the population there exist pathological vitreoretinal adhesions, most of which are not visible clinically or discoverable;5 undetectable vitreoretinal adhesions become translated into vitreoretinal tractions at the time of PVD. In our study4 in some selected cases a silicone encircling band and scleral buckle were preferred. This method is able to reduce peripheral vitreoretinal traction and can be reserved for eyes with multiple retinal degenerations larger than 90°, retinal dialysis, giant tears, multiple retinal tears in several quadrants, or large tears that had either rolled edges (PVR, stage B) or localized subretinal fluid surrounding the tear (subclinical RD). In conclusion, according to Byer we believe that any table containing recommendations for prophylactic therapy for prevention of RD must include the state of the vitreous body among the clinical conditions to be evaluated. The vitreous body can be considered “the silent protagonist in the drama called retinal detachment.” PAOLO CARPINETO, MD MARCO CIANCAGLINI, MD LEONARDO MASTROPASQUA, MD Chieti, Italy References 1. Wilkinson CP. Evidence-based analysis of prophylactic treatment of asymptomatic retinal breaks and lattice degeneration. Ophthalmology 2000;107:12–5; discussion 15– 8. 2. Byer NE. Discussion. Ophthalmology 2000;107:15– 6. 3. Hovland KR. Vitreous findings in fellow eyes of aphakic retinal detachment. Am J Ophthalmol 1978;86:350 –3. 4. Mastropasqua L, Carpineto P, Ciancaglini M, et al. Treatment of retinal tears and lattice degenerations in fellow eyes in high risk patients suffering retinal detachment: a prospective study. Br J Ophthalmol 1999;83:1046 –9. 5. Byer NE. Author Reply. Ophthalmology 1995;102:527– 8.
Author reply Dear Editor: Thanks to Dr. Carpineto and his co-responders for reemphasizing the importance of vitreous traction upon invisible sites of vitroretinal adhesions and the development of retinal tears at such locations. I agree that the status of the vitreous gel is a critical variable in any discussion of prophylactic therapy, and it is unfortunate that appropriate trials have not yet been conducted. The important article to which they refer1 demonstrated that eyes with partial posterior vitreous detachments (PVDs) remain at risk for future vitreoretinal traction and retinal tears. However, making the diagnosis of a partial PVD can be very difficult, and the perplexing problems of how to treat “invisible” vitreoretinal adhesions and to document the value of such therapy continue to be sources of debate.
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