Reply

Abstract

We apologize for inadvertently failing to cite Dr. Ophir's published letter to the editor in Ophthalmology.1El-Dairi M.A. Holgado S. O'Donnell T. et al.Optical coherence tomography as a tool for monitoring pediatric pseudotumor cerebri.J AAPOS. 2007; 11: 564-570Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 2Ophir A. Karatas M. Ramirez J.A. et al.OCT and chronic papilledema.Ophthalmology. 2005; 112: 2238Abstract Full Text Full Text PDF PubMed Google Scholar We agree with Dr. Ophir that major differences between our 2 studies (detailed herein) may account for our differing results and conclusions. In contrast to the work of Dr. Ophir, our study was intended to be a pilot study in children with pseudotumor cerebri, an uncommon pediatric disease. Although we would ideally have included children with pseudotumor cerebri on initial presentation before any treatment, we only encounter approximately 5 new cases annually, most of whom are already diagnosed and receiving treatment. Moreover, children with newly diagnosed pseudotumor cerebri may have suffered with the condition for some time before diagnosis and may conceivably even have superimposed optic nerve head atrophy in the setting of persisting edema. Even in Dr. Ophir's adult series, 1 patient already reportedly demonstrated optic nerve atrophy at the time of diagnosis. Regarding the concern that hemorrhage or exudate might alter results of optical coherence tomography (OCT) measurement in our pediatric patients, it is important to note that all children in our study had optic nerve head swelling of grade 2 or less on the Frisén scale (mild-to-moderate swelling), and none of them had exudation or hemorrhages on clinical fundus examination. Differences in results between our study and Dr. Ophir's published work may well relate as much to different analysis techniques as to the data themselves. For example, Dr. Ophir's study included a single OCT protocol, the RNFL 3.4 protocol, and analysis was performed by the clock hour. The patients (vs controls) in Dr. Ophir's study demonstrated statistically significant difference in 8 contiguous clock hours (7 to 12), corresponding roughly to the temporal quadrant. In our study, we found significantly thicker retinal nerve fiber layer (RNFL) in 3 consecutive quadrants (superior, temporal, and inferior) among the eyes of children with pseudotumor cerebri; however, only thickening in the inferior quadrant remained statistically significant after Bonferroni correction for multiple comparisons (a statistical correction not mentioned in Dr. Ophir's letter to the editor). In addition to the RNFL 3.4 protocol, each eye in our study underwent the RNFL map protocol; we reported that swollen optic nerves caused by pseudotumor cerebri had thickened RNFL in the temporal inner quadrant (scan area at an average of 2.9 mm in diameter, roughly close to the 3.4 diameter used in the RNFL 3.4 protocol), a finding which consistent with that of Dr. Ophir. Finally, our finding of thickened macula in eyes with pseudotumor cerebri (vs control eyes) is of greatest interest from our point of view because the fast macula protocol is more easily performed (and more reproducible) than other OCT protocols, especially in children.3Wang X.Y. Huynh S.C. Burlutsky G. et al.Reproducibility of and effect of magnification on optical coherence tomography measurements in children.Am J Ophthalmol. 2007; 143: 484-488Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar We concluded from our pilot study that it is feasible to use OCT for monitoring optic nerve swelling due to pseudotumor cerebri in children, most of whom are unable to provide reliable visual field testing. We acknowledge that a larger clinical series with long-term follow-up will be necessary to validate the utility of OCT as a standard technology for use in clinical management of children with papilledema and pseudotumor cerebri. Optical coherence tomography as an adjunctive tool for diagnosing pediatric pseudotumor cerebriJournal of American Association for Pediatric Ophthalmology and Strabismus {JAAPOS}Vol. 12Issue 4PreviewEl-Dairi et al1 reported on the beneficial use of optical coherence tomography (OCT) in children with pseudotumor cerebri (idiopathic intracranial hypertension [IIH]). When the authors used the circumpapillary retinal nerve fiber layer (RNFL) 3.4 mm diameter protocol on eyes with papilledema (n = 16 eyes), the RNFL was significantly thicker than that of normal controls (n = 37) in the inferior quadrant and in the total RNFL average. Of interest, when a smaller, 3 mm in diameter circular OCT scan was used (n = 18 eyes), the RNFL was significantly thicker than that of the controls at other sites, that is, in the superior and temporal quadrants. Full-Text PDF