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Increased Prevalence of Occludable Angles and Angle-closure Glaucoma in Patients With Pseudoexfoliation
540
October, 1994
AMERICAN JOURNAL OF OPHTHALMOLOGY
test, and the American Optical Vectograph using the 20/40 line. The four outcome groups were based on the postoperative motor and sensor functions. These sensory results, al though not specifically mentioned in our re port, were part of the definition of the four outcome groups as described by von Noorden. This article defines the criteria for success as determination of stability of visual acuity, whether further surgery was required and out come group classification status changed. We thank Drs. Arthur and Scott for their queries into the results and the rationale of our group ing. With this particular classification schema, separation of outcome groups 1 and 2 appears to be relevant. YAACOV SHAULY, M.D. THOMAS C. PRAGER, Ph.D. MALCOLM L. MAZOW, M.D.
Houston, Texas
Increased Prevalence of Occludable Angles and Angle-closure Glaucoma in Patients With Pseudoexfoliation EDITOR:
In the article, "Increased prevalence of oc cludable angles and angle-closure glaucoma in patients with pseudoexfoliation," by F. J. Gross, D. Tingey, and D. L. Epstein (Am. J. Ophthalmol. 117:333, March 1994), we sup port the authors' findings. We believe that these findings are important, and more than speculative. In a previous study 1 we described 149 pa tients with pseudoexfoliation glaucoma. We found an even higher prevalence of such cases. Indeed, 21.5% of the examined eyes had nar row angles (grade 0, 1, or 2 of Shaffer classifi cation). Moreover, four patients had acute angle-closure glaucoma. In our study we only examined glaucoma patients and this may ex plain the different prevalence found by us as compared to the research of Gross, Tingey, and Epstein, which also took simple pseudoex foliation, without glaucoma patients, into con sideration. Moreover, they considered only eyes with occludable angles, whereas in our study we also included in the narrow-angle group eyes with Shaffer's grade 2 angles, which are not necessarily occludable. Another interesting finding in our study was a statistically significant difference of narrowangle prevalence between males (17.5%) and females (27.8%).
The clinician, before starting with any medi cal therapy, should be aware that eyes with pseudoexfoliation syndrome have an increased prevalence of occludable angles and should consider the risk of an acute angle-closure glaucoma attack. Such patients should be care fully followed up with gonioscopy as well as tonometry, to decide if and when they must be treated with laser iridotomy. PAOLO BRUSINI, M.D. CLAUDIA TOSONI, M.D. PAOLO MIANI, M.D.
Udine, Italy
Reference 1. Brusini, P., Tosoni, C , and Miani, P.: Glaucoma pseudoesfoliativo ad angolo stretto: un'entita' gu rara? Boll. Ocul. 72(Suppl. 6):141, 1993.
Photorefractive Keratectomy for the Correction of Myopia and Astigmatism EDITOR:
In the article, "Photorefractive keratectomy for the correction of myopia and astigmatism," by J.-P. Colliac, H. J. Shammas, and D. J. Bart (Am. J. Ophthalmol. 117:369, March 1994), there were impressive differences between the reduction of cycloplegic myopic refraction and the reduction in keratometric readings. This discrepancy could only partly be explained by decentration of the ablation. We have been performing excimer laser pho torefractive keratectomy for myopia for 3V2 years and have found much larger discrepan cies than those described by Colliac, Sham mas, and Bart. The differences increased with higher correction (Table). Keratometric values were identical when measured with the Javal keratometer and with the topographic map ping system. The values were similar when looking at the points of highest ablation. No correlation could be found to the degree of decentration. It has been postulated that scar formation in the cornea causes a change in the refractive index. This is theoretically possible, although we would not expect such large discrepancies. Nor could we find any correlation to haze for mation. It is theoretically possible that the kerato metric value in the center of the cornea, since
October, 1994
AMERICAN JOURNAL OF OPHTHALMOLOGY
test, and the American Optical Vectograph using the 20/40 line. The four outcome groups were based on the postoperative motor and sensor functions. These sensory results, al though not specifically mentioned in our re port, were part of the definition of the four outcome groups as described by von Noorden. This article defines the criteria for success as determination of stability of visual acuity, whether further surgery was required and out come group classification status changed. We thank Drs. Arthur and Scott for their queries into the results and the rationale of our group ing. With this particular classification schema, separation of outcome groups 1 and 2 appears to be relevant. YAACOV SHAULY, M.D. THOMAS C. PRAGER, Ph.D. MALCOLM L. MAZOW, M.D.
Houston, Texas
Increased Prevalence of Occludable Angles and Angle-closure Glaucoma in Patients With Pseudoexfoliation EDITOR:
In the article, "Increased prevalence of oc cludable angles and angle-closure glaucoma in patients with pseudoexfoliation," by F. J. Gross, D. Tingey, and D. L. Epstein (Am. J. Ophthalmol. 117:333, March 1994), we sup port the authors' findings. We believe that these findings are important, and more than speculative. In a previous study 1 we described 149 pa tients with pseudoexfoliation glaucoma. We found an even higher prevalence of such cases. Indeed, 21.5% of the examined eyes had nar row angles (grade 0, 1, or 2 of Shaffer classifi cation). Moreover, four patients had acute angle-closure glaucoma. In our study we only examined glaucoma patients and this may ex plain the different prevalence found by us as compared to the research of Gross, Tingey, and Epstein, which also took simple pseudoex foliation, without glaucoma patients, into con sideration. Moreover, they considered only eyes with occludable angles, whereas in our study we also included in the narrow-angle group eyes with Shaffer's grade 2 angles, which are not necessarily occludable. Another interesting finding in our study was a statistically significant difference of narrowangle prevalence between males (17.5%) and females (27.8%).
The clinician, before starting with any medi cal therapy, should be aware that eyes with pseudoexfoliation syndrome have an increased prevalence of occludable angles and should consider the risk of an acute angle-closure glaucoma attack. Such patients should be care fully followed up with gonioscopy as well as tonometry, to decide if and when they must be treated with laser iridotomy. PAOLO BRUSINI, M.D. CLAUDIA TOSONI, M.D. PAOLO MIANI, M.D.
Udine, Italy
Reference 1. Brusini, P., Tosoni, C , and Miani, P.: Glaucoma pseudoesfoliativo ad angolo stretto: un'entita' gu rara? Boll. Ocul. 72(Suppl. 6):141, 1993.
Photorefractive Keratectomy for the Correction of Myopia and Astigmatism EDITOR:
In the article, "Photorefractive keratectomy for the correction of myopia and astigmatism," by J.-P. Colliac, H. J. Shammas, and D. J. Bart (Am. J. Ophthalmol. 117:369, March 1994), there were impressive differences between the reduction of cycloplegic myopic refraction and the reduction in keratometric readings. This discrepancy could only partly be explained by decentration of the ablation. We have been performing excimer laser pho torefractive keratectomy for myopia for 3V2 years and have found much larger discrepan cies than those described by Colliac, Sham mas, and Bart. The differences increased with higher correction (Table). Keratometric values were identical when measured with the Javal keratometer and with the topographic map ping system. The values were similar when looking at the points of highest ablation. No correlation could be found to the degree of decentration. It has been postulated that scar formation in the cornea causes a change in the refractive index. This is theoretically possible, although we would not expect such large discrepancies. Nor could we find any correlation to haze for mation. It is theoretically possible that the kerato metric value in the center of the cornea, since