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Superotemporal Coloboma of the Iris, Ciliary Body, and Choroid
506
October, 1988
AMERICAN JOURNAL OF OPHTHALMOLOGY
Superotemporal Coloboma of the Iris, Ciliary Body, and Choroid Michael C. Brodsky, M . D . , Edward G. Buckley, M . D . , John C. Crittenden, M . D . , and Ruth H. Schirmer Duke University Medical Center. Inquiries to Edward G. Buckley, Μ.Ό., Duke University Eye Center, Box 3802, Durham, NC 27710. A healthy 8-month-old girl was referred for evaluation of microphthalmos of the right eye. She was the full-term product of a normal pregnancy, labor, and delivery, and had weighed 6 lb. 8 oz. at birth. During our examination she was able to fol low an optokinetic target using either eye. The right eye was microphthalmic with a horizontal corneal diameter of 8 mm. A full-thickness, superotemporal iris defect extended from the 10 to 12 o'clock meridian, producing a keyholeshaped pupil (Figure, top). A small strand of iris bridged the colobomatous gap peripherally and a thin pupillary membrane extended across the pupillary border. The lens equator was flattened and irregular behind the iris defect. A contiguous area of bare sclera extended to the superotemporal equatorial retina (Figure, bot tom). Refractive error was -0.50 +5.00 x 147. The optic disk, macula, and peripheral retina were normal. The left eye was normal. Com puted tomography of the head showed no intracranial abnormalities. Atypical iris colobomas are congenital iris defects not located along the inferonasal line of closure of the embryonic fissure. 1 In his review of ocular colobomas, Pagon 2 stated that since atypical iris colobomas do not represent defects in embryonic fissure closure, they are not as sociated with chorioretinal or optic disk col obomas. Atypical choroidal colobomas may originate from localized developmental neuroectodermal defects or from postinflammatory scarring. 3 We believe ours is a singu lar case of atypical coloboma with contiguous iris, ciliary body, and retinochoroidal defects, and no evidence of pigment proliferation or clumping to suggest old inflammation. Klein3 performed histologie examination of one isolat ed, atypical choroidal coloboma and found ir regular folding and lack of normal differentia tion of the outer layer of neuroectoderm, formation of cysts, absence of choroid, thin ning of sclera, and extensive failure of retinal coaptation. In the absence of histologie verifi-
Figure (Brodsky and associates). Top, Right eye demonstrating full-thickness, superotemporal iris defect, producing a keyhole-shaped pupil. A small strand of iris bridges the colobomatous gap adjacent to the corneoscleral limbus, and a thin strand of tissue extends across the pupillary border. Bottom, Posterior aspect of superotemporal retinochoroidal coloboma near equator of right eye. Note absence of pigment clumping or proliferation at the margin of the coloboma. cation, we suspect a similar focal malformation of neuroectoderm, unrelated to intrauterine inflammation.
References 1. Mann, I.: Developmental Abnormalities of the Eye, 2nd ed. Philadelphia, J. B. Lippincott, 1957, pp. 74-93.
Correspondence
Vol. 106, No. 4
2. Pagon, R. A.: Ocular coloboma. Surv. Ophthalmol. 25:223, 1981. 3. Klein, B. A.: The pathogenesis of some atypical colobomas of the choroid. Am. J. Ophthalmol. 48:597, 1959.
Correspondence Correspondence concerning recent articles or other mate rial published in THE JOURNAL should be submitted within six weeks of publication. Correspondence must be typed double-spaced, on 8V2 x 11-inch bond paper with l'A-inch margins on all four sides and should be no more than two typewritten pages in length. Every effort will be made to resolve controversies between the correspondents and the authors of the article before publication.
The Effect of Suture Removal on Postkeratoplasty Astigmatism EDITOR:
In the article, "The effect of suture removal on postkeratoplasty astigmatism," by P. S. Binder (Am. J. Ophthalmol. 105:637, June 1988), the location of the steepest meridian determined by qualitative analysis of the keratoscope photograph shown in Figure 2 is in correct. We analyzed the photokeratograph shown in the figure using the computerassisted method of photokeratograph analysis developed at our institution and determined that the axis of the steepest meridian is locat ed at 40 degrees. This is much closer to the meridian of the upper suture (approximately 45 degrees) than the meridian between the two sutures (approximately 10 degrees), which was said to be the steepest meridian. This error by an esteemed and capable oph thalmologist points out one of the dangers of making decisions in corneal surgery based on qualitative analysis of photokeratographs. Since the upper suture is the major determi nant of the corneal cylinder present, removal of both sutures would probably not yield the expected results. Corneal topographic analysis is still in its infancy. However, the need for accurate methods of analyzing corneal shape is well illustrated by examples such as this one in an otherwise excellent article by Dr. Binder. STEVEN A. DINGELDEIN, M.D. STEPHEN D. KLYCE, Ph.D.
New Orleans, Louisiana
507
Reply EDITOR:
When I use a keratograph to help me de cide which sutures to remove, I have not found it useful to use the comparator or to digitize the photographs because of the time required. I try to compare the keratometry astigmatism axis with what I visually deter mine to be the offending tight suture or su tures. In Figure 2 the two tight sutures marked by the large arrowheads were com pressing the corneal wound creating a steep ening in the axis between the two sutures. Drs. Dingeldein and Klyce have quantitatively determined that the axis of the steep meridian in the photograph that they analyzed from the article was closer to the superior arrow head and not in between the two sutures. Using qualitative keratograph observations with this suture removal technique, it is not clinically significant whether the steep meridi an was at axis 40, 30, or 20 degrees. What matters is that the patient did have two su tures that were producing a steepening vector and therefore both had to be removed. On visual inspection of Figure 2, the upper su ture appeared to be the major determinant of the corneal cylinder that was present. I have been using the corneascope for the last eight years and have been surprised to find that the removal of a given suture by using my tech nique does not always provide the expected result. In this particular example, after the removal of the two sutures, the corneal topog raphy resumed a more spherical configuration in the area of suture removal. PERRY S. BINDER, M.D.
La Jolla, California
Clinical Findings and Common Symptoms in Retinitis Pigmentosa EDITOR:
In the article "Clinical findings and com mon symptoms in retinitis pigmentosa" by J. R. Heckenlively, S. L. Yoser, L. H. Friedman, and J. J. Oversier (Am. J. Ophthal mol. 105:504, May 1988), the authors stated that "many patients were told that their reti nitis pigmentosa either came from their moth er or that it was a genetic disease and that they should not have children." In their dis cussion they then state, "clearly, a number received misinformation from their ophthal-
October, 1988
AMERICAN JOURNAL OF OPHTHALMOLOGY
Superotemporal Coloboma of the Iris, Ciliary Body, and Choroid Michael C. Brodsky, M . D . , Edward G. Buckley, M . D . , John C. Crittenden, M . D . , and Ruth H. Schirmer Duke University Medical Center. Inquiries to Edward G. Buckley, Μ.Ό., Duke University Eye Center, Box 3802, Durham, NC 27710. A healthy 8-month-old girl was referred for evaluation of microphthalmos of the right eye. She was the full-term product of a normal pregnancy, labor, and delivery, and had weighed 6 lb. 8 oz. at birth. During our examination she was able to fol low an optokinetic target using either eye. The right eye was microphthalmic with a horizontal corneal diameter of 8 mm. A full-thickness, superotemporal iris defect extended from the 10 to 12 o'clock meridian, producing a keyholeshaped pupil (Figure, top). A small strand of iris bridged the colobomatous gap peripherally and a thin pupillary membrane extended across the pupillary border. The lens equator was flattened and irregular behind the iris defect. A contiguous area of bare sclera extended to the superotemporal equatorial retina (Figure, bot tom). Refractive error was -0.50 +5.00 x 147. The optic disk, macula, and peripheral retina were normal. The left eye was normal. Com puted tomography of the head showed no intracranial abnormalities. Atypical iris colobomas are congenital iris defects not located along the inferonasal line of closure of the embryonic fissure. 1 In his review of ocular colobomas, Pagon 2 stated that since atypical iris colobomas do not represent defects in embryonic fissure closure, they are not as sociated with chorioretinal or optic disk col obomas. Atypical choroidal colobomas may originate from localized developmental neuroectodermal defects or from postinflammatory scarring. 3 We believe ours is a singu lar case of atypical coloboma with contiguous iris, ciliary body, and retinochoroidal defects, and no evidence of pigment proliferation or clumping to suggest old inflammation. Klein3 performed histologie examination of one isolat ed, atypical choroidal coloboma and found ir regular folding and lack of normal differentia tion of the outer layer of neuroectoderm, formation of cysts, absence of choroid, thin ning of sclera, and extensive failure of retinal coaptation. In the absence of histologie verifi-
Figure (Brodsky and associates). Top, Right eye demonstrating full-thickness, superotemporal iris defect, producing a keyhole-shaped pupil. A small strand of iris bridges the colobomatous gap adjacent to the corneoscleral limbus, and a thin strand of tissue extends across the pupillary border. Bottom, Posterior aspect of superotemporal retinochoroidal coloboma near equator of right eye. Note absence of pigment clumping or proliferation at the margin of the coloboma. cation, we suspect a similar focal malformation of neuroectoderm, unrelated to intrauterine inflammation.
References 1. Mann, I.: Developmental Abnormalities of the Eye, 2nd ed. Philadelphia, J. B. Lippincott, 1957, pp. 74-93.
Correspondence
Vol. 106, No. 4
2. Pagon, R. A.: Ocular coloboma. Surv. Ophthalmol. 25:223, 1981. 3. Klein, B. A.: The pathogenesis of some atypical colobomas of the choroid. Am. J. Ophthalmol. 48:597, 1959.
Correspondence Correspondence concerning recent articles or other mate rial published in THE JOURNAL should be submitted within six weeks of publication. Correspondence must be typed double-spaced, on 8V2 x 11-inch bond paper with l'A-inch margins on all four sides and should be no more than two typewritten pages in length. Every effort will be made to resolve controversies between the correspondents and the authors of the article before publication.
The Effect of Suture Removal on Postkeratoplasty Astigmatism EDITOR:
In the article, "The effect of suture removal on postkeratoplasty astigmatism," by P. S. Binder (Am. J. Ophthalmol. 105:637, June 1988), the location of the steepest meridian determined by qualitative analysis of the keratoscope photograph shown in Figure 2 is in correct. We analyzed the photokeratograph shown in the figure using the computerassisted method of photokeratograph analysis developed at our institution and determined that the axis of the steepest meridian is locat ed at 40 degrees. This is much closer to the meridian of the upper suture (approximately 45 degrees) than the meridian between the two sutures (approximately 10 degrees), which was said to be the steepest meridian. This error by an esteemed and capable oph thalmologist points out one of the dangers of making decisions in corneal surgery based on qualitative analysis of photokeratographs. Since the upper suture is the major determi nant of the corneal cylinder present, removal of both sutures would probably not yield the expected results. Corneal topographic analysis is still in its infancy. However, the need for accurate methods of analyzing corneal shape is well illustrated by examples such as this one in an otherwise excellent article by Dr. Binder. STEVEN A. DINGELDEIN, M.D. STEPHEN D. KLYCE, Ph.D.
New Orleans, Louisiana
507
Reply EDITOR:
When I use a keratograph to help me de cide which sutures to remove, I have not found it useful to use the comparator or to digitize the photographs because of the time required. I try to compare the keratometry astigmatism axis with what I visually deter mine to be the offending tight suture or su tures. In Figure 2 the two tight sutures marked by the large arrowheads were com pressing the corneal wound creating a steep ening in the axis between the two sutures. Drs. Dingeldein and Klyce have quantitatively determined that the axis of the steep meridian in the photograph that they analyzed from the article was closer to the superior arrow head and not in between the two sutures. Using qualitative keratograph observations with this suture removal technique, it is not clinically significant whether the steep meridi an was at axis 40, 30, or 20 degrees. What matters is that the patient did have two su tures that were producing a steepening vector and therefore both had to be removed. On visual inspection of Figure 2, the upper su ture appeared to be the major determinant of the corneal cylinder that was present. I have been using the corneascope for the last eight years and have been surprised to find that the removal of a given suture by using my tech nique does not always provide the expected result. In this particular example, after the removal of the two sutures, the corneal topog raphy resumed a more spherical configuration in the area of suture removal. PERRY S. BINDER, M.D.
La Jolla, California
Clinical Findings and Common Symptoms in Retinitis Pigmentosa EDITOR:
In the article "Clinical findings and com mon symptoms in retinitis pigmentosa" by J. R. Heckenlively, S. L. Yoser, L. H. Friedman, and J. J. Oversier (Am. J. Ophthal mol. 105:504, May 1988), the authors stated that "many patients were told that their reti nitis pigmentosa either came from their moth er or that it was a genetic disease and that they should not have children." In their dis cussion they then state, "clearly, a number received misinformation from their ophthal-