Pterygia and retinitis pigmentosa
2
Case Reports Pterygia and retinitis pigmentosa Fraser MacKenzie Lawrence W Hirst Alan Hilton" In October 1988, a 34-year-old white man, from outback Queensland, presented to the Princess Alexandra Hospital, Brisbane, with visual acuity of light perception only in both eyes, and bilateral nasal and temporal pterygia, which had been present since the age of 13 years. The patient was mentally retarded, attributed to an episode of encephalitis as a child, although his eyesight was said to have been very poor since birth. It was difficult to obtain an adequate view of his retina because of the large fleshy pterygia which extended almost to the visual axis (Figures 1, 2). Retinal examination through the residual central cornea disclosed findings consistent with the diagnosis of retinitis pigmentosa, with equatorial pigmentary dispersion, optic atrophy and attentuated arterioles. ERG confirmed this diagnosis. There was no family history of retinitis pigmentosa. Figure 1 Bilateral pterygia on right eye. One month later, both pterygia on the left eye were surgically removed in an attempt to improve the patient's vision. Postoperative treatment consisted of thiotepa drops 1:2000, chloramphenicol 0.5% drops and prednisolone sodium phosphate drops 0.5%, all given every four hours for a period of four weeks. When the patient was reviewed three months later, both nasal and temporal pterygia had regrown to their original size. The patient did report that his vision had been slightly better after the pterygium removal, but this could not be substantiated by any objective tests. Further surgery was discussed, but the patient and his mother elected to return to the outback without further treatment. Discussion We estimate from a study performed on 585 patients with 764 pterygia (406 unilateral, 179 bilateral nasal) treated with postoperative beta irradiation, that of all patients with pterygia, approximately one-third will have bilateral nasal pterygia at some stage.' Temporal pterygium occurs much less frequently than nasal pterygium, which may be explained by the albedo effect described by Coroneo.* For a patient to have four large pterygia as described in this case is extremely unusual, not only in number, but in severity. In this case, the patient's blindness was probably due solely to the retinitis pigmentosa, although the extent of the pterygia could have caused extreme astigmatism and reduction in field. Blindness or greatly reduced vision from pterygia is relatively rare, having been described only on a few occa~ions.~.~ From the Division of Ophthalmology, Department of Surgery, 2nd Floor, Lions Clinical Research Building, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, QId 4102. *209 Stafford Road, Stafford, Qld 4053. Reprints: Professor Lawrence W Hirst. Pterygia and retinitis pigmentosa 145
-
Upload
fraser-mackenzie -
Category
Documents
-
view
220 -
download
3
Transcript of Pterygia and retinitis pigmentosa
Case Reports
Pterygia and retinitis pigmentosa Fraser MacKenzie Lawrence W Hirst Alan Hilton"
In October 1988, a 34-year-old white man, from outback Queensland, presented to the Princess Alexandra Hospital, Brisbane, with visual acuity of light perception only in both eyes, and bilateral nasal and temporal pterygia, which had been present since the age of 13 years. The patient was mentally retarded, attributed to an episode of encephalitis as a child, although his eyesight was said to have been very poor since birth. It was difficult to obtain an adequate view of his retina because of the large fleshy pterygia which extended almost to the visual axis (Figures 1, 2). Retinal examination through the residual central cornea disclosed findings consistent with the diagnosis of retinitis pigmentosa, with equatorial pigmentary dispersion, optic atrophy and attentuated arterioles. ERG confirmed this diagnosis. There was no family history of retinitis pigmentosa.
Figure 1 Bilateral pterygia on right eye.
One month later, both pterygia on the left eye were surgically removed in an attempt to improve the patient's vision. Postoperative treatment consisted of thiotepa drops 1:2000, chloramphenicol 0.5% drops and prednisolone sodium phosphate drops 0.5%, all given every four hours for a period of four weeks. When the patient was reviewed three months later, both nasal and temporal pterygia had regrown to their original size. The patient did report that his vision had been slightly better after the pterygium removal, but this could not be substantiated by any objective tests.
Further surgery was discussed, but the patient and his mother elected to return to the outback without further treatment.
Discussion We estimate from a study performed on 585 patients with 764 pterygia (406 unilateral, 179 bilateral nasal) treated with postoperative beta irradiation, that of all patients with pterygia, approximately one-third will have bilateral nasal pterygia at some stage.' Temporal pterygium occurs much less frequently than nasal pterygium, which may be explained by the albedo effect described by Coroneo.* For a patient to have four large pterygia as described in this case is extremely unusual, not only in number, but in severity. In this case, the patient's blindness was probably due solely to the retinitis pigmentosa, although the extent of the pterygia could have caused extreme astigmatism and reduction in field. Blindness or greatly reduced vision from pterygia is relatively rare, having been described only on a few occa~ions .~ .~
From the Division of Ophthalmology, Department of Surgery, 2nd Floor, Lions Clinical Research Building, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, QId 4102. *209 Stafford Road, Stafford, Qld 4053. Reprints: Professor Lawrence W Hirst.
Pterygia and retinitis pigmentosa 145
Figure 2 Bilateral pterygia on left eye.
As a related pathogenic mechanism for the development of both of these diseases is not evident, it is presumed that they coexisted by chance. However, the association would contradict Saads’ finding? that pterygia do not develop in eyes with poor visual acuity, although it is possible that the
pterygia in this case antedated the retinal disease. The case report illustrates the combination of two
rare ocular pathological processes, i.e., retinitis pigmentosa and four advanced pterygia occurring in the same patient, presumably by chance, and both contributing to severe visual loss.
Acknowledgements Supported in part by the Prevent Blindness Foundation and the Princess Alexandra Hospital.
References 1. MacKenzie FD, Hirst LW, Bain CJ. Recurrence rate and
complications following beta irradiation therapy for pterygium. Ophthalmology 1991;98:1776-80.
2. Coroneo M. Albedo concentration in the anterior eye: a phenomenon that locates some solar diseases. Ophthalmic Surg
3. Fritz MH. Blindness from multiple pterygia in an Alaskan
4. Taylor HR, Hollows FC. Pterygium leading to blindness:
5. Saad RS. Pterygium, pingueculum and visual acuity. Aust
1990;21:60-6.
native. Am J Ophthalmol 1959;39:572.
a case report. Aust J Ophthalmol 1978;6:155-6.
J Ophthaimol 1977;5:52-77.
LASER FOR SALE LASAG MICRORUPTOR I1 ND:YAG LASER SYSTEM
Disruptive and Thermal Modes True Temoo Fundamental Mode
0 Dual He-Ne Rotating or Stationery
Zeiss Slit Lamp with Second Observer
This laser is capable of the following procedures:
Low energy Capsulotomy, Iridotomy
Trans scleral Cyclophotocoagulation Suturelysis
Laser
Aiming System
and Beam Splitter
and Vitreolysis
PRICE $59,000.00 Contact - Designs for Vision
008 22 5307 (02) 550 6966
146 Australian and New Zealand Journal of Ophthalmology 1994; 22(2)
