|Year : 2012 | Volume
| Issue : 2 | Page : 115-117
Kearns-Sayre syndrome: An unusual ophthalmic presentation
Syed S Ahmad, Shuaibah A Ghani
Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, 88586, Malaysia
|Date of Web Publication||4-Aug-2012|
Syed S Ahmad
Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, 88586
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Kearns-Sayre syndrome (KSS) belongs to the group of neuromuscular disorders known as mitochondrial encephalomyopathies. It has characteristic syndromal features, which include: chronic progressive external ophthalmoplegia, bilateral atypical pigmentary retinopathy, and cardiac conduction abnormalities. So far, only a single case has been reported where a patient with KSS had a normal retina. Herein, we report this extremely rare variant of KSS, which not only presented later than the normal age of presentation, but also had minimal pigmentary retinopathy.
Keywords: Atypical pigmentary retinopathy, Kearns-Sayre syndrome, ptosis, red ragged fibers
|How to cite this article:|
Ahmad SS, Ghani SA. Kearns-Sayre syndrome: An unusual ophthalmic presentation. Oman J Ophthalmol 2012;5:115-7
| Introduction|| |
Kearns Sayre Syndrome (KSS) belongs to the group of neuromuscular disorders known as mitochondrial encephalomyopathies. It has characteristic syndromal features which include: Chronic progressive external ophthalmoplegia (CPEO), bilateral atypical pigmentary retinopathy and cardiac conduction abnormalities. So far, only a single case has been reported where a patient with KSS had a normal retina. Herein, we report this extremely rare variant of KSS, which not only presented later than the normal age of presentation, but also had minimal pigmentary retinopathy.
| Case Report|| |
A 61-year-old female of Chinese descent first reported in the eye clinic of our hospital almost 10 years back. She had complained of progressively increasing ptosis and limitation of ocular movements in both eyes. During those visits, her retinal examination had shown a few depigmented spots near the superior arcade in the right eye and a single spot in the inferior periphery in the left eye. Over the years the patient had come for regular follow up and the spots were consistently noted by different examiners.
However, on a recent review in our clinic, she was found to have the following findings: her best corrected visual acuities were 20/40(OD) and 20/70(OS). She had severe bilateral ptosis and extraocular movements were severely restricted in all directions of gaze [Figure 1]. Both direct and consensual pupillary reactions were briskly present. Examination of anterior segments showed nuclear sclerosis in both eyes. However, the fundus examination was remarkable in its findings. The right eye showed a hypopigmented patch with central hyperpigmentation below the inferior arcade [Figure 2]. The left eye had no significant retinal findings [Figure 3]. The hypopigmented spots, which had been noted previously, were not seen at this time.
The patient underwent a cardiac assessment, which revealed a first-degree atrioventricular block. Her blood sugar was elevated and an endocrine referral was made. She was subsequently started on oral hypoglycemic agents by the endocrinologist. The patient had difficulty in hearing and an otorhinology consultation has been done. A neurologic consultation was also done to rule out any other neurologic conditions like myasthenia gravis. Apart from the raised blood sugar the hematological workup did not reveal any other abnormality. Antiacetylcholine antibodies were also negative. A muscle biopsy of the orbicularis muscle was performed. Modified Gomori trichrome staining revealed the presence of ragged red fibers in the muscle specimen. These findings confirmed the diagnosis of KSS in this patient.
|Figure 1: Appearance of the patient. The arrows denote the tapes used to elevate the lids|
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| Discussion|| |
KSS is a disorder caused by mitochondrial dysfunction. The first human disease attributed to mitochondrial dysfunction was Luft disease. It is a hypermetabolic state in a patient with normal thyroid function and abnormally large mitochondria in skeletal muscles. The abnormal mitochondria seen in these disorders were discovered to stain with Gomori trichrome stain and observed under the light microscope as ragged red fibers (RRFs). KSS has been attributed to point mutations and large-scale deletions in mitochondrial deoxyribonucleic acid (mtDNA). Recently, some of the functional abnormalities in mtDNA have been attributed to anomalies in nuclear deoxyribonucleic acid (nDNA). 
KSS is invariably identified by the triad of: (i) onset before 20 years of age, (ii) progressive external ophthalmoplegia, and (iii) pigmentary retinopathy. In addition, there must be one of the following: heart block (often requiring a pacemaker), cerebellar syndrome, or cerebrospinal fluid protein content of 100 mg/dl or more. KSS may also manifest with: mental retardation, limb weakness, high-frequency sensorineural hearing loss, seizures, short stature, delayed puberty, and cerebral spongiform degeneration.  Endocrine disorders found to be associated with KSS include: diabetes mellitus, growth hormone deficiency, hypoparathyroidism, and other endocrinopathies. 
The association of ophthalmoplegia and pigmentary degeneration was first described by Bernard and Scholz in 1944.  In 1946, Paul Sandifer reported the association of ophthalmoplegia and cardiomyopathy. The cerebral spongiform state found in this syndrome was later described by Daroff. Hence it is also known as Kearns-Sayre-Daroff syndrome. In 1958, Kearns and Sayre were the first to report two cases having the triad of retinitis pigmentosa, external ophthalmoplegia, and complete heart block. 
The pigmentation seen in KSS is described as atypical with a salt-and-pepper or moth-eaten appearance. It is characterized by a diffuse depigmentation of the retinal pigment epithelium with the greatest effect at the macula. A literature search revealed only a single case of KSS where the retina was normal in appearance.  In another case report, coarse hyperpigmentation of the posterior pole and diffuse hyperpigmentation with irregular depigmentation in the periphery were the only retinal findings noted.  Diffuse chorioretinal degeneration and numerous punctuate whitish spots in both fundi are also known to occur.  In yet another case, the salt-and-pepper retinopathy in a patient of KSS progressed to peripapillary loss of the retinal pigment epithelium and choriocapillaris.  Our patient had unusual retinal lesions in the right eye. Such isolated pigmentary changes have never been reported in the literature. Her left eye showed no retinal abnormalities. Thus, these are unique features in a confirmed case of KSS.
Finally, our patient appears to be a unique variant in the presentation of KSS. The two features which stand out in our patient are: First, she started to develop symptoms of KSS at around 50 years of age, which is an unusually late presentation of this condition. There has only been a single other case reported with a late onset at 44 years of age.  Second, her retinas show no changes seen in typical cases of KSS. This case report proves that KSS can have unusual presentations also.
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[Figure 1], [Figure 2], [Figure 3]