On the ocular findings in ochronosis: a systematic review of literature

Pseudofilariasis, a Presenting Sign of Alkaptonuria

PURPOSE

To report the association of Pseudofilariasis as a presenting sign of Alkaptonuria.

METHOD

Case Report.

RESULTS

A 49-year-old Indian man was referred because of wormlike objects in his left conjunctiva. Ocular and family history was non-contributory. He had not been to India in 15 years. Past medical history revealed hypertension, hypercholesterolemia, arthritis, and a myocardial infarct. He had undergone two stents, bilateral Achilles tendon repairs and bilateral knee replacements. ROS showed longstanding back stiffness and pain. On ocular examination the vision was 20/25 in each eye and positive findings were in the left eye bulbar conjunctival which showed stationary black vermiform (filarial in appearance) foreign bodies along with 2 small corneal limbal pigmented deposits. Conjunctival biopsy showed dilated lymph channels with interstitial proteinaceous material of a light brown color consistent with Ochronotic pigment; hence diagnostic of Alkaptonuria.

CONCLUSIONS

Pseudofilariasis may be a presenting sign of Alkaptonuria and occur years before a clinical diagnosis is made. Filariasis is always involves white worms and never black. Knowing the ophthalmic signs of this rare disease may lead to an accurate diagnosis earlier thusly avoiding unnecessary tests and examinations.

Exogenous Ochronosis With Ocular Involvement From Chronic Use of Teavigo

Exogenous ochronosis refers to accumulation of homogentisic acid metabolites in tissues, manifesting as pigmentation of affected tissues. Phenolic compounds are most commonly implicated, including hydroquinone, quinine, phenol, resorcinol, mercury, and picric acid. The affected connective tissues exhibit brownish discoloration when heavily pigmented and the histopathological appearance is characteristic with "banana-shaped" ochre-colored pigment deposits. Herein, the authors describe a rare case of exogenous ochronosis involving the conjunctiva, sclera and skin, as a result of chronic use of Teavigo (94% epigallocatechin gallate), a polyphenol compound with postulated antioxidant and antiapoptotic activity.

Sclerouveitis as Part of Multiple Autoimmune Syndrome in a Patient with Alkaptonuria: A Case Report

PURPOSE

To present a novel association of multiple autoimmune syndrome (MAS) in a patient with sclerouveitis and alkaptonuria.

CASE REPORT

A 68-year-old female with alkaptonuria, Hashimoto's thyroiditis, and familial autoimmunity presented with decreased VA, red eye, foreign body sensation, and ocular pain. Ophthalmological examination: OD conjunctival hyperemia, ochronosis, a reddish-violet scleral nodule, keratic precipitates, 2+ cells in the anterior chamber, 0.5+ vitreous cells, and mild vitreous haze. The patient was diagnosed with anterior uveitis and anterior nodular scleritis. Due to the associated sicca symptoms, a salivary gland biopsy was ordered, confirming Sjögren's syndrome. Then, MAS was diagnosed, and immunomodulatory medications were started; however, as she was refractory to more than two of them, it was suggested to start biological treatment.

CONCLUSION

We present a novel MAS-type 2 pattern consisting of Hashimoto's thyroiditis, sclerouveitis, and Sjögren's syndrome. Its diagnosis and management represent a challenge, so a multidisciplinary approach should be provided.

Descemet's membrane folds in ochronosis: a case report

Background

We present this report of a new ophthalmic finding in a patient with ochronosis.

Case presentation

An 85-year-old Caucasian male patient with bilateral dark temporal and nasal pigmentation of conjunctiva and sclera was referred to our hospital owing to low visual acuity. On biomicroscopic examination, bilateral horizontal Descemet’s membrane folds were observed. Corneal tomography revealed irregular and asymmetric “against-the-rule” astigmatism in both eyes. Anterior segment optical coherence tomography demonstrated numerous central Descemet’s without edema or other corneal structure alterations.

Conclusion

This is the first report of Descemet’s membrane folds in ochronosis. These corneal findings suggest that the accumulation of homogentisic acid in the sclera leads to thickening and stiffness of this region. These alterations could remarkably decrease visual acuity owing to topographic corneal curvature alterations, especially in elderly patients.

Association of alkaptonuria and low dose nitisinone therapy with cataract formation in a large cohort of patients

Homogentisic acid (HGA) lowering, disease modifying off‐label nitisinone therapy has been used in the United Kingdom National Alkaptonuria Centre (NAC) since 2012. This study evaluated the serendipitous observation of cataract in a large cohort of patients with the very rare disease alkaptonuria (AKU), over a 5‐year period. Patients with AKU who attended the NAC since 2012. Standard physical examination and ocular assessment, including photographs of the crystalline lens were taken before commencement of nitisinone 2 mg daily and annually over 5 years. Photographs were randomised and graded by two independent observers using the WHO cataract classification. AKU patients who did not receive nitisinone were included as a control group. HGA was measured on acidified 24 h urine (u‐HGA₂₄) and HGA and tyrosine in fasting acidified serum samples (sHGA, sTYR) at each visit. Patients without suitable lens images were excluded. Cataract (mean grade 1) was noted at baseline in 47 out of 62 (76%) with a mean (SD) age of 44 (14) years. In nitisinone‐treated patients, there were significant increases in the mean grade of nuclear (0.18, p < 0.01) and cortical (0.38, p < 0.01) lens opacities over the mean duration of 4.93 years of the study. Worsening of the nuclear cataract and cortical lens opacities by at least 1 grade was noted in 14 out of 46 (30%) and 11 out of 46 (24%) patients, respectively. There is an increased prevalence and progression of cataract in AKU and a possible association of nitisinone with cataract progression.

Glaucoma With Alkaptonuria as a Result of Pigment Accumulation

PURPOSE

To report a case of alkaptonuria (AKU) in a patient with bilateral conjunctival and scleral black colorization who was diagnosed with glaucoma thereafter.

METHODS

This is a single case report.

RESULTS

A 67-year-old male patient with bilateral black colorization of conjunctiva and sclera was referred to our hospital. In the biomicroscopic examination, globular dark pigmentation was observed in the conjunctiva, sclera, and limbal cornea. The patient was diagnosed with a nuclear cataract in both eyes. He also had gray skin pigmentation at his nose and paranasal area. Corneal topography examination revealed irregular astigmatism. Intraocular pressure values were 29 and 31 mm Hg, in the right and left eye, respectively, with Goldmann applanation tonometry. The diagnosis of AKU was made after pathologic assessment of conjunctival biopsy by the internal medicine department.

CONCLUSIONS

AKU is characterized by the accumulation of homogentisic acid in the connective tissues of many organs including the eye. Patients should be carefully examined in ophthalmology clinics in order to not miss systemic diagnoses. It should be kept in mind that AKU may cause iridocorneal angle pigmentation, which leads to glaucoma, and patients should be treated with proper medication when presenting with elevated intraocular pressure values.

Ochronotic pigmentation is caused by homogentisic acid and is the key event in alkaptonuria leading to the destructive consequences of the disease-A review

Ochronosis is the process in alkaptonuria (AKU) that causes all the debilitating morbidity. The process involves selective deposition of homogentisic acid (HGA)-derived pigment in tissues altering the properties of these tissues, leading to their failure. Some tissues like cartilage are more easily affected by ochronosis while others such as the liver and brain are unaffected for reasons that are still not understood. In vitro and mouse models of ochronosis have confirmed the dose relationships between HGA and ochronosis and also their modulation by p-hydroxyphenylpyruvate dioxygenase inhibition. Ochronosis cannot be fully reversed and is a key factor in influencing treatment decisions. Earlier detection of ochronosis preferably by noninvasive means is desirable. A cause-effect relationship between HGA and ochronosis is discussed. The similarity in AKU and familial hypercholesterolaemia is explored and lessons learnt. More research is needed to more fully understand the crucial nature of ochronosis.

Ochronotic Arthropathy: Two Case Reports from a Developing Country

Alkaptonuria is a rare inborn error of metabolism, which is classified as an orphan disease. It is due to the lack of an enzyme homogentisate 1,2-dioxygenase, which results in an accumulation of homogentisic acid in different areas of the body, including sclera, skin, cardiac valves, articular cartilage of the large joints and intervertebral disks. We present two cases of alkaptonuria resulting in ochronotic arthropathy with advanced secondary generalized osteoarthritis, intervertebral disk calcifications, skin and scleral pigmentation. In these case reports, both patients had symptoms for >10 years before being diagnosed. Conservative management in the form of high-dose ascorbic acid, exercises, and gait aids was offered to both of them, which resulted in some symptomatic improvement in the first case, while the second case was lost to follow-up. Alkaptonuria is a rare disease, and although it does not clearly impact mortality, early diagnosis may improve the quality of life.