|Year : 2021 | Volume
| Issue : 2 | Page : 242-243
Posterior stromal crystalline keratopathy in gout
Mohamed Ibrahime Asif, Rahul Kumar Bafna, Kalathil Reshmi Shaji, Mrinalini Anand Yadav, Rajesh Sinha
Department of Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
|Date of Submission||01-Jun-2020|
|Date of Acceptance||03-Sep-2020|
|Date of Web Publication||01-Apr-2021|
Dr. Rajesh Sinha
Cornea, Lens and Refractive Surgery Services, R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
A 55-year-old female presented with painless, diminution of vision in the right eye for 6 months. She had episodes of knee pain in the past. Slit lamp bio-microscopy revealed crystal-like deposits in the deeper corneal stroma in the right eye. Anterior segment optical coherence tomography and confocal microscopy revealed crystalline deposits. Systemic work-up revealed tophi in the right great toe with persistently high serum uric acid over the past ranging from 9 to 12 mg%. The patient is on follow-up and currently on medical therapy for gout. Gout may be associated with crystalline deposits in corneal stroma that may cause blurring of vision.
Keywords: Crystalline keratopathy, gout, hyperuricemia
|How to cite this article:|
Asif MI, Bafna RK, Shaji KR, Yadav MA, Sinha R. Posterior stromal crystalline keratopathy in gout. Indian J Ophthalmol Case Rep 2021;1:242-3
Gout, a common metabolic disorder, occurs due to prolonged hyperuricemia due to hematological, renal, or idiopathic causes. The incidence and prevalence of gout have risen in recent times to approximately 1–4% of the general population. It is the most common type of inflammatory arthritis. It is characterized by deposition of monosodium urate (MSU) crystals called “tophus” in various parts of the body especially peripheral joints presenting with pain. Deposits in ocular adnexa and periocular regions have been described in the literature.,,,,,,, We herein present a case of crystalline deposits in the posterior corneal stroma in a patient of gout.
| Case Report|| |
A 55-year-old female presented with painless, progressive diminution of vision of the right eye noticed for the past 6 months. There was no history of redness in the past. There was no history of trauma or ocular surgery. The patient had history of episodes of knee pain and wrist pain for the past 10 years, which was being managed medically as and when required. She was not on any medication at the time of presentation to us. The best corrected visual acuity was 20/40 OU and intraocular pressure on noncontact tonometry (Nidek NT-530P) was 14 mm of Hg in both the eyes. On slit lamp biomicroscopy, there were fine crystal-like deposits in the mid and deep stroma of the right eye but the left eye was unremarkable [Figure 1]a and [Figure 1]b. Specular reflection revealed normal endothelial morphology. Corneal sensations were normal. Anterior chamber was deep without any sign of inflammation. Posterior segment evaluation revealed healthy disc and macula without any sign of posterior segment inflammation.
|Figure 1: (a) Diffuse illumination showing crystalline deposits on the cornea. (b) Slit illumination showing crystalline deposits on the mid and deep stroma of the cornea. (c) ASOCT showing hyperreflective area involving the mid and deep stroma. (d-f) Confocal imaging showing needle-like crystalline deposits in different sections of mid and posterior corneal stroma|
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On systemic examination, patient had tophi in the right great toe. Blood investigations were normal except a persistently high serum uric acid over the past ranging from 9 to 12 mg%. Anterior segment optical coherence tomography (ASOCT) revealed hyperreflective deposit in the mid and deep stroma [Figure 1]c. Confocal microscopy revealed multiple needle-shaped hyperreflective deposits seen in the mid and posterior stroma of the right eye [Figure 1]d, [Figure 1]e, [Figure 1]f. The epithelium, anterior stroma, and endothelium were normal without any deposit. The left eye of the patient did not reveal any crystalline deposit on confocal microscopy. She was put on carboxymethylcellulose 0.5% eye drops three times a day and was referred to rheumatology for management of gout and was called for follow up after 3 weeks.
| Discussion|| |
Gout is a disorder that is characterized by deposition of MSU crystals in the joints and tendons, usually in the presence of prolonged hyperuricemia. It usually presents as acute monoarthritis followed by periods of remission and exacerbation. Although precipitation of urate crystals in extravascular tissue is a well-established finding, ocular deposition has been infrequently described in the literature. Conjunctival vessel tortuosity, conjunctiva hyperemia, and subconjunctival haemorrhage exacerbated by purine intake are common manifestations of gout that may go unrecognized. Cases of gout presenting with band-shaped keratopathy (BSK), cataract, glaucoma, optic neuritis, and vascular thrombosis have been described. Tophi are the pathognomonic hallmark of gout. Tophi deposits have been described in the eyelids and canthus,, conjunctiva, cornea,, anterior chamber and iris, sclera, and orbit. A case of peripheral ulcerative keratitis along with crystalline deposits in the stroma secondary to hyperuricemia has also been described. Another patient with BSK and scintillating crystals scattered in Bowman membrane without any thinning has been reported.
The pathogenesis of crystalline deposits in the eye is poorly understood. Uric acid remains dissolved in the plasma; however, in corneal stroma, it tends to crystalize as ocular structures do not act as an effective solvent as plasma and especially with lower tissue temperature in the corneal stroma; the chances of crystalline deposit of MSU become high. In a patient of hyperuricemia with orbital mass, rhomboidal shaped crystals with yellow to brown birefringence on polarized light have been described. The subconjunctival deposits reported were cuboidal shaped crystals and were found in clusters. In some instances in gout, urates appear as amorphous structures in the tissues with no definite crystalline formation. In articles showing MSU deposits in cornea, there is no definite description of the morphology of the deposits. In one case, there were multiple chalk-like deposits in the superficial stroma with no definite morphology. In another case series of 380 patients of gout, two patients had deposits in cornea: The first patient had three irregular crystals in the superficial stroma of the cornea, separated from the other transparent cornea by a clear high density ring-like zone. The second patient had cluster of irregular flake-like deposit in the epithelium and superficial stroma. Crystalline deposits in the mid and deep corneal stroma along with needle-shaped crystalline morphology in confocal microscopy have not been described in literature.
The patient was referred to the Department of Rheumatology for management of hyperuricemia. There are no reports in the literature to whether the crystalline deposits in the cornea or ocular adnexa disappear after successful hypouricemic treatment. However, there are studies showing reduction of serum uric acid to normal levels resulting in disappearance of crystals from the synovial fluid. This is dependent on the duration of the gout as longer period is required in those patients with gout of longer duration. We would like to follow up the patient for a long period to see whether a good control of uric acid level can result in reduction of the deposited crystals in corneal stroma.
| Conclusion|| |
Hyperuricemia in active cases of gout can result in crystalline deposits in corneal stroma causing blurring of vision. The morphology and extent of these crystals can be very well delineated by confocal microscopy and ASOCT.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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