Pathophysiology of ocular manifestations in Wilson’s disease and its management

Abstract

Wilson’s disease (WD) is an inherited disorder affecting copper metabolism. Ocular manifestations, particularly Kayser-Fleischer rings and sunflower cataracts, are key diagnostic indicators. This article provides an overview of the pathophysiology of WD and describes current imaging techniques used for the detection and monitoring of the disease: Slit lamp examination, anterior segment optical coherence tomography, and in vivo confocal microscopy. It also touches on other rare ocular manifestations, which include retinal abnormalities, optic neuropathy, and oculomotor abnormalities, which are an extension of systemic symptoms. With the advent of new imaging techniques, the amount of corneal copper deposition can be quantified. Ocular manifestations are used to assess neurological symptoms and the extent of adherence to treatment. Patients suffering from WD are recommended to undergo comprehensive eye exams regularly. This article is a comprehensive literature review up to 2025 and provides an overview of WD for a multidisciplinary team of healthcare workers.

Key Words: Wilson disease; Ocular manifestation; Kayser-Fleischer ring; Sunflower cataract; Copper metabolism

Core Tip: Autosomal recessive ATP7B gene dysfunction in Wilson’s disease causes sequestered copper in hepatocytes to effect oxidative damage and necrosis, subsequently releasing into systemic circulation and reaching the eyes, brain, and kidneys. Free copper binds reversibly with metallothionein protein in the Descemet’s, causing Kayser-Fleischer rings (and anterior capsule, causing rare non-vision-threatening sunflower cataracts)-serving as clinical severity biomarkers for diagnosis and treatment compliance/responsiveness, especially among symptomatic adults. Gonioscopy, anterior segment optical coherence tomography, and confocal imaging strengthen the ophthalmologist’s diagnostic advantage over slit-lamp alone. Children with a family history of consanguinity need early screening due to subtle biochemical abnormalities and nonspecific neurological, behavioral, renal, and hematological symptoms, but they have a good chelation response and yet the possibility of fulminant complications.

INTRODUCTION

Wilson’s disease (WD), also referred to as hepatolenticular degeneration, is an autosomal recessive genetic disorder of copper metabolism induced by mutations in the ATP7B gene on chromosome 13q. This genetic defect reduces the excretion of biliary copper from hepatocytes, leading to pathological accumulation of copper in various tissues. The systemic dysregulation leads to a heterogeneous spectrum of clinical manifestations, primarily affecting the liver and the brain, which are the main sites of toxic copper deposition[1]. As such, the eye acts as a critical diagnostic window into this systemic pathology, manifesting signs of vital clinical importance.

The ophthalmological manifestations of WD provide a crucial diagnostic clue and are a fundamental aspect of the diagnostic workup[1,2]. Among ocular signs, the Kayser-Fleischer (KF) ring is the most characteristic manifestation, which usually is bilateral, but can be unilateral and hence meticulous slit lamp examination, including gonioscopy, is very important[3].

Sunflower cataract, caused by copper accumulation in the anterior capsule of the lens, represents another classic manifestation of WD[1,2]. In addition to the aforementioned symptoms, WD can be associated with other infrequent and serious manifestations. Optic neuropathy, especially the acute onset type, represents an important and infrequently encountered symptom that results in profound visual loss in the patient[2,4].

This review aims to compile the up-to-date literature regarding the typical and atypical presentations of WD in the eyes in order to assist in developing an integrated point of view for treatment and management. This review covers the pathophysiology, presentation, and diagnostic value of the ophthalmological manifestations, ranging from the pathognomonic KF ring and sunflower cataract to potentially vision-threatening optic neuropathy and underrecognized retinal alterations in WD.

LITERATURE SEARCH METHODOLOGY

A structured literature search was done to look for publications related to the topic, involving the ocular symptoms of WD, the pathophysiology, diagnostic workup, and its implications. The database searched has been PubMed/MEDLINE. The search strategy included combinations of the following keywords and Medical Subject Headings: “Wilson’s disease”, “ocular manifestations”, “eye involvement”, “KF ring”, “sunflower cataract”, “cornea”, “retina”, “optic nerve”, “optical coherence tomography”, “anterior segment OCT”, and “copper metabolism”. Boolean operators (“AND”, “OR”) were used to refine the search. To avoid author-name ambiguity, exclusions such as “NOT Wilson [Author]” were applied when appropriate.

Original research articles, observational studies, case reports and series, and reviews involving both adult and pediatric populations published up to 2025 were considered. Abstracts from conferences and non-peer-reviewed publications were excluded.

In the first stage, the papers were filtered through title and abstract for relevance. The full texts were later evaluated for extracting data pertaining to the findings, imaging, pathophysiology, and changes associated with the treatments. Due to the rarity of the condition known as WD and the heterogeneity of the articles published, the review chose to conduct a narrative synthesis review instead of a meta-analysis review.

PATHOPHYSIOLOGY

WD is an inherited disorder involving copper metabolism. It is caused by mutations in the ATP7B gene. This gene encodes the copper-transporting ATPase enzyme, which is present in the liver cells. The enzyme has two main functions. It attaches copper to apoceruloplasmin, which is necessary for the production of functional ceruloplasmin. The second function is the efflux of copper into bile. When the enzyme is not functioning properly, the liver starts accumulating copper. Once the storage capacity of the liver is reached, the excess copper is released into the bloodstream as non-ceruloplasmin-bound or “free” copper. The free copper is distributed outside the liver. It has a tendency to accumulate in other areas, particularly the brain and the eye[2].

There are two main ways in which copper toxicity occurs. The first is through the binding of copper ions to the proteins. This interferes with the normal functions of the cells. The second is through the production of reactive oxygen species (ROS). ROS are produced by the redox reaction of copper. These ROS cause oxidative stress, which can lead to the damage of lipids, proteins, and DNA.

The anterior segment of the eye is particularly vulnerable to copper accumulation. The eye is bathed in an aqueous humor. The aqueous humor contains circulating “free” copper. Two classic signs of WD are the KF ring and the sunflower cataract. These signs are the result of copper accumulation in the avascular structures of the eye.

The KF ring is the accumulation of granular copper-sulfur complexes in Descemet’s membrane at the peripheral cornea[2,5]. The source of the sulfur is the copper-binding protein metallothionein in the eye tissue. The change in the KF ring during chelation therapy can indicate the response rate of the patient. Sunflower cataract results from copper deposition in the anterior lens capsule. The deposits form a characteristic petaloid pattern resembling a sunflower. Because the deposits lie outside the central visual axis, visual acuity is usually preserved. Like the KF ring, sunflower cataracts may regress after effective decoppering therapy and correlate with systemic copper toxicity[5,6].

The anterior segment signs are generally related to direct copper deposition effects, while the posterior segment and neuro-ophthalmology are related to neurodegeneration and metabolic abnormalities. When there is an imbalance in copper metabolism, oxidative stress increases due to an increase in ROS production, which can lead to retinal neuron and retinal pigment epithelium (RPE) damage[7,8].

Experimental studies indicate that copper metabolism can affect mitochondrial function in the RPE layer of the retina, which provides a rationale for the link between copper overload and retinal damage[7,8]. It has been demonstrated that copper overload can lead to mitochondrial dysfunction, activation of unfolded protein responses, and increased retinal cell death in vertebrate models. Some of the effects are partially protected by ROS scavengers, which indicates the role of oxidative stress in retinal damage by copper[9].

The involvement of the optic nerve in WD is also biologically plausible. The retinal ganglion layer is dependent on mitochondrial function, and oxidative stress that reduces mitochondrial membrane potential makes it vulnerable to damage[10]. Other theories for optic nerve damage include abnormalities in axonal transport and optic nerve microcirculation due to metabolic stress[11].

These pathways underscore the need for the examination of the structures of the retina and optic nerve in patients with WD, as well as the cornea, for the study of the ocular manifestations. However, the association between the changes in the posterior segment and systemic control of copper levels has yet to be clearly explained in WD patients[6,7,11].

The role of altered iron metabolism also needs consideration. Ceruloplasmin has the ferroxidase activity that converts Fe²⁺ into Fe³⁺, which then binds with transferrin. If the synthesis of ceruloplasmin is impaired, as in WD, the control of iron metabolism can be disrupted, leading to increased oxidative damage. However, the improvement in vision following anti-copper treatment points to the primary role of direct copper toxicity[4].

The effect of WD on ocular motor systems also needs consideration. Copper deposition in the basal ganglia and brainstem can interfere with the control of eye movements, including the centers that control vertical and horizontal gaze. Neurodegeneration in the basal ganglia can result in ocular motility disorders that can be identified with the aid of magnetic resonance imaging (MRI)[2].

OCULAR MANIFESTATIONS

Ocular involvement is a well-recognized feature of WD and often provides important diagnostic clues. The spectrum of ocular manifestations ranges from anterior segment findings to retinal and neuro-ophthalmic abnormalities.

KAYSER–FLEISCHER RING

Deposition of copper in the cornea, known as the KF ring, constitutes one of the key diagnostic criteria of WD[5]. The KF ring was first described independently by the German ophthalmologists Bernhard Kayser and Bruno Fleischer in the early twentieth century. It consists of fine, pigmented, granular deposits of copper located in the peripheral cornea, specifically within Descemet’s membrane.

Pathophysiologically, free copper loosely bound to albumin enters the aqueous humor and subsequently deposits in Descemet’s membrane, where it combines with sulfur-containing proteins such as metallothionein, producing the characteristic granular pigmentation. The ring typically appears first superiorly as a corneal arc (Figure 1A), followed by inferior involvement (Figure 1B), and eventually forms a complete circumferential ring (Figure 1C)[12-14]. This pattern may be explained by the vertical convection currents of aqueous humor within the anterior chamber[15]. A complete KF ring indicates an advanced disease.

Figure 1 Kayser-Fleischer ring progression in Wilson’s disease. A: Early Kayser-Fleischer (KF) ring appearing as a superior peripheral corneal arc on slit-lamp examination; B: Inferior corneal involvement due to progressive copper deposition; C: Complete circumferential KF ring at the corneal periphery.

A KF ring can be clinically detected with the help of a slit lamp, although in advanced cases they may be visible to the naked eye. It does not affect vision and is clinically observed as a ring of pigmentation around the limbus on cornea. The colour of the ring varies from golden-green to golden-brown, bronze, and even greenish-yellow. KF rings are normally present in both eyes of an individual, although there are some cases where the ring might develop in just one eye[3,16].

The KF ring disappears in the reverse order of its appearance with decoppering. First and foremost, the KF ring starts disappearing horizontally and later starts disappearing from the lower and upper areas. The KF ring is a handy tool to monitor the effectiveness of the treatment and the extent of the patient’s compliance with the treatment plan[17,18]. If the KF ring starts appearing again and looking even more prominent, it might indicate some gaps in the treatment plan and non-compliance on the part of the patient. However, the regression of the KF ring does not necessarily indicate an improvement in the condition of the liver and brain[19,20].

Although highly suggestive of WD, KF rings are not entirely pathognomonic and may occasionally occur in other conditions associated with impaired biliary copper excretion, including primary biliary cholangitis, neonatal cholestasis, and cirrhosis[21,22].

The reported prevalence of KF rings varies according to clinical phenotype. They are present in approximately 36%-62% of patients with hepatic presentations, 77%-95% of those with neurological manifestations, and 10%-30% of asymptomatic individuals with WD[23,24]. Age-related variations with lower prevalence in children compared with adults are also observed. In a pediatric cohort study by Couchonnal et al[25], KF rings were detected in 38.9% of patients. This included 31% of those with hepatic disease and 94.7% of those with neurological involvement.

Although slit-lamp examination remains the standard diagnostic method, subtle cases may be missed, particularly when copper deposition occurs predominantly in the anterior chamber angle. In such situations, gonioscopy may assist in identifying angle pigmentation.

Several imaging techniques have been introduced to improve the detection and monitoring of corneal copper deposits, including anterior segment optical coherence tomography (AS-OCT), scheimpflug imaging, and in vivo confocal microscopy (IVCM) (Figure 2)[19,26].

Figure 2 Imaging modalities used for detection of Kayser-Fleischer ring in Wilson’s disease. A: Slit-lamp photograph demonstrating complete circumferential Kayser-Fleischer (KF) ring pigmentation at the limbus; B: Scheimpflug imaging showing increased peripheral corneal density corresponding to copper deposition; C: Anterior segment optical coherence tomography (AS-OCT) demonstrating a peripheral hyper-reflective band at the level of Descemet’s membrane consistent with KF ring in right eye; D: AS-OCT image illustrating circumferential hyper-reflective deposition along Descemet’s membrane, corresponding to corneal copper accumulation in left eye. OCT: Optical coherence tomography; ART: Ambrosio’s relational thickness; OS: Oculus sinister; OD: Oculus dexter; IR: Infrared; HS: High speed.

AS-OCT provides high-resolution, non-contact cross-sectional imaging of the cornea and can visualise KF rings as a peripheral hyper-reflective band at the level of Descemet’s membrane, corresponding to the clinically visible ring on slit-lamp examination[27-29]. In small clinical series, AS-OCT has been proposed as a practical adjunct for detecting and quantifying corneal copper deposits, enabling more standardized documentation during longitudinal follow-up compared with descriptive slit-lamp grading alone[27,28]. Quantitative parameters such as circumferential ring extent, arc length, and depth of the hyper-reflective band may be measured using standardized scan protocols, allowing comparison between visits. However, prospective comparative studies suggest that AS-OCT may miss early or subtle rings detectable by higher-resolution modalities, and therefore, negative AS-OCT findings should be interpreted cautiously when clinical suspicion remains high[29-31].

IVCM allows cellular-level evaluation of the peripheral cornea and has characterized KF rings as granular hyper-reflective deposits that increase in density toward Descemet’s membrane. These deposits may partially obscure the peripheral endothelium and are often associated with stromal microstructural changes[30]. Comparative studies indicate that IVCM may be more sensitive in detecting KF than AS-OCT[31]. Nevertheless, IVCM evaluates a relatively small corneal field and requires multi-quadrant scanning, making operator expertise and equipment availability important practical considerations. Despite these limitations, the high sensitivity of IVCM and the possibility of density-based scoring systems support its potential role as an imaging biomarker for monitoring disease progression and treatment response when combined with systemic copper indices[30,31]. A stepwise approach for ophthalmological examination, including slit lamp examination, along with the use of other diagnostic techniques such as AS-OCT and IVCM, may help in the early detection of KF ring in suspected cases of WD (Figure 3).

Figure 3 Diagnostic algorithm for detection and monitoring of Kayser-Fleischer ring. ring in suspected Wilson’s disease. AS-OCT: Anterior segment optical coherence tomography; KF: Kayser-Fleischer; IVCM: In vivo confocal microscopy; WD: Wilson’s disease.

Copper deposition may also affect corneal nerves. Confocal microscopy studies have demonstrated alterations in the sub-basal nerve plexus, along with changes in epithelial cell morphology, suggesting the presence of small-fibre peripheral neuropathy in patients with WD[32].

SUNFLOWER CATARACT

Another classical ocular manifestation of WD is the sunflower cataract. Its prevalence varies widely from approximately 2% to 20%[33-37]. Siemerling and Oloff[33] in 1922 described it as a central golden-green opacity beneath the anterior lens capsule, surrounded by radial petaloid extensions resembling the petals of a sunflower.

These opacities result from copper deposition in the anterior lens capsule. Copper interacts with sulfur-containing proteins in the lens capsule, resulting in a characteristic pattern. Because the deposits are located outside the vision, characteristic acuity is usually preserved. Sunflower cataracts are typically detected only on slit-lamp examination and, similar to KF rings, may regress partially or completely following effective decoppering therapy[36].

Sunflower cataracts may also occur in cases of chalcosis bulbi resulting from intraocular copper foreign bodies[34,35]. Langwińska-Wośko et al[37] in their series reported sunflower cataract in 1.2% of newly diagnosed WD patients, which completely resolved after one year of treatment, indicating that it is a reversible manifestation of copper toxicity.

RETINAL AND NEURO-OPHTHALMIC INVOLVEMENT

Recent studies have shown that WD may also involve retina and optic nerve. Spectral-domain OCT (SD-OCT) has demonstrated reduced retinal nerve fibre layer (RNFL) thickness and decreased central macular thickness in patients with MRI evidence of neurological involvement. In contrast, patients with normal MRI have RNFL and macular thickness values comparable to healthy controls[38].

Functional tests like visual evoked potentials and electroretinography have also demonstrated prolonged latencies in patients with neurological disease, suggesting involvement of visual pathways[39,40]. These tests may therefore serve as potential indicators of neurological involvement, although a clear correlation between these parameters and disease progression has not yet been established.

Ocular motility abnormalities have also been associated with WD, including slowed horizontal and vertical saccades, impaired smooth pursuit movements, increased antisaccadic latency, and abnormalities of vertical optokinetic nystagmus[41,42]. Electro-oculographic abnormalities have been seen even in patients without structural brain lesions on MRI[43]. These disturbances are thought to result from copper-induced degeneration within the brainstem and basal ganglia.

OTHER REPORTED OCULAR MANIFESTATIONS

Several less common ocular manifestations of WD have been described in isolated case reports. Optic neuropathy with optic disc pallor has been reported in a few patients in whom no alternative cause was identified. In some cases, visual acuity improved after initiation of anti-copper therapy, suggesting a possible reversible toxic mechanism[44-47].

Additionally, isolated reports of secondary glaucoma[48] and keratoconus[49,50] have also been reported. Gonioscopy in 18 years old patient with WD presenting with raised intraocular pressure revealed yellow-green material covering the trabecular meshwork, and histopathological examination of trabecular tissue demonstrated copper deposition[48]. However, keratoconus was diagnosed concurrently with KF rings at presentation in otherwise asymptomatic patients. Though there is no direct evidence to support a causal association, these occurrences are considered coincidental[49,50].

DIAGNOSTIC EVALUATIONS

The diagnostic evaluation of this disease has evolved from simple observations of corneal rings to a sophisticated multi-pronged approach involving molecular genetics, advanced proteomic biomarkers, and quantitative neuroimaging. The clinical necessity for an exhaustive diagnostic workup is underscored by the fact that WD is one of the few metabolic disorders that is highly treatable with chelating agents (penicillamine or trientine), zinc supplementation to reduce copper absorption, and, in severe cases, liver transplantation. However, it can be fatal if the diagnosis is delayed.

It is diagnosed using a variety of tests, mainly biochemical markers (high 24-hour urinary copper excretion > 100 microgram/24 hours, low ceruloplasmin levels below 5 mg/dL, and relative exchangeable copper > 14.4% are highly suggestive of the diagnosis), a liver biopsy to measure copper (with levels > 250 μg/g dry weight being diagnostic), a slit lamp evaluation for KF ring or sunflower cataracts, and genetic testing for the ATP7B gene mutations (biallelic pathogenic or likely pathogenic) variants[51-53]. Since bile represents the only significant physiological route for copper excretion in humans, mutations that impair the function of the ATP7B protein lead to the progressive sequestration of copper within the hepatocyte cytoplasm[54]. The excess copper initiates oxidative damage, mitochondrial dysfunction, and eventual hepatocyte necrosis and releases large quantities of non-ceruloplasmin-bound copper, or free copper, into the systemic circulation, which subsequently deposits in the central nervous system, particularly the basal ganglia, putamen, and globus pallidus, and other extrahepatic sites such as the cornea and kidneys[51].

MRI abnormalities are found in nearly 100% of neurologically symptomatic patients and approximately 40%-50% of those with purely hepatic presentations. Brain MRI is used to detect copper accumulation in the basal ganglia and putamen (‘face of the giant panda’ sign on an MRI), and a scoring system (Leipzig score of 4 or higher) is used to confirm diagnosis and direct early treatment[55-57].

WD is a disorder of copper metabolism, which, if left untreated, can cause hepatic, neurological, or psychiatric issues, or a combination of these, in people between the ages of three and seventy[56]. Liver disease can include recurrent jaundice, hepatitis, hepatic failure, or chronic liver disease. The alkaline phosphatase to total bilirubin ratio (less than 4) can serve as a highly sensitive indicator during acute liver failure, helping to distinguish this disorder from other forms of sudden hepatitis. Neurologic presentations can include dysarthria, movement disorders, dystonia (mask-like facies, rigidity, gait disturbance, pseudobulbar involvement), seizures, or sleep disorders. Psychiatric manifestations include depression, bipolar disorder, neurosis, or psychosis[58,59].

PEDIATRIC WD

WD in children often presents differently from adults and may be overlooked in the early stages. Pediatric patients commonly develop subtle and nonspecific symptoms such as asymptomatic hepatomegaly, persistent elevation of liver enzymes, behavioural changes, decline in school performance, or mild movement abnormalities[58,60]. As a result, diagnosis is frequently delayed unless a high index of suspicion is maintained. Family screening and incidental detection during evaluation of abnormal liver function tests account for a significant proportion of paediatric diagnoses[60]. The age of presentation in childhood generally ranges between 8 and 11 years, although onset has been reported from early infancy to adolescence[2,61,62]. Hepatic involvement is the most frequent initial manifestation and may vary from mild biochemical abnormalities to chronic liver disease, cirrhosis, portal hypertension, or fulminant hepatic failure[2,61]. Children who present with extrahepatic manifestations at diagnosis usually have advanced liver disease. Among diagnostic investigations, elevated 24-hour urinary copper excretion remains the most sensitive biochemical marker in children, followed by reduced serum ceruloplasmin levels[63], KF rings are relatively uncommon in paediatric patients, and their absence does not exclude the diagnosis of WD[64,65]. Therefore, ocular findings alone should not be used to rule out WD in children. Children may occasionally present with atypical manifestations such as movement disorders, dystonia, tremors, or seizures. Skeletal abnormalities, including pathological fractures and metabolic bone disease, have also been reported. Kidney manifestations in the form of distal renal tubular acidosis and hematologic manifestations in the form of Coombs-negative hemolytic anaemia can be seen in some patients. Consanguineous marriages are a major risk factor for the disease in children, and they should be screened early[2]. From an ocular standpoint, even if the KF rings are not apparent, the ocular examination should not be neglected. AS-OCT is a helpful non-invasive technique for the early detection of corneal copper deposition in children who may not cooperate with the ocular examination[64]. Early diagnosis is essential, as pediatric patients generally show good clinical response to chelation therapy or zinc monotherapy when treatment is initiated promptly.

DIFFERENTIAL DIAGNOSIS

Although ocular findings are highly suggestive of WD, similar corneal changes may be seen in several non-Wilsonian conditions. KF-like rings have been reported in autoimmune chronic active hepatitis and chronic cholestatic liver disease[63]. Peripheral corneal pigmentation may also occur in systemic disorders associated with altered copper metabolism and in patients with malignancies associated with hypercupremia. Intraocular copper-containing foreign bodies may also produce corneal pigmentation resembling KF rings and must be excluded clinically. Pseudo-KF rings refer to peripheral corneal discolouration that mimics true KF rings but is not caused by copper deposition. These alterations may occur as a result of the accumulation of iron or bilirubin in the cornea, particularly in chronic hemolytic disease or biliary obstruction. In primary biliary cholangitis, the pigment is more likely to be found in the deeper layers of the stroma rather than Descemet’s membrane, which helps to distinguish it from a KF ring. Other ocular findings require a careful reading as well. Sunflower cataracts must be distinguished from cataracts due to chalcosis. Nystagmus and ocular motility abnormalities may occur secondary to hepatic encephalopathy, neonatal hepatitis, or prolonged cholestasis and should not be attributed to WD without appropriate systemic correlation[63].

CLINICAL IMPLICATIONS

WD is a multisystem disorder characterized by highly variable involvement of the liver, brain, eyes, kidneys, bones, and psychiatric system. Because many of its manifestations are potentially reversible with timely treatment, early diagnosis remains the most critical determinant of long-term outcome[66]. Ophthalmological examination plays a pivotal role not only in the diagnosis but also in the longitudinal monitoring of the disease. The presence of KF ring may be the first observable clinical sign that raises suspicion of WD, particularly in children presenting with unexplained liver disease, neurological or psychiatric symptoms, or Coombs-negative hemolytic anaemia[66].

Although slit-lamp biomicroscopy remains the gold standard for detecting KF rings, newer imaging modalities such as AS-OCT and IVCM have enhanced the sensitivity of detection and allow objective documentation of copper deposition within the cornea[32,64]. These imaging modalities are particularly useful in early or subtle cases. Moreover, they permit quantitative assessment of corneal deposits, enabling serial monitoring during therapy.

Regression of KF rings following chelation therapy is frequently observed and may serve as a visible indicator of adherence to therapy. However, improvement in ocular signs does not always parallel neurological or hepatic recovery. The disease process can be unpredictable in children, and rapid deterioration can occur if therapy is delayed. Hence, early diagnosis and prompt therapy are necessary. The current recommendations for the management of WD include the screening of children over the age of two years with persistent elevation of liver enzymes[62].

Anti-copper therapy in WD is lifelong, and structured monitoring is essential because interruption of treatment may allow copper re-accumulation and lead to clinical deterioration[6,67-71]. Discontinuation of decoppering therapy has been associated with relapse or worsening of disease manifestations in clinical studies, underscoring adherence as a critical determinant of long-term outcomes[6,70,72]. Because KF rings represent corneal copper deposition and have been shown to regress or disappear during sustained therapy in longitudinal cohort studies, renewed prominence or reappearance of a previously regressing ring should raise suspicion of inadequate decoppering, including treatment non-compliance or interruptions in medication access[70-73].

Therefore, documentation of the ocular trajectory, whether persistence, regression, or recurrence of corneal deposits alongside biochemical indices of copper metabolism, provides a practical and visible indicator for assessing treatment adherence and disease control[6,73-76].

Clinical practice guidelines emphasise the importance of multidisciplinary and longitudinal follow-up in patients with WD, and ophthalmologic evaluation should be incorporated into routine monitoring rather than being limited to an initial diagnostic slit-lamp examination[6,72,73]. At a minimum, baseline and follow-up assessments should document the presence and extent of KF rings as well as evaluate the lens for sunflower cataract formation. Ancillary imaging modalities may be particularly useful when slit-lamp findings are subtle or when objective quantification of corneal deposits is required for longitudinal comparison[27,31,74,76].

When anti-copper therapy is initiated or modified, repeating ophthalmologic evaluation at intervals of approximately 3-6 months may help confirm early regression of corneal deposits and detect persistent or worsening findings suggestive of inadequate decoppering. In clinically stable patients with well-controlled disease, annual ophthalmologic review is generally sufficient, although earlier evaluation may be warranted if symptoms change or if adherence concerns arise. It should be noted that WD-specific evidence defining optimal ophthalmologic follow-up intervals remains limited, and current recommendations are largely extrapolated from systemic monitoring strategies[6,74,75].

Ophthalmic examination should include assessment of visual acuity, intraocular pressure measurement and posterior segment evaluation, particularly when neuro-ophthalmic symptoms are present[7,10,11].

KF rings may also complement biochemical monitoring as a readily visible marker of therapeutic response. Regression or disappearance of the ring during sustained therapy has been documented in longitudinal studies[74,75]. Quantitative corneal imaging further supports this clinical observation by enabling serial measurements, such as AS-OCT assessment of ring extent and IVCM analysis of deposit density, which can be compared across visits to objectively evaluate treatment response[27,28,30,31].

In clinical practice, a mismatch between ocular imaging findings and systemic copper indices should prompt an investigation into treatment adherence, including assessment of medication dosing, tolerability, availability, and financial accessibility. Such an approach may be particularly valuable in early or hepatic-predominant disease presentations, where evidence suggests that IVCM may detect subtle KF rings that might have been missed by AS-OCT or slit-lamp examination[31] (Table 1).

Table 1 Diagnostic performance and clinical utility of anterior segment imaging modalities for detecting Kayser-Fleischer rings in Wilson disease.

Modality	Diagnostic sensitivity1	Diagnostic specificity1	Advantages	Limitations
Slit lamp biomicroscopy	High in clinically evident Kayser–Fleischer rings; reduced in early/subclinical cases	High when characteristic peripheral corneal pigmentation is present	First-line clinical tool; widely available; real-time examination; cost-effective	Operator dependent; limited detection of subtle peripheral deposition; subjective assessment
Anterior segment optical coherence tomography	Moderate-high for hyperreflective deposits at Descemet’s membrane	High	Non-contact; objective structural documentation; reproducible imaging; useful for monitoring regression	Limited cellular resolution; peripheral artifacts; lack of standardized diagnostic cut-offs
In vivo confocal microscopy	High for hyperreflective granular deposits at Descemet’s level	High	Cellular-level imaging; detects microstructural changes; useful in equivocal cases	Contact technique; small field of view; limited availability; not routinely used for screening
Scheimpflug imaging	Moderate (based on corneal densitometry changes)	Moderate-high	Objective densitometry; three-dimensional anterior segment analysis; non-contact	Lower sensitivity for early deposits; limited cellular detail; peripheral ring may be underestimated

¹Sensitivity and specificity estimates are derived from individual observational studies; pooled quantitative meta-analytic estimates are limited due to heterogeneity in study design, imaging protocols, and reference standards.

Ophthalmologists play a critical role in the treatment of WD, since ocular manifestations can precede other signs, giving a window of opportunity for diagnosis and treatment, which can make a huge difference in the outcome of the disease and the extent of any organ damage[66].

FUTURE DIRECTIONS

WD manifests with diverse systemic and ocular manifestations. Although substantial progress has been made in picking up these manifestations, several areas necessitate further investigation to enhance diagnosis, management, and patient outcomes. High-resolution OCT and corneal confocal microscopy provide more comprehensive insights into the structural alterations associated with copper deposition at an early stage[2,67,69]. Further research on molecular pathways by which copper accumulation results in various ocular manifestations, including KF rings and sunflower cataracts, is the need of the hour[69].

In a study comparing imaging modalities, differences in detection sensitivity between AS-OCT and IVCM were found, whereby IVCM detected KF rings not detected by AS-OCT. By establishing a link between corneal imaging biomarkers, including extent, pattern, and density of deposits detected by AS-OCT or IVCM, and systemic disease markers, it may be possible to determine the value of ocular findings as surrogate markers of disease activity[6,31,74]. Future studies may focus on standardised imaging endpoints to improve the reproducibility of results[31]. Systematic reporting of incomplete data, inter-grader variability, and methodological limitations will improve the reliability of future imaging studies in WD.

Incorporating artificial intelligence in image analysis may improve the effectiveness of corneal copper level monitoring in WD. Image analysis may improve the objectivity of image analysis in AS-OCT, reducing operator-dependent variables in image analysis[32]. Deep learning has been successfully applied in image analysis in other eye diseases, including the analysis of AS-OCT and slit-lamp images for lesion detection in other eye diseases, indicating the potential of deep learning in image analysis in WD[77,78].

Early initiation of therapy and adherence to decoppering therapy are essential for optimal outcomes. Discontinuation of therapy may result in worsening of the disease, and initiation of therapy at the earliest in those who are asymptomatic may prevent the development of symptoms[6,70-73]. Longitudinal studies showed that KF rings may improve or resolve with continued therapy, suggesting that early therapy may improve eye-related outcomes, thus making eye manifestations a better marker of therapy response.

Genotype-directed therapy is a novel goal in WD. The variability of mutations of the ATP7B gene is associated with the variability of clinical presentation and imaging abnormalities, particularly in ethnic groups such as those of Indian descent[2]. Experimental studies suggest that epigenetic factors, such as DNA methylation and histone modification, may influence the expression of WD[79-81]. The combination of phenotyping of WD with genomic and epigenetic studies may guide a more personalised approach to patient monitoring.

Finally, the accessibility and cost of advanced imaging techniques are a concern. Anterior segment OCT and IVCM are not accessible to all populations[30,31]. The availability of a more accessible OCT device or a low-cost advanced imaging technique is a potential option for the future[82-84]. A pragmatic approach to follow-up of KF rings may include initial slit lamp or smartphone imaging of the KF rings[85], followed by AS-OCT if the signs are equivocal or require objective quantification of the KF rings, and IVCM if there is a need to rule out other causes of corneal pathology or if the diagnosis is questionable[68,72].

LIMITATIONS OF EXISTING EVIDENCE

There are limited epidemiological studies that accurately describe the prevalence and incidence of ocular manifestations in WD. Because of this, the true burden of ocular involvement remains unclear. Many published studies include small sample sizes or case reports, which reduces their statistical strength and limits wider applicability. Long-term follow-up studies are limited. As a result, the natural course and long-term visual outcomes of ocular changes are not well understood. Interdisciplinary research involving ophthalmologists, neurologists, gastroenterologists, and geneticists to improve understanding of ocular involvement in WD is the need of the hour.

CONCLUSION

The challenges associated with the diagnosis and treatment of WD are many, given the vast differences in the manifestations of the disease. The significance of the role of ocular examination in the diagnosis of WD cannot be overstated. Although the advancement in diagnostic tools using imaging techniques shows a lot of promise, the impact of the disease on the eyes cannot be fully understood without the outcome of well-designed epidemiological studies. It’s necessary to improve the outcome of the disease to improve the quality of life for children suffering from WD across the globe.