Visual Functions and Retinal Morphology in Patients with Polypoidal Choroidal Vasculopathy

Background and Context

Polypoidal choroidal vasculopathy (PCV) is an exudative maculopathy characterised by abnormal choroidal blood vessels that develop multiple polyp-shaped aneurysmal dilatations. These vascular abnormalities lead to recurrent episodes of serous and haemorrhagic detachment of the retinal pigment epithelium and neurosensory retina, resulting in progressive visual impairment if left untreated. PCV was first described in the 1980s and was initially considered a rare variant of age-related macular degeneration (AMD). However, subsequent research — particularly from Asian populations — has established that PCV is far more common than initially appreciated, accounting for an estimated 22% to 62% of presumed neovascular AMD cases in Asian populations, compared to approximately 10-20% in Caucasian populations.

The high prevalence of PCV in Asian populations makes this condition a significant ophthalmic public health concern in Malaysia, where the ageing population is expanding rapidly. Unlike typical neovascular AMD, PCV has distinct clinical features, prognostic characteristics, and treatment response patterns. The visual prognosis of PCV is generally more favourable than that of typical AMD, with less tendency towards fibrous scarring, but the condition’s chronic and recurrent nature means that affected individuals may require prolonged treatment and monitoring to preserve vision.

Study Design and Population

This was a single-centre, longitudinal, prospective study conducted at a public tertiary hospital in Malaysia (Hospital Selayang) — a designated national referral centre for age-related macular degeneration. Thirty-three treatment-naïve PCV eyes of 32 patients (mean age 67.62 ± 8.05 years) were enrolled. PCV diagnosis was confirmed using indocyanine green angiography (ICGA), the gold standard imaging modality for identifying the characteristic polypoidal lesions. All patients received treatment with intravitreal ranibizumab (an anti-vascular endothelial growth factor agent), with or without adjunctive photodynamic therapy, according to clinical judgement.

Comprehensive visual function assessments were performed at baseline and at six months post-treatment. These included distance visual acuity (DVA) and near visual acuity (NVA) measured in logarithm of the minimum angle of resolution (logMAR), contrast sensitivity (CS), and reading speed (RS). Retinal morphology was assessed using spectral-domain optical coherence tomography (SD-OCT), which provided detailed cross-sectional imaging of the retinal layers, sub-retinal fluid, and pigment epithelial detachments.

Visual Function Outcomes

Treatment resulted in meaningful improvements across all measured visual function parameters. Mean distance visual acuity improved by 0.24 logMAR (approximately two lines on a standard letter chart), while mean near visual acuity improved by 0.30 logMAR. Contrast sensitivity — the ability to distinguish objects from their background under varying conditions of luminance — improved by 0.39 log contrast units, and reading speed increased by an average of 25.58 words per minute. These functional improvements are clinically significant and translate to meaningful benefits in patients’ daily activities, including reading, face recognition, mobility, and driving.

The improvements in visual function correlated with the anatomical improvements observed on OCT. The resolution of sub-retinal fluid and reduction in pigment epithelial detachment height were associated with restored retinal architecture, which in turn supported improved visual processing. This structure-function correlation underscores the importance of timely treatment initiation before irreversible photoreceptor damage occurs.

Retinal Morphology Changes

OCT imaging revealed substantial anatomical improvement following treatment. The proportion of eyes with sub-retinal fluid decreased from 84.35% at baseline to 21.88% at six months — a resolution rate of approximately 74%. Pigment epithelium detachment, which was present in 100% of eyes at baseline, resolved completely or partially in more than half of treated eyes by six months. These morphological changes indicate effective suppression of the exudative activity driven by the abnormal polypoidal choroidal vessels.

PCV in the Malaysian Context

Malaysia’s multi-ethnic population — comprising Malay, Chinese, Indian, and indigenous communities — presents a diverse genetic and environmental background for the study of age-related eye diseases. The prevalence of PCV has been documented across Malaysian ethnic groups, with patterns of clinical presentation and disease morphology described in multiracial cohorts. As Malaysia’s population ages, the burden of PCV and other age-related macular diseases is expected to increase, placing additional demands on ophthalmic services and retinal subspecialty care.

Access to the diagnostic imaging (ICGA) and therapeutic modalities (intravitreal anti-VEGF injections, photodynamic therapy) required for PCV management remains concentrated in tertiary referral centres. Expanding access to these services, training ophthalmologists in PCV diagnosis and management, and developing referral pathways that minimise delays in treatment initiation are important public health priorities for preserving vision in Malaysia’s ageing population.

Limitations

This was a single-centre study with a relatively small sample size and a six-month follow-up period. PCV is a chronic condition with a tendency for recurrence, and longer follow-up studies are needed to assess the durability of treatment outcomes. The absence of a control group limits the ability to attribute visual improvements solely to treatment rather than natural disease fluctuation. Additionally, the study did not assess patient-reported quality of life outcomes, which would provide complementary information about the real-world impact of treatment on daily functioning.

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