Assessing characteristics of retinoblastoma on visual acuity: a cohort study

Abstract

Background: Retinoblastoma is a curable eye cancer with high survival rates (>90%) when diagnosed and treated early. Visual prognosis is affected by tumour classification, location, treatment and heredity. While newer treatment modalities enhance globe salvaging and vision preservation, the long-term clinical outcomes of visual acuity (VA) and functional vision are still understudied, leading to challenges for parents in understanding their child's vision. Aim: To investigate the different factors influencing VA outcomes and functional vision in patients diagnosed with retinoblastoma.

Methods: This retrospective observational cohort study included all patients with retinoblastoma from a national centre between 1991-2015. Patients with missing data on treatment modality and inaccurate VA measurements were excluded. VA outcomes were measured at ages 7, 12, and 18 using the LogMAR scale with recognition acuity. Functional vision was assessed using the international PEDIG scale for visual impairment (VI). Effects of tumour classification, location, treatment modalities and heredity on VA outcomes were analysed.

Results: This study included 271 patients with 379 retinoblastoma-diagnosed eyes. At age 7, enucleation rate was 60% (229 eyes), with 18% experiencing VI. Tumour classification, location, treatment, and heredity were strongly associated with VA outcomes (p<0.001). Familial heredity showed the best VA outcomes (LogMAR 0.20), sporadic heredity had severe VI prevalence (31%), and sporadic non-hereditary had high enucleation rates (93%). Foveal tumours resulted in poor VA outcomes (LogMAR 1.80), while peripheral tumours had better outcomes (LogMAR 0.00). Tumour classification, location and treatment are correlated with each other (p<0.001). Therefore influencing VA and leading to increased VI in advanced-staged tumours and more aggressive treatments.

Conclusion: Patients with retinoblastoma exhibited high rates of blindness due to enucleation, but maintained high functional vision without VI (82%). Heredity played a vital role, showing the importance of early screening. Tumour location significantly impacted VA outcomes with localization closer to the macula resulting in poorer vision. Less severe tumours received less aggressive treatments, leading to better VA outcomes. Recommendations: The findings of this study provide valuable insights for personalized support, highlighting the urgent need for a new classification system considering vision preservation and further exploration of vision-related quality of life effects.