Anxiety (PROMIS); Depression (PROMIS); Peer-interaction (PROMIS); Perceived neurocognitive functioning (PROMIS); Participation and activity (PAY-CY); Trauma (KJTS/PCL-5); Health related quality of life (PEDSQL)

Anxiety (PROMIS); Depression (PROMIS); Distress Thermometer-Parents (DT-P); Trauma (PCL-5)

Verbal fluency will be assessed in all participants using the Semantic condition of the Dutch translation of the subtask Word Production of the Developmental Neuropsychological Assessment (NEPSY-III-NL [age 8-12 years]) or the Word Fluency Test (WFT [13-35 years]), a Dutch translation of the Controlled Oral Word Association Test (COWAT)).

NEPSY-III-NL outcomes will be calculated in norm scores (range 0-20; M=10, SD=2), where outcomes between 8-12 are considered average, <8 below average and >12 above average. Outcomes of the WFT will be calculated in T-Scores (range 20-80; M=50, SD=10), were a T-score between 40 and 60 is considered average, <40 below average, and >60 above average.

Visual Motor Integration will be assessed in sighted participants only, using the Visual-Motor Integration (VMI), Visual Perception (VP) and Motor Coordination (MC) of the Beery-Buktenica Developmental Test of Visual-Motor Integration, 6th Edition, Beery-VMI.

Standard scores (range 48-155; Mean=100, SD=15) will be calculated, as well as T-scores (range 55-145; M=50, SD=10). Standard scores between 85-115 are considered average, <85 below average to borderline, and >115 above average to highly gifted. T-scores between 40 and 60 are considered average, <40 below average, and >60 above average.

Sustained auditory attention will be assessed in all participants using the subtask Score! of the Test of Everyday Attention for Children (TEA-Ch [6-16 years]; Publication date 2004) or the Elevator task of the Test of Everyday Attention (TEA [17-35 years]; Publication date 1994). Regarding the TEA-Ch, norm scores (range 1-19; M=10, SD=2) will be calculated, whereas outcomes between 8-12 are considered average, <8 below average, and >12 above average. The Elevator task of the TEA has 7 subsets, the participants receives one point per correct subset (max=7). An outcome of 7 is considered 'Normal', 6 is considered 'Subclinical Abnormal', and <5 is considered 'Clinical Abnormal'.

The Executive functioning (EF) tasks will be assessed in sighted participants only. The Stroop Color Word Test of the Delis-Kaplan Executive Function System (D-KEFS; Publication date 2007) measures selective visual attention, cognitive flexibility, inhibition and processing speed. The Trail Making Test (TMT) of the D-KEFS (publication data 2007) assesses attention, visual screening and cognitive flexibility. Scale scores will be calculated (range 0-20; M-10, SD=2) and scores between 8-12 are considered average, scores <8 are considered below average, and scores >12 above average.

Anxiety (proxy 5-16 years and self-report 8-35 years) is assessed using a digital Patient Reported Outcomes Measurement Information System (PROMIS), computer adaptive testing (CAT) questionnaire (using the Dutch KLIK portal [in Dutch Kwaliteit van Leven in Kaart/Mapping Quality of Life]). A standard Total Scale score (range 0-100) of 0-59 indicate no anxiety symptoms, between 60-69 subclinical anxiety symptoms, and >70 clinical anxiety symptoms.

Depression (proxy 5-16 years and self-report 8-35 years) is assessed using a digital PROMIS-CAT questionnaire (using the Dutch KLIK portal). A Standard Total Scale score (range 0-100) of 0-59 indicate no depression symptoms, between 60-69 subclinical depression symptoms, and >70 clinical depression symptoms.

Peer interaction (self-report 9-17 years) is assessed using a digital PROMIS-CAT questionnaire (using the Dutch KLIK portal). A Standard Scale score (range 0-100) is calculated and outcomes. A norm score of <29 is considered having poor peer relations, between 29 and 39 suboptimal peer relations, and >39 having no peer relation problems.

Perceived neuropsychological functioning (self-report 8-35 years) is assessed using a digital PROMIS-CAT questionnaire (using the Dutch KLIK portal). The questionnaire consists of 7 questions related to perceived problems regarding attention, focus, memory and reading comprehension. Questions are answered on a 4-point Likert scale (1=never, 2=sometimes, 3=often, 4=most of the time).

Due to absence of standard data, standardized outcomes cannot be calculated. Outcomes of participants will be compared to each other, with a low score indicating good perceived cognitive functioning and a high score indicating declined perceived cognitive functioning

Participation and activity (proxy 0-16 years and self-report 8-35 years) is assessed using the digital questionnaire Participation and Activity Inventory for Children and Youth (PAY-CY, publication date 2019, [using the Dutch KLIK portal]). Due to absence of standard data, outcomes (range 0-100) of participants will be compared to each other, with a high score indicating the absence of or fewer obstacles to activity and participation in daily life and a low score indicates much perceived obstacles. Outcomes relate to 'Activity and participation'. Additionally, 'Sensory functioning' and 'Parental component' is also assessed in the proxy questionnaires.

Post-traumatic stress disorder (PTSD; proxy 3-16 years/ self-report 8-35 years) is assessed using the Dutch translation of the Child and Adolescent Trauma Screener (KJTS, in Dutch: Kind en Jeugd Trauma Screener [3-18 years]) or the PTSD Checklist for the DSM-5 (PCL-5 [18-35 years] using the Dutch KLIK portal)).

Standard outcomes of the KJTS (range 0-60) regards 'Total Score', whereas <15 is considered within normal limits, 15-19 subclinical development of PTSD and >20 clinical development of PTSD. Regarding PCL-5, participants report a traumatic event ('Criteria A'). Standard outcomes are calculated in a 'Total Score' and sub scores corresponding to the DSM-5 criteria: 'Criteria B' (intrusive symptoms), 'Criteria C' (persistent avoidance), 'Criteria D' (negative alterations), and 'Criteria E' (arousal and reactivity). A Total Score (range 0-80) between 0-27 indicates no PTSD symptoms, between 28-32 subclinical PTSD development, and a total score of >33 development of clinical PTSD.

Health Related Quality of Life (HRQoL; proxy 0-16 years and self-report 8-35 years) is assessed using the digital questionnaires Preschool Children's Quality of Life questionnaire (TAPQOL [0-2 years]) or Pediatric Quality of Life Inventory (PedsQL [3-35 years] using the Dutch KLIK portal)). All outcomes (range 0-100) will be compared to Dutch norm reference data (bases on age and gender) and cut off scores differ among age. High scores indicate good functioning. A deviation of 10 points below the national average score of same-sex peers is clinically relevant. Subscales of the TAPQOL relates to 'Stomachache', 'Skin Problems', 'Respiratory Problems', 'Sleeping Problems', 'Apatite', 'Positive mood', 'Anxiety', 'Livelihood' and 'Problem behavior'. Subscales of the PedsQL relate to the domains 'Physical Functioning' , 'Emotional Functioning', 'Social Functioning' and 'School functioning'.

Four questions were asked to all participants:

1. Satisfaction with physical appearance, measured on a scale of 0-10 where 0 indicates completely dissatisfied and 10 indicates very satisfied.
2. Whether the participant has been under anesthesia for conditions other than retinoblastoma and if so, how often. (open end)
3. Whether the participant has been diagnosed with a psychiatric (DSM-5) disorder. (open end)
4. An open end question whether the participant would like to add or mention anything the participant considers worth mentioning.

Parental depression is assessed using a digital PROMIS-CAT questionnaire (using the Dutch KLIK portal). Standard outcomes (range 0-100) between 0-59 indicate no depression symptoms, between 60-69 subclinical depression symptoms, and >70 clinical depression symptoms.

Is assessed using the digital Distress Thermometer for Parents (DT-P) questionnaire (using the Dutch KLIK portal). Total perceived stress is rated on a 10 points scale (0=no distress, 10=maximum distress). Domain scores will be calculated, which relate to: 'Practical Functioning', 'Social Functioning', 'Emotional Functioning', 'Physical Functioning', 'Cognitive Functioning', and 'Child-parent Interaction and Upbringing'. High scores on the subdomains indicate higher levels of distress, low scores indicate low levels of distress. Additionally, four questions addresses amount of perceived support, perceived recognition by others, whether the parent is chronically ill itself, and about experience with the medical staff. whether they received supported care by family or professional help and the need to consult a healthcare professional.

Parental trauma related to retinoblastoma (diagnosis, treatment and/or follow-up) is assessed using the Dutch translation of the digital questionnaire PTSD Checklist for the DSM-5 (PCL-5). Parents complete 20 questions related to their child's illness (i.e. (risk of) retinoblastoma) ('Criteria A'). Standard outcomes are calculated in a 'Total Score' and sub scores corresponding to the DSM-5 criteria: 'Criteria B' (intrusive symptoms), 'Criteria C' (persistent avoidance), 'Criteria D' (negative alterations), and 'Criteria E' (arousal and reactivity). A Total Score (range 0-80) between 0-27 indicates no PTSD symptoms, between 28-32 indicates subclinical PTSD development, and a total score of >33 indicates development of clinical PTSD.