Thesis Viva Guide: Universal Neonatal Eye Screening

Your thesis in one sentence

1. Opening presentation: 1 to 2 minute answer

“My thesis evaluated universal neonatal eye screening at a tertiary care centre in the Bundelkhand region. The rationale was that several congenital and neonatal ocular conditions are not apparent on routine examination but may cause permanent visual impairment if detected late.

This hospital-based cross-sectional observational study included 1,100 live-born neonates examined within 48 hours of birth between October 2024 and December 2025. After informed parental consent, all neonates underwent external ocular examination, red reflex testing, and indirect ophthalmoscopy. Maternal and neonatal risk factors were also recorded.

Ocular anomalies were identified in 86 neonates, giving a prevalence of 7.82%. The most common ocular finding was subconjunctival haemorrhage, seen in 48 neonates or 4.36%. Low birth weight and prematurity showed strong statistically significant associations with ocular abnormalities, while sex was not significantly associated.

The study concludes that universal neonatal eye screening is feasible and helps identify both benign birth-related findings and potentially vision-threatening congenital ocular anomalies at an early stage, allowing timely referral and intervention.”

2. Aim and objectives

Aim

Written aim

Better viva wording

“The aim was to perform universal ocular screening of all eligible newborns within 48 hours of birth at a tertiary care centre, in order to detect ocular abnormalities early.”

Why screen within 48 hours?

“The first 48 hours are a practical postnatal window because the baby is still admitted, examination can be coordinated with neonatal care, early referral can be arranged before discharge, and congenital or birth-related abnormalities can be detected promptly.”

Primary objective

Written primary objective

Viva explanation

“The primary objective was to determine the presence of ocular abnormalities through universal screening of newborns within 48 hours of birth.”

Secondary objective

Written secondary objective

Better scientific wording for viva

“The secondary objective was to estimate the prevalence and spectrum of ocular abnormalities detected during universal neonatal eye screening, and to assess their association with neonatal and maternal risk factors.”

Important viva correction

“That wording should ideally be prevalence rather than incidence. Since this was a cross-sectional study and each neonate was assessed at one point in time, the study estimates the prevalence of ocular abnormalities at birth, not incidence over a period of follow-up.”

3. Rationale and need for the study

Why was this study needed?

“Newborns can have anterior segment, posterior segment, and congenital ocular abnormalities that may not be detected through routine general neonatal examination alone. Conditions such as congenital cataract, congenital glaucoma, corneal opacity, persistent fetal vasculature, coloboma, retinal pathology, and leukocoria-related disorders require early detection because delayed treatment may lead to irreversible visual loss, amblyopia, or, in certain conditions, delayed diagnosis of life-threatening disease such as retinoblastoma.”

Why universal rather than selective screening?

“Selective screening examines only high-risk neonates, such as preterm or low-birth-weight babies. However, some important congenital eye abnormalities can occur in term neonates with no recognized risk factors. Universal screening therefore has the advantage of detecting both high-risk and apparently normal newborns with ocular abnormalities.”

Why was the Bundelkhand region important?

“There was limited local epidemiological data on the burden and pattern of neonatal ocular abnormalities in the Bundelkhand region. This study provides local data that can support planning of screening and referral services.”

4. Materials and methods: complete viva explanation

Study design

Answer

“This was a hospital-based cross-sectional observational study.”

Why cross-sectional?

“Each newborn was examined during a defined early postnatal period, within 48 hours of birth. The study measured the presence of ocular abnormalities and recorded associated risk factors at that time. Therefore, it was cross-sectional.”

Why observational?

“There was no intervention, randomization, or allocation of treatment. We only examined and recorded clinical findings and risk factors.”

Why hospital-based?

“The study was carried out among neonates delivered at Government Medical College, Datia, including maternity wards and NICU. Therefore, it represents a hospital-delivered newborn population rather than the entire community population.”

Study setting

“The study was conducted in the maternity wards and NICU of the Departments of Obstetrics and Gynaecology and Paediatrics, in collaboration with the Department of Ophthalmology, Government Medical College, Datia, Madhya Pradesh.”

Study duration

“The study duration was 18 months. Data collection was undertaken from October 2024 to December 2025, followed by data analysis and dissertation writing.”

Study population

“The study population consisted of live newborns delivered at Government Medical College, Datia, who underwent ocular examination within 48 hours of birth and whose parents or legal guardians gave written informed consent.”

Sample size

What was the calculated sample size?

“The calculated minimum sample size was 236 newborns.”

Formula

• Z = 1.96 at 95% confidence level
• P = expected prevalence of ocular abnormality = 19% or 0.19
• Q = 1 - P = 0.81
• E = allowable error = 5% or 0.05

Why were 1,100 babies included when the minimum sample size was 236?

“Although the minimum calculated sample size was 236, we screened 1,100 eligible newborns during the study period. A larger sample improves precision of prevalence estimation, increases the number of detected uncommon abnormalities, and improves power for examining associations with risk factors.”

If asked about the expected prevalence of 19%

“The expected prevalence was taken from previous neonatal eye-screening literature available at the protocol stage. The purpose of using it was to calculate the minimum required sample size.”

5. Sampling technique

Written method

Best viva answer

“All eligible neonates delivered during the study period were enrolled consecutively until the desired sample size was achieved. Although the protocol uses the term convenience sampling, the more precise description is consecutive sampling of eligible hospital-born newborns.”

Why is this important?

Limitation of this sampling method

“As this was a single-centre hospital-based study using consecutive non-probability sampling, the findings may not be fully generalizable to all newborns in the community or to other institutions.”

6. Inclusion criteria

Criteria

1. All live newborns delivered at Government Medical College, Datia.
2. Newborns examined within 48 hours of birth.
3. Written informed consent from parents or legal guardians.

Viva answer: why these criteria?

“Live-born neonates were included because the purpose was to screen babies who could undergo a clinical ocular examination. The 48-hour criterion ensured a uniform early screening window. Informed consent was necessary because the study involved clinical examination and data collection from newborns.”

7. Exclusion criteria

Criteria

1. Parents or legal guardians did not provide consent.
2. Critically ill newborns in whom ocular examination was not feasible or was medically contraindicated.

Why were critically ill babies excluded?

“In critically ill neonates, stabilization and life-saving care take priority. Ocular examination may be unsafe, impractical, or medically contraindicated at that time. Such babies should ideally undergo deferred ophthalmic assessment once clinically stable.”

Possible limitation due to this exclusion

“Excluding critically ill babies may lead to underestimation of ocular abnormalities in the sickest neonates, particularly those with prematurity, hypoxia, sepsis, or prolonged oxygen exposure.”

8. Variables

Independent or exposure variables

• Sex
• Birth weight
• Gestational age
• Mode of delivery
• Maternal infections and systemic illness
• Antenatal complications
• Prematurity
• NICU admission
• Oxygen therapy
• Neonatal systemic conditions

Outcome variable

“The main outcome variable was the presence or absence of ocular abnormality. Secondary outcomes included the type and spectrum of ocular abnormality.”

9. Examination procedure

Equipment used

• Torchlight
• Direct ophthalmoscope
• Indirect ophthalmoscope
• Condensing lens
• Sterile paediatric lid speculum
• Structured data collection proforma

Stepwise ocular examination

1. External examination

“External ocular examination included assessment of the eyelids, conjunctiva, sclera, cornea, iris, pupil, ocular size, discharge, swelling, and visible congenital anomalies.”

• Epicanthal folds
• Congenital entropion
• Subconjunctival haemorrhage
• Corneal opacity
• Limbal dermoid
• Microcornea or megalocornea
• Buphthalmos
• Microphthalmos
• Anophthalmos

2. White reflex examination

“White reflex examination was performed to detect leukocoria, which may indicate cataract, retinoblastoma, persistent fetal vasculature, retinal detachment, or other media and retinal abnormalities.”

Why is leukocoria important?

“Leukocoria is a warning sign. It requires urgent ophthalmic evaluation because causes include congenital cataract and retinoblastoma, both of which may have serious visual or life-threatening consequences.”

3. Red reflex test

“Red reflex testing was performed using direct ophthalmoscopy to identify asymmetry, dimness, absence of reflex, or abnormal colour of the reflex. It helps detect media opacity and posterior segment pathology.”

Conditions red reflex can help detect

• Corneal opacity
• Congenital cataract
• Vitreous abnormalities
• Persistent fetal vasculature
• Retinal detachment
• Retinoblastoma
• Significant refractive asymmetry
• Strabismus, with Bruckner test

Difference between white reflex and red reflex

“White reflex examination detects visible leukocoria, whereas red reflex examination uses an ophthalmoscope to evaluate the quality and symmetry of the pupillary red reflex. An abnormal red reflex may identify subtler media opacity, refractive asymmetry, or posterior segment pathology.”

4. Bruckner test

“The Bruckner test is a binocular red reflex test. It compares the brightness and colour of red reflexes from both eyes. An asymmetry may indicate strabismus, anisometropia, significant refractive error, or media opacity.”

5. Indirect ophthalmoscopy

“Indirect ophthalmoscopy was used for detailed fundus examination, particularly in preterm neonates and NICU babies. It helps detect retinal haemorrhage, retinal immaturity, peripheral retinal abnormalities, and findings requiring ROP surveillance.”

Why indirect ophthalmoscopy?

“It provides a wider field of view than direct ophthalmoscopy and is more useful for peripheral retinal evaluation in neonates.”

10. Outcome measures

Primary outcome

“Prevalence of ocular abnormalities among screened newborns.”

Secondary outcomes

“The spectrum of ocular abnormalities and their association with gestational age, birth weight, mode of delivery, and selected maternal and neonatal risk factors.”

11. Statistical analysis

Software

“Data were entered in Microsoft Excel and analysed using SPSS version 29.”

How variables were presented

“Continuous variables, such as birth weight, were expressed as mean plus or minus standard deviation. Categorical variables were expressed as frequencies and percentages.”

Statistical tests

“Chi-square test was used to assess associations between categorical variables, and a p-value less than 0.05 was considered statistically significant.”

What does p < 0.05 mean?

“It means that, assuming there is truly no association, the probability of observing a difference at least as large as the one found is less than 5%. It suggests statistical evidence of an association, but it does not prove causality.”

What is the chi-square test used for?

“The chi-square test compares observed and expected frequencies in categorical variables. In this study it was used, for example, to assess whether ocular anomalies were associated with low birth weight, gestational age, or sex.”

Can this study prove causation?

“No. A cross-sectional observational study can demonstrate association but cannot establish causality or temporal sequence.”

12. Main results: numbers to memorize

Total sample

• 1,100 newborns

Sex distribution

• Male: 583, 53.0%
• Female: 517, 47.0%

Gestational age

• Preterm: 110, 10.0%
• Term: 942, 85.6%
• Post-term: 48, 4.4%

Mode of delivery

• Normal vaginal delivery: 862, 78.4%
• LSCS: 195, 17.7%
• Ventouse-assisted delivery: 42, 3.8%

Birth weight

• Mean birth weight: 2325.8 ± 716.2 g
• Range: 970 to 4050 g

13. Main ocular findings

Overall ocular anomaly prevalence

• Ocular anomalies: 86 newborns
• Prevalence: 7.82%
• No ocular anomaly: 1,014 newborns, 92.18%

How was 7.82% calculated?

Most common ocular anomaly

• Subconjunctival haemorrhage: 48 cases, 4.36%

Why is subconjunctival haemorrhage common in newborns?

“It is usually a benign birth-related finding caused by transient venous congestion and mechanical pressure during delivery. It generally resolves spontaneously and usually does not affect vision.”

Other important anterior-segment or congenital findings

Fundus findings

Important point

• 86 newborns with ocular anomalies, based on the congenital and external ocular anomaly table.
• Fundus findings include retinal immaturity, retinal haemorrhage and some unvisualized fundi.

14. Associations and statistical results

Birth weight and ocular anomalies

• Chi-square: 206.82
• p-value: <0.001

Viva interpretation

“Ocular anomalies were significantly more common among low-birth-weight neonates. The association was highly statistically significant, with p less than 0.001.”

Approximate proportions

• LBW: 62/165 = 37.6%
• Normal birth weight: 24/935 = 2.6%

“The proportion of anomalies was much higher in low-birth-weight babies than in babies with normal birth weight.”

Gestational age and ocular anomalies

• Chi-square: 93.13
• p-value: <0.001

Viva interpretation

“Gestational age was significantly associated with ocular anomalies. Preterm babies had a greater burden of abnormalities, which is biologically plausible because retinal and ocular development may be incomplete at birth.”

Sex and ocular anomalies

• Chi-square: 0.43
• p-value: 0.51

Interpretation

“Although more male babies had anomalies numerically, there was no statistically significant association between sex and ocular abnormalities. Therefore, sex was not found to be an independent risk factor in this study.”

Paediatric risk factors associated with anomalies

• Low birth weight: p < 0.001
• Low birth weight with respiratory distress syndrome: p < 0.001
• Perinatal asphyxia/HIE: p = 0.01
• Respiratory distress: p = 0.02
• Neonatal convulsions: p = 0.04

Viva explanation

“These conditions may be associated with prematurity, immature retinal vasculature, hypoxia, altered retinal circulation, systemic illness, and impaired neonatal development. However, as this was an observational cross-sectional study, these results demonstrate association and not causation.”

Maternal risk factors associated with anomalies

• Pregnancy-induced hypertension: p = 0.003
• Gestational diabetes mellitus: p = 0.04
• Obstructed labour: p = 0.01
• TORCH/perinatal infection: p = 0.03

Interpretation

“Some maternal conditions were significantly associated with neonatal ocular abnormalities. Possible pathways include fetal growth restriction, altered placental perfusion, prematurity, intrauterine infection, and birth-related stress. These are associations and should not be interpreted as proof of direct causality.”

15. Conclusions: best viva answer

“The study found that ocular abnormalities were present in 7.82% of screened newborns. Most babies had normal ocular findings, but universal screening identified both minor self-limiting conditions and important congenital abnormalities requiring ophthalmic assessment.

The most common ocular finding was subconjunctival haemorrhage. Low birth weight and prematurity were strongly associated with ocular abnormalities, whereas sex was not significantly associated.

Therefore, universal neonatal eye screening within the early postnatal period is feasible in a tertiary care setting and can facilitate early detection, referral, follow-up, and management of potentially vision-threatening disorders.”

16. Recommendations

“Universal neonatal eye screening should be integrated into routine postnatal care, initially at least in tertiary-care delivery centres. Every newborn should undergo external examination and red reflex assessment. High-risk neonates, especially preterm, low-birth-weight, NICU-admitted, and systemically unwell babies, require detailed ophthalmic evaluation and appropriate ROP surveillance. Training of paediatricians, medical officers, and nursing staff in basic eye examination and referral pathways would improve early detection.”

17. Strengths of your study

1. Large sample size: 1,100 newborns, much higher than the calculated minimum of 236.
2. Universal screening approach: included both high-risk and apparently healthy newborns.
3. Early examination: within 48 hours, allowing identification before discharge.
4. Detailed clinical evaluation: external examination, red reflex, Bruckner test, and indirect ophthalmoscopy.
5. Assessment of maternal and neonatal risk factors.
6. Local data: provides evidence from Bundelkhand, where such data were limited.
7. Potential public-health relevance: supports early referral and prevention of avoidable childhood visual impairment.

18. Limitations of your study

“The main limitations were that it was a single-centre hospital-based study, so generalizability to the whole community may be limited. Consecutive non-probability sampling may introduce selection bias. The cross-sectional design establishes association but not causality. Neonates too ill to undergo examination were excluded, which could underestimate the burden in critically ill babies. Also, there was no long-term follow-up to determine whether transient findings resolved or whether visual outcomes improved after referral and treatment.”

“Advanced wide-field digital retinal imaging was not used. Therefore, subtle posterior segment findings may have been missed compared with studies using RetCam or similar imaging.”

19. Very important data clarification for the viva

Issue 1: Total ocular anomalies versus fundus findings

• 86 neonates with ocular anomalies, 7.82%
• Fundus abnormalities such as temporal retinal immaturity and retinal haemorrhage are described separately.

Safe answer

“The 86 figure refers to the ocular anomaly table used for the overall congenital and external ocular anomaly prevalence. Fundus findings were recorded as a separate screening category, and individual newborns could have overlapping findings. In a future version, I would present a clearly defined mutually exclusive patient-level composite outcome and state explicitly whether retinal findings are included in the overall ocular-abnormality prevalence.”

Issue 2: “Incidence” in objective

Safe answer

“For a cross-sectional study, prevalence is the technically correct term. I would revise the secondary objective from incidence to prevalence and spectrum of ocular abnormalities.”

Issue 3: Convenience sampling versus consecutive enrolment

Safe answer

“The protocol described convenience sampling, but the actual operational method was consecutive enrolment of all eligible babies during the study period. Consecutive sampling is the more accurate term.”

Issue 4: Future tense in methods

Safe answer

“The methods section retained protocol-style future tense during drafting. In the final revised dissertation, this should be converted to past tense because the study has been completed.”

20. Common viva questions with model answers

Q1. What was the most important finding of your study?

“The most important finding was that 7.82% of screened neonates had ocular anomalies, and low birth weight and prematurity were strongly associated with these abnormalities. This supports universal neonatal eye screening with special attention to high-risk babies.”

Q2. What was the most common ocular abnormality?

“Subconjunctival haemorrhage was the most common ocular abnormality, seen in 48 newborns or 4.36%.”

Q3. What was the most common posterior segment finding?

“Temporal retinal immaturity was the most common fundus finding at 8%, followed by retinal haemorrhage at 5%.”

Q4. Why is congenital cataract important?

“Congenital cataract can obstruct the visual axis during the critical period of visual development and cause deprivation amblyopia. Early detection, referral, and timely management are essential for visual prognosis.”

Q5. Why is congenital glaucoma important?

“Congenital glaucoma can cause buphthalmos, corneal edema, photophobia, epiphora, raised intraocular pressure, optic nerve damage, and permanent visual loss. It requires urgent specialist evaluation and management.”

Q6. What is persistent fetal vasculature?

“Persistent fetal vasculature, previously called persistent hyperplastic primary vitreous, results from failure of regression of the embryonic hyaloid vascular system. It commonly presents as unilateral leukocoria, microphthalmia, cataract, retrolental fibrovascular tissue, or retinal traction.”

Q7. What is ROP?

“Retinopathy of prematurity is a vasoproliferative retinal disorder of premature and low-birth-weight infants caused by incomplete retinal vascular development and abnormal vascular proliferation. It can progress to retinal detachment and blindness if not detected and treated in time.”

Q8. Does every preterm neonate require ROP screening?

“ROP screening should follow national or institutional eligibility criteria based on gestational age, birth weight, and clinical risk factors. Preterm and low-birth-weight babies require particular attention, especially those with prolonged oxygen exposure, respiratory distress, sepsis, or unstable clinical course.”

Q9. Why is low birth weight associated with ocular abnormalities?

“Low birth weight is frequently associated with prematurity, incomplete retinal vascularisation, systemic illness, hypoxia, respiratory distress, and metabolic instability. These factors can increase vulnerability to retinal and developmental ocular abnormalities.”

Q10. Why can vaginal delivery be associated with retinal or subconjunctival haemorrhage?

“During vaginal delivery, transient increased pressure and mechanical stress during passage through the birth canal can cause venous congestion and rupture of small ocular vessels. Most birth-related haemorrhages are self-limiting, but detailed examination and follow-up are needed when indicated.”

Q11. Why did you include term neonates if ROP is mainly a preterm disease?

“The study was not limited to ROP. It evaluated the full spectrum of neonatal ocular abnormalities, including congenital cataract, glaucoma, corneal opacity, coloboma, leukocoria, retinal haemorrhage, and other abnormalities that may occur in term neonates.”

Q12. What is the significance of a red reflex test?

“The red reflex test is a simple, rapid, non-invasive screening method to detect media opacity, leukocoria, cataract, persistent fetal vasculature, retinal pathology, and significant refractive asymmetry. An abnormal or asymmetric reflex requires urgent ophthalmic referral.”

Q13. Can a normal red reflex rule out all retinal disease?

“No. A normal red reflex is useful but cannot rule out all posterior segment disease, especially peripheral retinal abnormalities. That is why indirect ophthalmoscopy or wide-field imaging is valuable in selected high-risk neonates.”

Q14. Why was sex not significantly associated with ocular abnormalities?

“There was a small numerical predominance of anomalies among male babies, but the difference was statistically non-significant, with p = 0.51. This suggests that sex was not an important risk factor in our study population.”

Q15. What does p < 0.001 mean?

“It indicates very strong statistical evidence against the null hypothesis of no association. It does not mean that the risk factor causes the ocular abnormality, particularly in a cross-sectional study.”

Q16. What would you improve in a future study?

“I would conduct a multicentric prospective study with probability-based sampling, standardized wide-field retinal imaging where feasible, masked image interpretation, a clearly defined composite outcome, and longitudinal follow-up for visual and anatomical outcomes.”

Q17. Can your findings be generalized to the whole population?

“The findings are most directly applicable to newborns delivered at similar tertiary-care hospitals. Because this was a hospital-based, single-centre study using non-probability sampling, extrapolation to the entire community should be cautious.”

Q18. What practical change do you recommend?

“Routine external ocular examination and red reflex testing should be incorporated into newborn care before discharge, with systematic referral pathways for abnormal findings and detailed screening of high-risk neonates.”

21. Final 30-second conclusion for viva

“Universal neonatal eye screening identified ocular abnormalities in 7.82% of newborns in our tertiary-care setting. The commonest finding was subconjunctival haemorrhage, while low birth weight and prematurity had strong associations with ocular abnormalities. Screening within 48 hours of birth is feasible and can help identify congenital and retinal abnormalities early, allowing timely referral and reducing the risk of avoidable childhood visual impairment.”