Recognition and Prevention of Ocular Morbidity Due to Retinopathy of Prematurity in High Risk Twin Infant Pairs

Aim: This study was performed to determine profile of asymmetry, newer differences in postnatal risk
factors and effects of current laser treatment on retinopathy of prematurity (ROP) progression in
preterm twin pairs.
Methods: A retrospective study was conducted on 250 infants (125 twin pairs) of premature birth, low
weight or other infant risk factors at Sri Ramachandra hospital, a tertiary referral hospital in Chennai,
India from May 2017 to April 2019. Indirect ophthalmoscopy with scleral indentation was performed
on all babies under continuous monitoring of oxygen saturation using pulseoximeter in the presence
of a neonatologist. Examination and analysis was done for stage and zone of ROP, systemic causes,
spontaneous regression and need for treatment.
Results: Among 125 twin pairs, 38twin pairs (30%) had ROP which was asymmetrical in 27% and
symmetrical in 4%. Disparity developed before 35 weeks when both twins had ROP. Two stage
differences occurred in 84%. Both were statistically significant (p<0.05). Spontaneous regression
occurred after 35 weeks and majority regressed by 40 weeks. Laser treatment was required in 36%.
Risk factors were most commonly respiratory distress, patent ductus arteriosus, apnoea, variation of
birth weight and gestational age.
Conclusion: Smaller gestational age is a good predictor of variability in progression of
vascularization and along with birth weight and weight gain contributes to asymmetry. Respiratory
distress has the highest risk. It is important to screen and follow up all twins irrespective of initial
examination status and normal appearing retina in one twin, as transition from one stage to another
can occur. Early detection with timely treatment will prevent irreversible visual loss. This study
highlight the importance of concurrence between the ophthalmologist and neonatologist during
screening, detection and follow up in all twins irrespective of initial examination status and normal
appearing retina in one twin.