Recognition and Prevention of Visual Loss Due to Retinopathy of Prematurity in High Risk Twin Infant Pairs: A Case Series with a Multi-specialty Approach

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.