Seibeth et al1 describe efficacy and safety using transscleral infrared diode laser peripheral ablation for retinopathy of prematurity (ROP). Conjunctival puncture for the delivery of posterior burns was required in 84% of the eyes. Fortunately, postoperative periorbital morbidity was low; however, such incisions require additional operative time and technique and expose the orbit to more infectious and hemorrhagic risks. I described a technique by which far-posterior ROP cryotherapy can be provided without conjunctival puncture2 If the power and duration of the transcleral laser is relatively constant for a given patient, even when delivered across an extraocular muscle tendon, then a similar limbus-based external reference could be applied to transscleral laser as well.
Robert W. Arnold. Limbus-Based External Reference Coagulation in Transscleral Diode Laser Photocoagulation for Threshold Retinopathy of Prematurity. Arch Ophthalmol. 1998;116(10):1404. doi: