EYE GROWTH IN THE APHAKIC NEWBORN RABBIT

Purpose: To examine eye growth in unilaterally lensectomized newborn r abbits. Setting: S:t Erik Eye Hospital, Karolinska Institute, Stockhol m, Sweden. Methods: Unilateral lensectomy was performed in 18 randomly selected 23-day-old rabbits. Corneal incision was performed in 2 othe r rabbits, and the aqueous humor was replaced with balanced salt solut ion in one eye. Axial length, corneal diameter, corneal thickness, int raocular pressure (IOP), and refraction were measured in all eyes preo peratively and 1, 2, and 3 months postoperatively. The wet mass of the after-cataract was measured 3 months after surgery. Results: The grow th of the aphakic eye, as indicated by axial length and corneal diamet er, was significantly less than that of the control eye in 14 rabbits. No significant difference in IOP or corneal thickness was found betwe en the lensectomy and control eyes. Four animals had elevated IOP with secondary glaucoma and were excluded from the study. No difference in eye growth was found between the two eyes when no lensectomy was perf ormed. Refraction in the unoperated eye showed a myopic shift. After l ensectomy, the operated eye became hyperopic with a myopic shift 3 mon ths after surgery. No correlation was found between eye growth and the wet mass of the after-cataract. Conclusions: Our results suggest that removal of the rabbit crystalline lens at an early age reduces eye gr owth.