YS YU, et al. LENS-SPARING VITRECTOMY FOR ROP Table 1. Surgical outcome of lens-sparing vitrectomized eyes for stage 4 and stage 5 retinopathy of prematurity Case No. ROP stage Len-sparing vitrectomized eyes Post-op retina Last follow-up vision Post-op complications 1 4a+ A L 2 4a++ A F 3 4a++ A F 4 4a++ D - 5 4b+ D - retinal break* 6 4b+ A F cataract 7 4b+ D - vitreous hemorrhage 8 4b+ A L 9 4b+ A L 10 4b+ A F 11 4b+ D - vitreous hemorrhage 12 4b+ A F 13 4b++ A F 14 5+ A - cataract 15 5+ D - vitreous hemorrhage, cataract 16 5+ D - glaucoma 17 5+ D - glaucoma +: moderate degree of plus disease, ++: severe degree of plus disease, 4a: subtotal retinal detachment without macular involvement, 4b: subtotal retinal detachment with macular involvement, A: attached retina, D: detached retina, F: form vision, L: light follow, -: no light perception, *: intra-operative complication. Table 2. Overall success rate of lens-sparing vitrectomy for stage 4 and stage 5 retinopathy of prematurity Stages of ROP 4a 4b 5 Success rate 3/4 (75.0%) 6/9 (66.7%) 1/4 (25.0%) Total 10/17 (58.8%) ROP: retinopathy of prematurity, 4a: subtotal retinal detachment without macular involvement, 4b: subtotal retinal detachment with macular involvement, success: attached retina in the posterior pole. better than those with stage 5 ROP (Table 2). Discussion Lens-sparing vitrectomy in infants has been used to treat tractional retinal detachment and vitreous hemorrhage associated with ROP, non-clearing preretinal hemorrhage secondary to shaken-baby syndrome, and posterior persistent fetal vasculature.23-26,30-33 Although this procedure tends to be more difficult in infants than in adults or children because of their relatively large lens size compared to the posterior segment of their eye, it can cautiously be done without damage to the lens. The crystalline lens in infants can be spared by employing a two-port pars plicata approach, and also by inserting instruments parallel to the visual axis.35 After lens-sparing vitrectomy in infants, 67% of the lenses remained clear after an average follow-up time of 27 months.25 Our results showed that three cases of cataract formation had occurred after an average follow-up time of 2.2 years, and that 82.4% of the lenses remained clear after surgery. Only two of these required further surgery. Recently, Hartnett23 reported that a poor surgical outcome after surgery for stages 4 and 5 ROP was related to the presence of vitreous organization, neovascularization, and plus disease. Surgical procedures included scleral buckling, lensectomy-vitrectomy, and lens-sparing vitrectomy, but similar outcomes resulted from scleral buckling and lens- sparing vitrectomy in those with stage 4b ROP. Capone and Trese26 reported that 90 percent of the eyes with stage 4a ROP exhibited successful retinal reattachment after lens- sparing vitrectomy. Our results also showed a success rate of 75% and 66% for stages 4a and 4b each. The success rate plummeted to 25% for stage 5 patients. In the present study, lens-sparing vitrectomy produced better results in cases of stage 4 ROP than in patients with stage 5. Hartnett23 found that the surgical outcome was not associated with the type of surgery chosen for stage 4 ROP, so it was of no consequence if the surgery used was scleral buckling surgery or lens-sparing vitrectomy. She also insisted that lensectomy-vitrectomy should be reserved only for stage 5 eyes with narrow funnel-type detachments, and that it was necessary to attempt a lens-sparing vitrectomy intervention before a tight funnel-type total retinal detachment could develop. Our data supported this, and also suggested some utility of the lens-sparing vitrectomy in stage 5 ROP patients with plus disease. However, in cases of open funnel-type retinal detachments, the lens-sparing vitrectomy resulted in rather disappointing outcomes, and it was associated with significant postoperative complications. Among the four patients who underwent lens-sparing vitrectomy for stage 5 ROP with plus disease, two later showed pupillary block glaucomas and one manifested a vitreous hemorrhage and a 115