In vitro characteristics of Tenon's fibroblast lines derived from pediatric and adult eyes do not fully explain pediatric glaucoma surgery failure: a preliminary report

PurposeTo compare the in vitro characteristics of Tenon's capsule fibroblasts from children and adults that may be relevant to filtration surgery success.MethodsFibroblast cell lines derived from 5 young (median patient age, 2.4 years) and 7 old (median patient age, 71 years) discarded Tenon's capsule surgical specimens were used at early passage (P2-P3). Fibroblasts were plated at “high” (104cells/cm2) or “low” density (103cells/cm2) and harvested at days 0-14, for growth curve and doubling time comparisons. Migration was measured using a wound model (confluent monolayers ± 5-fluorouracil [5-FU] over 1-96 hours). Collagen synthesis was measured as secreted hydroxyproline/24 hours from confluent monolayers.ResultsAt low density, “young” fibroblasts achieved higher cell numbers at confluence (day 14) compared with “old”: 158 ± 35 versus 105 ± 12 × 103cells/cm2 (P = 0.0034). Mean doubling time for young versus old was similar at low density plating: 20.95 ± 1.55 versus 22.37 ± 2.09 hours (P = 0.26). It was shorter, however, for young versus old at high-density plating: 42.11 ± 6.01 versus 54.26 ± 4.24 hours (P = 0.0051). Wound closure rates were similar for young versus old cells (4 lines for each group) with and without 5-FU. Collagen synthesis was similar for young and old (4 lines for each group).ConclusionsAlthough young fibroblasts reached higher density than old at confluence and had shorter doubling times at high-density plating, wound closure/migration and collagen synthesis rates were similar. Despite the preliminary nature of this study (few specimens, limited cell features explored), factors besides those intrinsic to the fibroblasts themselves likely mediate the more rapid healing/scarring after glaucoma filtration surgery in children.