Xiao-di Qiu1, Lan Gong, Min-jie Chen. 1. Department of Ophthalmology, Eye Ear Nose and Throat Hospital of Fudan University, Shanghai 200031, China.
Abstract
OBJECTIVE: Randomized controlled experimental study to investigate the influence of vitamin A palmitate and bovine recombinant basic fibroblast growth factor (bFGF) on repair of mechanical corneal epithelial defects, conjunctival epithelial cells and goblet cells in rabbits. METHODS: One hundred and twenty New Zealand rabbits (all males) were selected to establish the mechanical corneal epithelial defects models (scratching out a round area with the diameter of 8 mm in the centre of cornea). Forty eight New Zealand rabbits were randomly divided into 4 groups: group A used lincomycin hydrochloride eye drops (LED) after the model had been established; group B used vitamin A palmitate eye gel and LED; group C used recombinant bFGF eye gel and LED; group D used vitamin A palmitate eye gel, bFGF eye gel and LED. Photo slit lamp examination and measurement of repaired area were performed on day 0, day 1, day 4 and day 7; transmission electron microscopy, histological microscope examination and impression cytology were performed on day 0, day 1, day 4 and day 7 to analysis the morphology and repairment of corneal epithelium, conjunctival epithelial cells and the goblet cells. The variants were tested using analysis of variance and Tukey's test. RESULTS: Statistic analysis showed that on day 1, the size of areas of repaired corneal epithelium was: group A(53.512 +/- 18.850) mm(2), group B (92.194 +/- 14.367) mm(2), group C (89.779 +/- 20.535) mm(2), group D (127.816 +/- 16.379) mm(2). The difference in size of repaired areas between different groups was statistically significant (F = 17.663, P = 0.000), with exception of the difference between groups B and C (P = 0.995). Conjunctival impression cytology showed that, the average number of conjunctival goblet cells per 740 microm x 550 microm at day 1 was decreased, group A (10.083 +/- 4.441), group B (10.667 +/- 3.551), group C (9.583 +/- 4.502), group D (9.167 +/- 5.606). The difference between these four groups was not significant (F = 0.239, P = 0.868). At day 4, the size of areas of repaired corneal epithelium was: group A (120.369 +/- 11.839) mm(2), group B (156.606 +/- 8.087) mm(2), group C (154.216 +/- 9.990) mm(2), group D (175.181 +/- 5.168) mm(2), which showed a significant difference between each two groups (F = 37.665, P = 0.000), with exception between groups B and C (P = 0.968). The average number of goblet cells at day 4 was recovered, which was: group A (41.250 +/- 4.575), group B (56.083 +/- 6.374), group C (48.417 +/- 4.562), group D (61.917 +/- 5.017), with a significant difference between these four groups (F = 36.210, P = 0.000). At day 7, the size of areas of repaired corneal epithelium had a statistical significance (F = 32.656, P = 0.000) between these four groups, which was group A (177.472 +/- 3.585) mm(2), group B (186.715 +/- 3.022) mm(2), group C (182.293 +/- 3.158) mm(2), group D (194.106 +/- 2.176) mm(2). The area of repaired corneal epithelium in group D was larger than that of other groups (P < 0.05). The average number of goblet cells was recovered significantly, which was: group A (63.167 +/- 11.488), group B (99.501 +/- 15.877), group C (82.015 +/- 9.175), group D (104.750 +/- 9.659). There was a significant difference in goblet cell number between these groups (F = 30.312, P = 0.000) with exception between groups B and D (P = 0.700). In transmission electron microscope examination of the cornea, we found that vitamin A palmitate and bFGF could both promote the development of intracellular conjunction. Vitamin A palmitate protected corneal epithelial cells, prevented cell keratinization, promoted proliferation and differentiation of corneal epithelial cells. In transmission electron microscopy examination of the conjunctiva, conjunctival goblet cells in groups B and D recovered well with rich secretary granules, which were quite different from groups A and C. Conjunctival epithelium of groups B, C and D were well-differentiated with tight intracellular conjunction. CONCLUSIONS: Vitamin A palmitate and bFGF could promote the repair of mechanical corneal epithelial defects and the development of intracellular conjunction. The effect is more significant when vitamin A palmitate is combined with bFGF. Vitamin A palmitate promotes regeneration of conjunctival goblet cells and can re-establish intracellular conjunction of conjunctival epithelium. The protective effect of vitamin A palmitate on conjunctival goblet cells is better than that of bFGF.
OBJECTIVE: Randomized controlled experimental study to investigate the influence of vitamin A palmitate and bovine recombinant basic fibroblast growth factor (bFGF) on repair of mechanical corneal epithelial defects, conjunctival epithelial cells and goblet cells in rabbits. METHODS: One hundred and twenty New Zealand rabbits (all males) were selected to establish the mechanical corneal epithelial defects models (scratching out a round area with the diameter of 8 mm in the centre of cornea). Forty eight New Zealand rabbits were randomly divided into 4 groups: group A used lincomycin hydrochloride eye drops (LED) after the model had been established; group B used vitamin A palmitate eye gel and LED; group C used recombinant bFGF eye gel and LED; group D used vitamin A palmitate eye gel, bFGF eye gel and LED. Photo slit lamp examination and measurement of repaired area were performed on day 0, day 1, day 4 and day 7; transmission electron microscopy, histological microscope examination and impression cytology were performed on day 0, day 1, day 4 and day 7 to analysis the morphology and repairment of corneal epithelium, conjunctival epithelial cells and the goblet cells. The variants were tested using analysis of variance and Tukey's test. RESULTS: Statistic analysis showed that on day 1, the size of areas of repaired corneal epithelium was: group A(53.512 +/- 18.850) mm(2), group B (92.194 +/- 14.367) mm(2), group C (89.779 +/- 20.535) mm(2), group D (127.816 +/- 16.379) mm(2). The difference in size of repaired areas between different groups was statistically significant (F = 17.663, P = 0.000), with exception of the difference between groups B and C (P = 0.995). Conjunctival impression cytology showed that, the average number of conjunctival goblet cells per 740 microm x 550 microm at day 1 was decreased, group A (10.083 +/- 4.441), group B (10.667 +/- 3.551), group C (9.583 +/- 4.502), group D (9.167 +/- 5.606). The difference between these four groups was not significant (F = 0.239, P = 0.868). At day 4, the size of areas of repaired corneal epithelium was: group A (120.369 +/- 11.839) mm(2), group B (156.606 +/- 8.087) mm(2), group C (154.216 +/- 9.990) mm(2), group D (175.181 +/- 5.168) mm(2), which showed a significant difference between each two groups (F = 37.665, P = 0.000), with exception between groups B and C (P = 0.968). The average number of goblet cells at day 4 was recovered, which was: group A (41.250 +/- 4.575), group B (56.083 +/- 6.374), group C (48.417 +/- 4.562), group D (61.917 +/- 5.017), with a significant difference between these four groups (F = 36.210, P = 0.000). At day 7, the size of areas of repaired corneal epithelium had a statistical significance (F = 32.656, P = 0.000) between these four groups, which was group A (177.472 +/- 3.585) mm(2), group B (186.715 +/- 3.022) mm(2), group C (182.293 +/- 3.158) mm(2), group D (194.106 +/- 2.176) mm(2). The area of repaired corneal epithelium in group D was larger than that of other groups (P < 0.05). The average number of goblet cells was recovered significantly, which was: group A (63.167 +/- 11.488), group B (99.501 +/- 15.877), group C (82.015 +/- 9.175), group D (104.750 +/- 9.659). There was a significant difference in goblet cell number between these groups (F = 30.312, P = 0.000) with exception between groups B and D (P = 0.700). In transmission electron microscope examination of the cornea, we found that vitamin A palmitate and bFGF could both promote the development of intracellular conjunction. Vitamin A palmitate protected corneal epithelial cells, prevented cell keratinization, promoted proliferation and differentiation of corneal epithelial cells. In transmission electron microscopy examination of the conjunctiva, conjunctival goblet cells in groups B and D recovered well with rich secretary granules, which were quite different from groups A and C. Conjunctival epithelium of groups B, C and D were well-differentiated with tight intracellular conjunction. CONCLUSIONS:Vitamin A palmitate and bFGF could promote the repair of mechanical corneal epithelial defects and the development of intracellular conjunction. The effect is more significant when vitamin A palmitate is combined with bFGF. Vitamin A palmitate promotes regeneration of conjunctival goblet cells and can re-establish intracellular conjunction of conjunctival epithelium. The protective effect of vitamin A palmitate on conjunctival goblet cells is better than that of bFGF.