To investigate the effect of severe desiccation on corneal thickness in scarring trachoma by comparing the thickness of normal and trachomatous dry eye corneas.
Methods
Ultrasonic pachymetry was used to measure the corneal thickness at nine points in the central and peripheral cornea (superior, superonasal, nasal, inferonasal, inferior, inferotemporal, temporal, superotemporal) in 45 eyes of 27 patients with trachomatous dry eye and 54 eyes of 31 normal subjects.
Results
The average thickness of the nine sites in the central and midperipheral cornea was significantly less in trachomatous dry eyes than normal eyes. The superior cornea was the thickest area in both groups, measuring 574.03 ± 31.62 μm in trachomatous dry eyes and 611.33 ± 34.99 μm in normal eyes (p<0.001). The centre of the cornea was the thinnest, measuring 510.43 ± 32.12 μm in trachomatous dry eyes and 546.27 ± 36.20 μm in normal eyes (p<0.001).
Conclusions
The thickness of the central and midperipheral cornea was significantly reduced in patients with trachomatous dry eye. The chronic state of severe desiccation, tear film instability and increased immune activation in trachomatous dry eye may contribute to this thinning.(Eur J Ophthalmol 2002; 12: 18–23)
JohnsonM.H., RogerL., BolzR.L., GodioL.B.. Deswelling of the cornea after hypoxia.Am J Optom Physiol Opt1985; 62: 768–73.
2.
EfronN., CarneyL.G.. Oxygen levels beneath the closed eyelid.Invest Ophthalmol Vis Sci1979; 18: 93–5.
3.
KlyceS.D.. Stromal lactate accumulation can account for corneal oedema osmotically following epithelial hypoxia in the rabbit.J Physiol1981; 312: 49–64.
4.
HansenF.K.. A clinical study of the normal human central corneal thickness.Acta Ophthalmol1971; 49: 82–9.
5.
FarrisR.L., StuchellR.N., MandelI.D.. Basal and reflex human tear analysis. I. Physical measurements: Osmolarity, basal volumes and reflex flow rate.Ophthalmology1981; 88: 852–7.
6.
RolandoM., RefojoM.G., KenyonK.R.. Increased tear evaporation in eyes with keratoconjunctivitis sicca.Arch Ophthalmol1983; 101: 557–8.
ThyleforsB., DawsonC.R., JonesB.R., WestS.K., TaylorH.R.. A simple system for the assessment of trachoma and its complications.Bull World Health Organ1987; 65: 447–83.
TsengS.C.G.. Staging of conjunctival squamous metaplasia by impression cytology.Ophthalmology1985; 92: 728–33.
11.
HarperC.L., BoultonM.E., BennettD.. Diurnal variations in human corneal thickness.Br J Ophthalmol1996; 80: 1068–72.
12.
HollyF.J.. Diagnostic methods and treatment modalities of dry eye conditions.Int Ophthalmol1993; 17: 113–25.
13.
DanyoY., HamanoT.. Observation of precorneal tear film in patients with Sjögren's syndrome.Acta Ophthalmol1995; 73: 501–5.
14.
FarrisR.L.. The dry eye: its mechanisms and therapy.CLAO J1986; 12: 234–46.
15.
GuzeyM., OzardaliI., BasarE., AslanG.. A survey of trachoma: The histopathology and the mechanism of progressive cicatrisation of eyelid tissues.Ophthalmologica2000; 214: 277–84.
16.
TabbaraK.F., BobbA.A.. Lacrimal system complications in trachoma.Ophthalmology1980; 87: 298–301.
17.
Al-RajhiA.A., HidayatA., NasrA., Al-FaranM.. The histopathology and the mechanism of entropion in patients with trachoma.Ophthalmology1993; 100: 1293–6.
18.
TiffanyJ.M.. The role of meibomian secretion in the tears.Trans Ophthalmol Soc UK1985; 104: 396–401.
19.
HollyF.J., LempM.A.. Tear physiology and dry eyes.Surv Ophthalmol1977; 22: 68–87.
20.
WilsonS.E., HeY., WangJ.. Epithelial injury induces keratocyte apoptosis: hypothesized role for the interleukin -1 system in the modulation of corneal tissue organization and wound healing.Exp Eye Res1996; 62: 325–37.
21.
WilsonS.E., KimW.J.. Keratocyte apoptosis: implications on corneal wound healing, tissue organization, and disease.Invest Ophthalmol Vis Sci1998; 39: 220–6.
22.
WilsonS.E., HeY.G., LloydS.A.. EGF, EGF receptor, basic FGF, TGF beta-1, and IL-1 alpha mRNA in human corneal epithelial cells and stromal fibroblasts.Invest Ophthalmol Vis Sci1992; 33: 1756–65.
NakayasuK.. Stromal changes following removal of epithelium in rat cornea.Jpn J Ophthalmol1988; 32: 113–25.
25.
CamposM., SzerenyiK., LeeM., McDonnellJ.M., McDonnellP.J.. Keratocyte loss after corneal deepithelialization in primates and rabbit.Arch Ophthalmol1994; 112: 254–60.
26.
GirardM.T., MatsubaraM., ElizabethF.M.. Transforming growth factor-β and interleukin-1 modulate mettalloproteinase expression by corneal stromal cells.Invest Ophthalmol Vis Sci1991; 32: 2441–54.
27.
SakamotoS., InadaK., ChibaK., YoshidaM., TazawaY.. Production of IL-6 and IL-1α by human corneal epithelial cells.Acta Soc Ophthalmol Jpn1991; 95: 728–32.
28.
SakamotoS., InadaK.. Human corneal epithelial, stromal and endothelial cells produce interleukin-6.Acta Soc Ophthalmol Jpn1992; 96: 702–9.
29.
CubittC.L., TangQ., MonteiroC.A., LauschR.N., OakesJ.E.. IL-8 gene expression in cultures of human corneal epithelial cells and keratocytes.Invest Ophthalmol Vis Sci1993; 34: 3199–206.
30.
GilbardJ.P., FarrisR.L., SantamariaJ.. II. Osmolarity of tear microvolumes in keratoconjunctivitis sicca.Arch Ophthalmol1978; 96: 677–81.
31.
PrydalJ.I., ArtalP., WoonH., CampbellF.W.. Study of human precorneal tear film thickness and structure using laser interferometry.Invest Ophthalmol Vis Sci1992; 33: 2006–11.
32.
HovdingG.. The central corneal thickness in keratoconjunctivitis sicca.Acta Ophthalmol1992; 70: 108–10.
33.
LiuZ., PflugfelderS.C.. Corneal thickness is reduced in dry eye.Cornea1999; 18: 403–7.
34.
PoleJ.J., BatzerJ.K.. Central corneal thickness of patients with dry eyes.J Am Optom Assoc1985; 56: 220–1.
35.
van BijsterveldO.P., BaardmanJ.. Measurement of corneal thickness in patients with keratoconjunctivitis sicca.Klin Monatsbl Augenheilkd1990; 197: 240–3.
36.
JonesD.T., JiA., MonroyD., PflugfelderS.C.. Evaluation of ocular surface cytokine, mucin and cytokeratin expression in Sjögren's Syndrome.Adv Exp Med Biol1998; 438: 533–6.
