Altered Corneal Nerves in Aqueous Tear Deficiency Viewed by In Vivo Confocal Microscopy

PURPOSE

To define the alterations of corneal nerves in aqueous tear deficiency dry eye patients with or without Sjögren syndrome and to identify the relationship between the morphologic changes of corneal nerves and the extent of dry eye.

METHODS

Confocal microscopy was used to examine 38 consecutive aqueous tear deficiency patients (8 Sjögren syndrome and 30 non-Sjögren syndrome) and 30 age- and gender-matched normal controls. Images taken by Confocal2 slit-scanning microscope at subbasal epithelial cell layer of central cornea were analyzed. The number and density of corneal nerves and their size, beads, tortuosity, and branching pattern were compared. These data were correlated with age and the degree of dry eye.

RESULTS

Sjögren syndrome patients showed a significant increase in average nerve number and tortuosity as compared with normal controls (P = 0.031 and 0.021, respectively). Severe nerve tortuosity (grade 4) and nerve branching appeared more frequently in aqueous tear deficiency than in normal subjects (P = 0.024 and 0.042, respectively). A decreased nerve number was observed with age in the normal controls (P = 0.002). However, such a correlation did not exist in aqueous tear deficiency. In aqueous tear deficiency, rose bengal staining score correlated positively with nerve density (P = 0.048) and nerve number (P = 0.001). Corneal fluorescein staining score was also positively correlated with nerve number (P = 0.027).

CONCLUSIONS

Abnormal morphologic changes are observed in aqueous tear deficiency that are more severe in Sjögren syndrome. The distinct changes of corneal nerves include increased nerve number, tortuosity, and chances of branching, suggesting an attempted nerve regeneration. A strong correlation exists between the changes of nerve morphology and the degree of dry eye. These results provide some possible evidence for the abnormal corneal sensation in dry eye.

Polar distribution dynamics of Con A binding sites in embryo sacs is temporally coupled by the fertilization process

The binding site distribution of concanavalin agglutinin (Con A) and wheat germ agglutinin (WGA) on embryo sacs at various developmental stages of Torenia fournieri L was studied by using a cooled Charge Coupled Device (CCD) and fluorescent Con A and WGA probes. The distribution patterns of Con A and WGA binding sites on embryo sacs changed during the fertilization process. The fluorescent signal indicating Con A binding sites was distributed evenly on the surface of the embryo sac wall before anthesis, was much denser on the micropylar end of the embryo sac wall and looked like a corona on the day of anthesis. After pollination, stronger fluorescence was present on the micropylar end of the embryo sac wall and the filiform apparatus (FA), showing an obvious polar distribution. When the pollen tube entered the embryo sac and reached a synergid, the fluorescence was still concentrated on the micropylar end and FA, and started to appear on the synergid. After fertilization, the polar distribution of the fluorescence gradually disappeared and an even distribution pattern was observed again on the embryo sac wall. These results revealed that the dynamic distribution of Con A binding sites was temporally coupled with the process of fertilization. WGA binding site distribution on the embryo sac was also investigated and showed a simple pattern but also regularly changed during the process of fertilization. The variation of these lectin binding sites during the fertilization process suggests that lectin binding site interactions may play a role in the process.

[Dry eye in graft-versus-host disease]

OBJECTIVE

To investigate patients who had ocular presentations after allogeneic hematopoietic stem cell transplantation.

METHODS

The eyes of 20 patients of leukemia who had undergone allogeneic hematopoietic stem cell transplantation were examined. The ocular surface of these patients was examined by slit-lamp. The eye examination also included evaluation of tear break-up time, Schirmer tests with and without nasal stimulation, and fluorescein staining, rose bengal staining, etc. Conjunctival impression cytology and pathological examination of surgical specimens from 3 patients were performed.

RESULTS

Fourteen of 20 patients developed chronic graft-versus-host disease (cGVHD). Eight patients suffered from dry eye accompanied by GVHD simultaneously. The incidence of dry eye in GVHD was 57%. Among them, 4 cases were severe dry eye associated with significant decrease of visual acuity and even development of corneal ulcer. Ophthalmic pathology findings were as follows: loss of conjunctival goblet cells or significant reduction in amount; conjunctival and corneal epithelial keratinization and squamous metaplasia; and dominance of T cell in conjunctival inflammatory infiltration cells.

CONCLUSION

Dry eye is the major ocular complication after allogeneic hematopoietic stem cell transplantation. It affected the patients' life quality severely. The high incidence and potentially severe ocular problems in these patients suggest that close ophthalmic monitoring is important in allogeneic hematopoietic stem cell transplantation.