A comparative study on clinical outcomes of penetrating keratoplasty for diabetes versus non-diabetes fungal keratitis patients

Background

Fungal keratitis is one of the main leading cause of blindness in China, the incidence of which is increasing year by year, while fungal keratitis with diabetes mellitus (DM) also has an increasing trend.Penetrating keratoplasty (PKP) is an effective treatment for fungal keratitis with high risks, but the study on clinical effect of diabetes mellitus on PKP is still relatively scarce.

Objective

The clinical data of 92 cases of fungal keratitis with DM and 106 cases of fungal keratitis without systemic disease who underwent PKP were retrospectively reviewed, and the postoperative best corrected visual acuity (BCVA), implant rejection, fungus recurrence, complicated cataract and secondary glaucoma were analyzed and compared.

Results

Moderate and severe infection were obtained in corneas of the two groups, the eye number distributions of different infection degree and Eurotium infection were not significantly different between the two groups (χ²=0.166, P=0.684). The eye number distributions of Eurotium infection had no statistical significance between the two groups(χ²=0.340, P=0.854). The eye number distributions of Fusarium and Candida infection were significantly different between the two groups (χ²=2.068, P=0.010; χ²=3.874, P=0.049) The BCVA of the 2 groups from 1 week to 2 years postoperative were all higher than preoperative.The numbers of patients whose BCVA>0.3 in fungal keratitis with DM group were significantly lower than those in the fungal keratitis without DM group in different time intervals after surgery (all at P<0.05). The implant rejection rate was 42.39% in the fungal keratitis with DM group, which was significantly higher than 28.30% in the fungal keratitis without DM group (χ²=4.306, P=0.038). The fungus recurrence rate was 17.39% in the fungal keratitis with DM group, which was significantly higher than 9.43% in the fungal keratitis without DM group (χ²=3.941, P=0.047). In addition, the proportion of complicated cataract patients in fungal keratitis with DM group was 9.78%, which was also higher than 2.83% in fungal keratitis without DM group (χ²=4.182, P=0.041). The incidences of secondary glaucoma were 5.43% and 7.54% for fungal keratitis with and without DM, respectively, no significant difference was obtained between the two groups (χ²=0.358, P=0.055). The reject reaction, fungus recurrence rates and incidences of complication were not significantly changed among different blood sugar level groups( all at P>0.05).

Conclusions

Compared with fungal keratitis patients without DM, fungal keratitis patients with DM have lower visual improvement, higher rate of implant rejection, fungus recurrence and complicated cataract after PKP.DM is a risk factor of complications after PKP.

Diabetes/complication; Keratoplasty, penetrating; Eye infections, fungal/surgery; Treatment outcomes; Retrospective studies