Table 2

Risk of corneal ulcers in the atopic keratoconjunctivitis and control groups

Atopic keratoconjunctivitisControls
CharacteristicsNCorneal ulcerPYRate*NCorneal ulcerPYRate*IRR (95% CI)P value
All corneal ulcer171 0192018965 428209.03171 01914811 008 697146.821.42 (1.33 to 1.52)<0.0001
Marginal corneal ulcer11511.92696.841.74 (1.29 to 2.35)0.0003
Infectious cornel ulcer1903197.111412139.981.41 (1.31 to 1.51)<0.0001
Age group (years)
 <1234 958214205 512104.1334 958247245 589100.571.04 (0.86 to 1.24)0.7099
 12–1925 470583142 722408.4925 470415143 300289.601.41 (1.24 to 1.60)<0.0001
 20–2933 397527192 011274.4633 397388192 755201.291.36 (1.20 to 1.55)<0.0001
 30–3928 620258159 130162.1328 620177159 880110.711.46 (1.21 to 1.77)<0.0001
 ≥4048 574436266 053163.8848 574254267 17495.071.72 (1.48 to 2.01)<0.0001
Sex
 Male70 942658401 291163.9770 942462426 631108.291.51 (1.34 to 1.71)<0.0001
 Female100 0771360564 136241.08100 0771019582 066175.071.37 (1.27 to 1.49)<0.0001
City status
 Metropolis119 4821510662 604227.89123 8641154729 103158.281.44 (1.33 to 1.55)<0.0001
 Satellite14 55914478 759182.8415 27311190 238123.011.49 (1.16 to 1.90)0.0017
 Rural36 978364224 066162.4531 882216189 356114.071.42 (1.20 to 1.69)<0.0001
Comorbidity
 Diabetes mellitus1535197829242.69153587840102.042.38 (1.04 to 5.43)0.0398
 Chronic renal disease2721341492.52701140
 Topical steroid ophthalmic agent146 8221738835 697207.9725 574299151 937196.791.06 (0.94 to 1.19)0.3775
 Lid margin disease917164890327.2031061773338.410.97 (0.38 to 2.47)0.9439
 Keratoconjunctivitis sicca675133616359.5124191226734.090.49 (0.21–1.15)0.0997
 Ocular blunt trauma357161867856.991292682293.262.92 (0.67 to 12.70)0.1530
 Post-corneal transplantation43121846521.74224924347.831.51 (0.49 to 4.67)0.4785
  • *Rate: per 100 000 PY.

  • A Poisson regression analysis was performed to calculate the IRR.

  • IRR, incidence rate ratio; PY, person-years.