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Updated: Jun 10, 2026

Three Different Protocols of Corneal Collagen Crosslinking in Keratoconus: Conventional, Accelerated and Iontophoresis
Published on: November 12, 2015
Baseline Demographics and Topographic Features in Keratoconic Eyes With Hydrops After Ipsilateral Prior Corneal
Priyanka Sudanaboina1, Sikha Misra2, Md Hasnat Ali3
1Cataract and Refractive Services, L.V. Prasad Eye Institute (LVPEI), Hyderabad, India.
Purpose:
To characterize the demographic and topographic features of patients with keratoconus who developed hydrops after a prior treatment with corneal cross-linking (CXL).
Methods:
Of the 4,967 eyes that had undergone accelerated epithelium-off CXL, acute hydrops occurred in 7 (0.14%) eyes of 7 patients in the follow-up period. Analysis of demographic and topographic features was performed.
Results:
The median age was 19 years (range: 17 to 23 years) and the male-to-female ratio was 5:2. The median mean keratometry (Km) was 57.70 diopters (D) (range: 51.80 to 60.70 D), maximum keratometry (Kmax) was 62.50 D (range: 55.10 to 68.10 D), and minimum pachymetry was 422 microns (range: 390 to 456 microns) before the CXL. The location of cone was central in all 7 eyes. At the visit preceding the occurrence of hydrops, the median Km was 54.50 D (range: 52.80 to 63.40 D), Kmax was 62.30 D (range: 57.40 to 79.00 D), and the minimum pachymetry was 375 microns (range: 313 to 404 microns). The median time from CXL to occurrence of hydrops was 39.3 months (range: 18.9 to 59.1 months). Although clinically there was flattening and reduction in pachymetry noted, there was no statistically significant difference in the keratometry and pachymetry values from baseline to after CXL. No significant antecedent history of coughing, sneezing, or eye rubbing could be elicited.
Conclusions:
The occurrence of hydrops after CXL is rare. Eye rubbing associated with allergic conditions is the specific predisposition. A clinically noteworthy feature was a reduction in pachymetry in eyes that developed hydrops. Due to the rarity of hydrops following prior CXL, reporting this event and reviewing the clinical and topographic features may enhance understanding in future studies.
