Purpose:
To examine the post-op GC response after uncomplicated PRK and LASIK.
Methods:
Dry eye (DE) questionnaire, Schirmer test, tear breakup time, and Rose Bengal staining were tested pre- and post-op. Patients whose post-op course was complicated by DE were excluded. Impression cytology samples (ICS) were taken from the superior and temporal conjunctivae of 12 PRK (8F, 4M) and 8 LASIK patients (3F, 5M) pre-op and at 1W, and 1 and 3M post-op. ICS were fixed on glass slides and stained with three indicators: DAPI to mark cell nuclei to determine the total number of cells (GC and squamous epithelial cells); with anti-keratin 7 (K7) to mark GC bodies to determine the percentage of cells which were GC (% GC); and with K7 and helix pomatia agglutinin to mark GC secretory product to determine the percentage of GC which were filled (% Filled GC). (Figure) Five random areas were selected as representative fields of the total slide. Results were compared using RM-ANOVA with p<0.05 considered significant.
Results:
Mean age±SD of the PRK group was 28.5±5.1 and LASIK was 32.8±5.1 years (p=0.18). Mean ablation depth of PRK was 55.40±18.10µm and LASIK was 56.01±17.85µm (p=0.91). The % GC did not change significantly over time in either the PRK group [46.2 ±27.6% pre, 34.8±22.7% 1W, 41.8±25.9% 1M, 45.5±21.9% 3M (p=0.43)] or the LASIK group [35.6 ±20.6% pre, 22.8±19.8% 1W, 17.4±14.9% 1M, 36.5±22.8% 3M (p=0.18)]. The % Filled GC did not change significantly over time in either the PRK group:64.7±35.4% pre, 80.1±17.9% 1W, 76.6±20.9% 1M, 68.0±33.2% 3M (p=0.29) or the LASIK group: 55.3 ±36.9% pre, 74.4±22.1% 1W, 70.3±27.6% 1M, 64.0±27.5% 3M (p=0.24).
Conclusions:
Preliminary results indicate that neither the percentage of GC nor the proportion of GC which are filled changes significantly over time after either PRK or LASIK in patients uncomplicated by post-op DE. GC response in post-surgical DE patients is currently under investigation.
Clinical Trial:
www.clinicaltrials.gov NCT00411827
Keywords: cornea: tears/tear film/dry eye • conjunctiva • refractive surgery