ABSTRACT
PURPOSE: To report the impact of establishing and maintaining a high intracameral pressure (ICP) of 200 mmHg on UT-DSAEK graft preparation using an artificial anterior chamber pressuriser (ACP) control unit (Moria SA, Antony, France). METHOD: Retrospective laboratory and clinical study. Four paired donor corneas were mounted on an artificial anterior chamber and subjected to 70 mmHg ("low") and 200 mmHg ("high") ICP using an ACP system. The central corneal thinning rate was measured after 5 min using AS-OCT and the endothelial cell viability was analysed using trypan blue and live/dead staining following 70 mmHg and 200 mmHg ICP. Visual outcomes and complications in a clinical case series of nine patients with bullous keratopathy who underwent UT-DSAEK using 200 mmHg ICP during graft preparation are reported. RESULTS: Laboratory outcomes showed 2 ± 1% and 2 ± 2% dead cells following 70 mmHg and 200 mmHg ICP respectively. Percentage viability in the 70 mmHg group (52.94 ± 5.88%) was not found to be significantly different (p = 0.7) compared to the 200 mmHg group (59.14 ± 10.43%). The mean corneal thinning rate after applying 200 mmHg ICP was 27 ± 13 µm/min centrally (7.2%/min). In the clinical case series, two cases were combined with cataract surgery. Re-bubbling rate was 11%. At the last follow-up (259 ± 109 days), graft thickness was 83 ± 22 µm centrally, endothelial cell density was 1175 ± 566 cell/mm2 and the BCVA of 0.08 ± 0.12 logMAR was recorded with no episodes of rejection. CONCLUSION: ACP control unit for UT-DSAEK graft preparation helps in consistently obtaining UT-DSAEK grafts without compromising endothelial cell viability.
Subject(s)
Corneal Diseases , Descemet Stripping Endothelial Keratoplasty , Anterior Chamber/surgery , Corneal Diseases/diagnosis , Corneal Diseases/surgery , Endothelium, Corneal , Humans , Retrospective Studies , Tissue DonorsABSTRACT
PURPOSE: To assess the refractive accuracy of different formulas for intraocular lens (IOL) power calculation in eyes with keratoconus. SETTING: IRCCS Fondazione Bietti, Rome, Italy. DESIGN: Multicenter retrospective interventional study. METHODS: A consecutive series of eyes with keratoconus that had cataract surgery were evaluated. Keratometry, anterior chamber depth, and axial length were measured preoperatively with optical biometry; IOL power was calculated with the Barrett Universal II, Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. Subjective refraction was assessed at 1 month. The mean prediction error (PE), median absolute error (MedAE) and percentage of eyes with a PE within ±0.50 diopters (D), ±0.75 D, and ±1.00 D were calculated. RESULTS: The final spherical equivalent was -0.52 D ±1.61 (SD). In the whole sample (41 eyes), the mean PE was positive (hyperopic surprise) with all formulas; the lowest PE (0.91 D) and MedAE (0.62 D) were obtained with the SRK/T formula. In stage I eyes (n = 21), the MedAE ranged between 0.43 and 0.91 D; the SRK/T formula achieved the lowest MedAE and the highest rate of eyes with a PE within ±0.50 (61.9%). In stage II eyes (n = 13), the MedAE ranged between 0.75 D and 1.50 D; the SRK/T formula achieved the lowest MedAE and the highest rate of eyes with a PE within ±0.50 (30.8%). In stage III eyes (n = 7), the MedAE was higher than 2.50 D with all formulas. CONCLUSIONS: In keratoconus eyes, all formulas led to a hyperopic refractive outcome. The SRK/T was the most accurate formula. The results were worse in advanced stages of the disease.
