Post-DSAEK Optical Changes

Abstract

Purpose To assess the visual impact of ocular wavefront aberrations, corneal thickness, and corneal light scatter prospectively after Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK) in humans. Methods Data were obtained prospectively from 20 eyes pre-operatively and at 1, 3, 6, and 12 months post- DSAEK. At each visit, best spectacle corrected visual acuity (BSCVA) and visual acuity with glare (Brightness Acuity Testing - BAT) were recorded and ocular wavefront measurements and corneal Optical Coherence Tomography (OCT) performed. Magnitude and sign of individual Zernike terms (higher order aberrations HOA) were determined. Epithelial, host stromal, donor stromal, and total corneal thickness were quantified. Brightness, intensity profiles of OCT images were generated to quantify light scatter in the whole cornea, subepithelial region, anterior and posterior host stroma, interface, and donor stroma. Results Mean BSCVA and glare disability at low light levels improved from 1 to 12 months post-DSAEK. All corneal thicknesses and ocular lower- and HOAs were stable from 1 through 12 months, whereas total corneal, host stromal, and interface brightness intensities decreased significantly over the same period. A repeated measures ANOVA across the follow up period found that the change in scatter, but not the change in higher order aberrations, could account for the variability occurring in acuity from 1 to 12 months post-DSAEK. Conclusions While ocular HOAs and scatter are both elevated over normal post-DSAEK, our results demonstrate that improvements in visual performance occurring over the first year post-DSAEK are associated with decreasing light scatter. In contrast, there were no significant changes in ocular HOAs during this time. Because corneal light scatter decreased between 1 and 12 months despite stable corneal thicknesses over the same period, we conclude that factors that induced light scatter, other than tissue thickness or swelling (corneal edema), significantly impacted the visual improvements that occurred over time post-DSAEK. A better understanding of the cellular and extracellular matrix changes of the subepithelial region and interface, incurred by the surgical creation of a lamellar host -graft interface, and the subsequent healing of these tissues, is warranted.

Effect of Intraocular Forward Scattering and Corneal Higher-Order Aberrations on Visual Acuity after Descemet’s Stripping Automated Endothelial Keratoplasty

“…This may be attributed to the induction of higher-order aberrations (HOAs) and/or light scattering by the cornea, especially by the anterior stroma and the interface between the donor and recipient corneas. Although several studies on corneal or ocular HOAs after DSAEK have so far been published,[ 4 – 15 ] there are only a few studies on both HOAs and intraocular scattering, which play a major role in visual performance in post-DSAEK eyes. [ 13 , 15 ].…”

“…Although several studies on corneal or ocular HOAs after DSAEK have so far been published,[ 4 – 15 ] there are only a few studies on both HOAs and intraocular scattering, which play a major role in visual performance in post-DSAEK eyes. [ 13 , 15 ]. All these previous studies on intraocular scattering have been focused on the backward scattering of the cornea,[ 13 , 15 – 17 ] except for one study on the forward scattering of the eye, which plays a more essential role in visual performance than backward scattering, after DSAEK.…”

“…[ 13 , 15 ]. All these previous studies on intraocular scattering have been focused on the backward scattering of the cornea,[ 13 , 15 – 17 ] except for one study on the forward scattering of the eye, which plays a more essential role in visual performance than backward scattering, after DSAEK. [ 18 ] However, the measurement of forward light scatter or retinal stray light used in their study is a subjective psychophysical test, which can introduce variability into the results.…”

Endothelial Keratoplasty

“…52 İkinci neden; kronik ödeme bağlı olarak alıcı stromasında gelişen kollajen organizasyonundaki bozulma, keratosit dejenerasyonu ve subepitelyal fibrozdur. 53,54 Bu değişiklikler ödemin süresi ile orantılı olup, bir yıldan daha kısa süreli ödemlerde kısmen geri dönüşlüdür. Bu nedenle erken dönemde yapılan cerrahilerde final görmenin daha yüksek olduğu saptanmıştır.…”

Overview of Influence Factors on Corneal Thickness Measurement

“…On the other hand, if you claim your own view points, you can use "we believe" "we think") reported that the corneal thickness would be thinner after using mydriatic (Yuksel et al, 2014). Scholar Azartash K considered the corneal thickness of patients with xerophthalmia was thinner than that of healthy people (Azartash et al, 2011); some reports claimed that diabetes would also give rise to variation of corneal thickness (Urban et al, 2013;Tiutiuca, 2013;Zhang et al, 2013;Storr-Paulsen et al, 2014;Ozdamar et al, 2010) and the history of eye surgery would have an obvious effect on corneal thickness (Hindman et al, 2013).…”