Penetrating Keratoplasty In Eyes Research Articles

A Detailed Analysis of Individuals Having Graft Failure After Corneal Transplantation

ABSTRACT Purpose To describe demographic and clinical characteristics of patients with graft failure after keratoplasty, determine the cause of graft failure and outcomes. Methods The charts of patients between 2008–2013 in the Cornea Service at Wills Eye Hospital with a history of a corneal transplant before the end of 2012 were retrospectively reviewed. Included were patients who had graft failure after corneal transplantation and had at least one year of follow-up after transplantation. Penetrating keratoplasty (PK) and Descemet’s stripping endothelial keratoplasty (DSEK) patients were analyzed separately. Results A total of 186 eyes of 170 patients with graft failure after a PK (156) or DSEK (30) procedures were identified. The baseline characteristics included 100 female and 70 male patients with an age between 0 and 90 years (median 63 years). At the time of surgery, 38% had three or more systemic diseases and 68% were using three or more systemic medicines. Mean follow up time for PK was nearly four times of DSEK. Only 2 DSEK eyes (7%) underwent a 3rd DSEK graft, while 47 (30%) PK eyes underwent a 3rd PK and 15 (10%) PK eyes underwent more than three PK procedures. Conclusions Most DSEK failures occurred in 1st year, while graft failure in PKs is scattered over years. Failure in DSEK is mostly due to graft or surgical risk factors but in PK mostly due to factors in the host. DSEK does not appear to be as affected by the patients’ demographic and clinical characteristics as much as PK.

Deep Anterior Lamellar Keratoplasty-Treated Keratoconic Eyes With Descemet Membrane Rupture.

The aim of this study was to evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) and compare it with penetrating keratoplasty (PKP) in keratoconic eyes with Descemet membrane (DM) rupture. In this comparative retrospective case series, 33 keratoconic eyes with a history of hydrops underwent DALK and 27 received PKP. Baseline and postoperative visual acuity, corneal astigmatism, mean keratometry, endothelial cell density, and complication rates were measured. The median follow-up of patients who underwent DALK was 45 months (range, 4-76 months) and that of patients who underwent PKP was 84 months (range, 4-136 months). Both procedures had comparable postoperative visual acuity, astigmatism, and mean keratometry. Significantly higher endothelial cell densities were observed in DALK than in PKP at 2, 3, and 5 years postsurgery (2043 ± 767 vs. 1165 ± 683 cell/mm2, P = 0.007, n = 12 in both groups at 2 years). Intra-DALK, 15 perforations occurred (44.12%) and 1 (2.94%) was converted to PKP. Graft rejection was diagnosed in 1 (3.03%) DALK procedure versus 8 (29.63%) PKP (P = 0.008), and other long-term complication rates were equivalent. Kaplan-Meier survival analysis also revealed a higher rejection-free survival rate for the DALK group (P = 0.012). Subgroup analysis within both groups based on the severity of preoperative DM rupture revealed no significant difference in any major 2-year outcomes. DALK showed similar beneficial visual outcome and safety but significantly better endothelial protection over PKP in eyes with keratoconus and previous hydrops. Therefore, DALK is recommended in posthydrops cases irrespective of the DM rupture severity.

Comparison of penetrating keratoplasty versus lamellar keratoplasty for macular corneal dystrophy: a retrospective study of a single-center experience

Background: Although penetrating keratoplasty (PK) still remains the dominant form of transplantation for macular corneal dystrophy (MCD) patients, many studies evaluating these new forms of selective lamellar keratoplasty (LK) now suggest equivalent or better visual outcomes. This study aimed to explore the difference in outcomes and complications that follows each type of these operations. Methods: A retrospective, single-center study was performed at King Abdulaziz medical city in 2022. The study included patients with a histological diagnosis of MCD who undergone either PK or LK. Data was collected from health records using a form that consisted of patient characteristic, type of operation and post-operative outcomes, including visual acuity, survival rate and complications. Results: The study included a total of 54 eyes of patients who have MCD. A best corrected visual acuity (BCVA) of 0.5 or better was achieved in 82.5% of eyes of PK group and 42.9% of eyes of LK group. Graft survival rate was 90% (36 eyes) and 85.7% (12 eyes) in PK and LK groups respectively. Regarding complications, four PK eyes (10%) and one LK eye (7.1%) had high intraocular pressure, three PK eyes (7.5%) and one LK eye (7.1%) developed rejection, one PK eye (2.5%) developed recurrent epithelial erosion, and another one PK eye (2.5%) developed Traumatic epithelial laceration. Conclusions: PK operations resulted in a better post-operative visual acuity compared to LK group. The graft survival rate was slightly better for the PK group. PK was associated with higher incidence of complications than LK group.

Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty for Advanced Stage of Keratoconus

To compare visual acuity, refractive error, and complications after penetrating keratoplasty (PK) versus deep anterior lamellar keratoplasty (DALK) in the management of advanced stage of keratoconus. Retrospective, comparative, interventional study. This study enrolled 411 consecutive keratoconus eyes with preoperative mean keratometry ≥60 D that received either PK (218 eyes) or DALK (193 eyes). The outcome measures were postoperative visual acuity, refraction, complications, and further surgical interventions. The mean follow-up duration was 77.9±46.5 and 72.9±47.8 months in the PK and DALK groups, respectively (P=0.28). Compared to baseline values, postoperative visual acuity and refraction significantly improved in both groups. Postoperative corrected distance visual acuity was 0.18±0.13 and 0.26±0.19 logMAR in the PK and DALK groups, respectively (P<0.001). Postoperative spherical equivalent refraction was -2.89±2.89 D after PK and -4.58±3.62 D after DALK (P<0.001). Final keratometric astigmatism was comparable between the two groups (P=0.82). Suture-related complications were observed in 48.6% of the PK eyes and 72.0% of the DALK eyes (P<0.001). The incidence of graft rejection was 33.5% after PK and 19.7% after DALK (P=0.002). At the last visit, 98.2% of PK grafts and 94.8% of DALK grafts remained clear (P=0.06). Both techniques of corneal transplantation led to a significant improvement in the visual and refractive variables in eyes with advanced keratoconus. PK resulted in a better visual acuity and refraction with less suture-related complications compared to DALK. However, PK was associated with higher rate of graft rejection. The two techniques were comparable in terms of graft survival.

Toric intraocular lenses for astigmatism correction after keratoplasty in phakic and pseudophakic eyes.

Residual astigmatism and anisometropia significantly affect patients' vision and quality of life even in clear grafts after corneal transplant. This study reviewed and summarized the role of toric intraocular lenses (IOLs) in phakic and pseudophakic eyes after penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty in correcting residual astigmatism. 342 eyes from 20 studies with iris-clipped toric IOL, ciliary sulcus toric implantable collamer lens, piggyback sulcus toric IOL, or posterior chamber toric IOL implantations for phakic, pseudophakic, or eyes undergoing cataract surgery after keratoplasty were included. Visual, refractive, and predictability outcomes were encouraging. Secondary realignment rate and complications were low. Endothelial cell loss secondary to phakic toric IOLs might be a concern over the long-term, particularly in iris-clipped IOLs in PKP eyes. Toric IOLs represent a viable option in the treatment of residual astigmatism in postkeratoplasty eyes, resulting in improved visual acuity and reduced anisometropia.

Corneal Biomechanics and Intraocular Pressure Following Scleral Lens Wear in Penetrating Keratoplasty and Keratoconus.

To compare corneal biomechanics and intraocular pressure (IOP) in keratoconus and penetrating keratoplasty eyes before and after nonfenestrated scleral lens wear. Twenty-three participants were enrolled, and 37 eyes were included in the analysis (11 penetrating keratoplasty and 26 keratoconus). A range of corneal biomechanical parameters and IOP were measured using the CORVIS ST before and after 8 hr of nonfenestrated scleral lens wear (Keracare, Acculens, Denver, CO). Before lens wear, penetrating keratoplasty eyes displayed significantly greater median values for central corneal thickness (97 μm thicker, P=0.02), IOP (3.89 mm Hg higher, P=0.01), and biomechanical parameter A2 length (0.48 mm longer, P=0.003) compared with keratoconic eyes. No significant changes in corneal biomechanical parameters or IOP were observed after scleral lens wear in either group (all P>0.05). Although nonfenestrated scleral contact lenses can induce a subatmospheric pressure after lens settling and compress tissue surrounding the limbus, no significant changes were detected in the corneal biomechanical parameters studied using CORVIS ST after scleral lens wear in eyes with penetrating keratoplasty and keratoconus.

Outcomes of Ahmed Glaucoma Valve Implantation in Eyes with Pediatric Keratoplasty

This study aimed to assess the efficacy and safety of Ahmed glaucoma valve (AGV) (New World Medical Inc.) implantation in eyes with pediatric keratoplasty and glaucoma. Retrospective, noncomparative, interventional case series. Twenty-eight eyes of 25 children who underwent AGV after penetrating keratoplasty (PK) in 22 eyes and Descemet's stripping endothelial keratoplasty (DSEK) in 6 eyes were included. Children (age ≤ 16 years) treated with AGV implant after keratoplasty from 2008 to 2019 with documented 6 months follow-up operated by a single surgeon were included. The primary outcome measure was AGV survival (intraocular pressure [IOP] between 6 and 21 mmHg with or without topical anti-glaucoma medications [AGMs]), and the secondary outcome measure was corneal graft survival. The mean age (± standard deviation) of patients at AGV surgery was 4.8 ± 0.7 years. The meanfollow-up after AGV was 3.4 ± 0.5 years. The mean IOP decreased significantly from 31.5 ± 2.0 mmHg to 21.1 ± 2.3 mmHg at 6 months postsurgery (P < 0.001). The mean number of AGM decreased significantly (P<0.001), and there was no change in mean visual acuity (P > 0.04 with Bonferroni correction). The cumulative survival probability of AGV was 92.9% ± 4.9% at 1 year and 81.3% ± 11.7% at 5 years. The AGV success wascomparable between PK and DSEK eyes (P= 0.73). The cumulative probability of graft survival was 96.2%±3.8% at 1 year and 77.8% ± 9.1% at 5 years. The graft survival was also comparable between PK and DSEK eyes (P= 0.18). One eye needed tube trimming; none had tube or implant exposure. The major complication noted was corneal graft infection in 8 eyes (28.5%). In this cohort, the long-term AGV success and graft survival outcomes are satisfactory considering that AGV was performed in complex eyes with keratoplasty.

Medium-Term Clinical Outcomes of Deep Anterior Lamellar Keratoplasty versus Penetrating Keratoplasty for Macular Corneal Dystrophy.

PurposeTo compare the postoperative outcomes of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP) for macular corneal dystrophy (MCD).DesignSingle-center, retrospective, interventional case series.MethodsA chart review was performed of 100 patients (157 eyes) who underwent primary DALK (DALK group) and PKP (PKP group) for histopathologically confirmed MCD for whom at least 12 months of follow-up were available. Between-group comparisons were performed of visual acuity (VA), graft survival, and postoperative complications.ResultsThere were 22 eyes in the DALK group and 135 in the PKP group. Postoperative best-corrected visual acuity (BCVA) of 20/40 or better was achieved in 90.9% of the DALK group and 76.3% of the PKP group (P=0.12). At last visit, graft survival was 95.5% (21 eyes) and 91.1% (123 eyes) in DALK and PKP groups, respectively (P=0.69, Log rank test). Corneal graft rejection episodes occurred in 1 (4.5%) DALK graft and 19 (14.1%) PKP grafts. Five of the 19 graft rejections in the PKP group were irreversible. Microbial keratitis and cataract occurred in 6 (4.5%) and 15 (11.1%) PKP eyes. One (4.5%) eye in the DALK group had cataract and none of the DALK cases developed microbial keratitis. Clinically significant recurrence was observed in 4 (2.9%) PKP eyes and 1 (4.5%) DALK eye (P=0.69), respectively.ConclusionDALK is a viable option for MCD without Descemet membrane involvement. DALK had comparable medium-term visual and survival outcomes to PKP. DALK has the advantage of lower open sky intraoperative complications and lower graft rejection episodes.

Reliability of Several Glaucoma Tests in Patients With Boston Type 1 Keratoprosthesis.

Managing glaucoma after Boston type 1 keratoprosthesis (KPro) surgery remains challenging. We herein assessed the fitness of commonly used clinical tests to evaluate glaucoma in KPro eyes versus eyes with penetrating keratoplasty (PK) as controls. Sixteen patients with KPro and 14 patients with PK tested in an identical manner. After the 10-2 visual field with size V stimulus, intraocular pressure (IOP) was estimated with palpation by the first observer. Then, retinal nerve fiber layer (RNFL) thickness analysis was performed twice using optical coherence tomography by an ophthalmic photographer, before and after a short break. After the second observer estimated the IOP, the visual field was repeated. Finally, color photographs of the optic disk were captured by an ophthalmic photographer. The cup-to-disk ratio was assessed by 2 masked observers, at 2 different time points, in a random manner. Agreements between and within observers and reliability of repeated measurements were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Inter-rater agreement of palpation IOP estimate was moderate for eyes with KPro (ICC = 0.47) and fair for eyes with PK (ICC = 0.27). Visual field and RNFL thickness showed high test-retest reliability in both KPro and PK eyes (ICC > 0.80 for both). Inter-rater agreement of cup-to-disk ratio assessments was substantial in eyes with both KPro (ICC = 0.62) and PK (ICC = 0.70). The 10-2 visual field and RNFL thickness seem sufficiently repeatable and might allow the detection of glaucoma progression in KPro eyes. Such testing is important, given limited inter-rater agreement regarding the palpation IOP estimate.

Comparison of the iCare, Tono-Pen, non-contact airpuff, and Goldmann applanation tonometers in eyes with corneal edema after penetrating keratoplasty.

To compare the utility of the iCare, Tono-Pen, and non-contact airpuff (NCT) tonometers with the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP) in patients with corneal edema after penetrating keratoplasty (PKP) and to assess the effects of central corneal thickness (CCT) and corneal curvature (CC) on IOP measurements. Thirty-two eyes of 27 patients with corneal edema after PKP due to corneal abnormalities and 43 control eyes of 30 patients with normal corneas were recruited. Before IOP measurements, all patients underwent a baseline examination, including auto-refraction, keratometry, slit lamp biomicroscopy, and CCT measurement. IOP was measured using the devices in the same order: first the NCT, followed by the iCare, Tono-Pen, and GAT. The differences between the iCare, Tono-Pen, NCT, and GAT were calculated with repeated-measures analysis of variance. The Bland-Altman method was used to assess the agreement between the iCare, Tono-Pen, and NCT versus the GAT. The influences of CCT and CC on IOP measurement were evaluated by correlation analysis using Pearson's correlation coefficient. Mean IOP measurements were significantly higher with the NCT and Tono-Pen than with the GAT in the PKP and control groups. When compared with GAT, iCare showed significantly higher IOP readings in the control group, but the IOP readings did not differ between the iCare and GAT in the PKP group. Poor agreement was noted between the NCT and GAT in both groups. The Tono-Pen showed clinically acceptable agreement with GAT in control eyes and poor agreement in PKP eyes. The agreement between the iCare and GAT appeared to be clinically acceptable in both groups. Correlation analysis of the results from control eyes showed that the IOP measurements with the GAT and NCT were weakly related to CCT and moderately correlated with CC. The iCare IOP readings were weakly correlated with CCT and CC. In the PKP group, the NCT and Tono-Pen significantly overestimated IOP, whereas the iCare IOP readings were similar to those obtained using the GAT. Poor agreement was noted between the NCT and GAT as well as between the Tono-Pen and GAT, but the iCare showed clinically acceptable agreement with GAT. In normal corneas, the GAT, NCT, and iCare were affected by CCT and CC. The iCare tonometer was less affected by corneal edema than were the NCT and the Tono-Pen. The iCare appears to be a useful device for IOP measurement in eyes with corneal edema after PKP.

Bilateral Ultrathin Descemet's Stripping Automated Endothelial Keratoplasty vs. Bilateral Penetrating Keratoplasty in Fuchs' Dystrophy: Corneal Higher-Order Aberrations, Contrast Sensitivity and Quality of Life.

Background and Objectives: The objective of this paper is to compare the visual outcomes and quality of life (QoL) after bilateral ultrathin Descemet’s stripping automated endothelial keratoplasty (UT-DSAEK) with bilateral penetrating keratoplasty (PK) for Fuchs’ endothelial dystrophy (FED). Materials and Methods: Retrospective comparative cohort study, including 11 patients with FED who underwent bilateral PK and 13 patients with FED who underwent bilateral UT-DSAEK. All patients were already pseudophakic or had undergone a combined cataract procedure. The main outcomes were corrected distance visual acuity (CDVA) corneal higher-order aberrations (HOAs), contrast sensitivity (CS) and quality of life (QoL). Results: The mean follow-up after the second eye surgery was 32.5 ± 10.2 months in PK and 19.6 ± 8.6 months in UT-DSAEK patients. The CDVA in the UT-DSAEK group was significantly better than in the PK one (0.18 ± 0.07 vs. 0.35 ± 0.16 logMAR, p < 0.0001). The mean anterior corneal total HOAs of the central 5 mm were significantly lower in UT-DSAEK eyes than in PK eyes (0.438 ± 0.078 µ and 1.282 ± 0.330 µ respectively, p < 0.0001), whilst the mean posterior total HOAs did not differ between groups (0.196 ± 0.056 µ and 0.231 ± 0.089 µ, respectively, p = 0.253). The CS was lower at 0.75 and 1.5 cycles/degree in P the K group when compared to the DSAEK one (p = 0.008 and 0.005, respectively). The QoL scores by the NEI RQL-42 test exhibited better values in DSAEK patients in 9 out of 13 scales. Conclusion: Our study confirms that UT-DSAEK provides a better visual function in terms of CDVA and CS, together with lower HOAs, when compared to PK. Hence, the vision-related QoL, binocularly evaluated by the NEI RQL-42 items, indicates a higher satisfaction in UT-DSAEK eyes.

Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty in Children and Adolescents With Keratoconus

To compare the outcomes of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) for pediatric keratoconus. Retrospective comparative interventional case series. This study included consecutive pediatric keratoconus cases (≤18 years of age) who received PK (n=45) or DALK (n=54) in 2 different time periods. Postoperative best spectacle-corrected visual acuity (BSCVA), refraction, and complications were compared between the study groups. The mean follow-up was 83.3±46.1 and 63.3±45.6 months in the PK and DALK groups, respectively (P=.10). Postoperatively, BSCVA was 0.20±0.19 logMAR in the PK group and 0.26±0.19 logMAR in the DALK group (P=.11), with a BSCVA of ≥20/40 in 91.1% and 83.3% of eyes, respectively (P=.25). Two groups were comparable regarding postoperative refractive outcomes. Graft epitheliopathy and suture-associated complications were more commonly encountered after DALK, which was attributable to the effect of low-quality grafts on the clinical outcomes of DALK. Ten PK eyes (22.2%) and 9 DALK eyes (16.7%) experienced at least 1 episode of graft rejection within 5 years of corneal transplantation (P=.49). Rejection was reversible in 93.1% and 100% of episodes in the PK and DALK groups, respectively (P=.63). At the postoperative year 5, 95.6% of grafts in the PK group and 98.2% in the DALK group remained clear (P=.45). No significant difference was observed in the outcomes between PK and DALK in pediatric keratoconus. Low-quality donor tissues in DALK increased the incidence of graft epithelial problems and suture-related complications as compared to PK.

Comparison of penetrating keratoplasty and deep anterior lamellar keratoplasty in keratoconus eyes with vernal keratoconjunctivitis.

Purpose:The purpose of the study is to compare outcomes after penetrating keratoplasty (PK) against deep anterior lamellar keratoplasty (DALK) for keratoconus in patients with vernal keratoconjunctivitis (VKC).Methods:Keratoconic patients with VKC who received PK (n = 55, group 1) or DALK (n = 62, group 2) were retrospectively enrolled. The Student’s t test, Mann–Whitney test, Fisher’s exact test, chi-square test, and Kaplan–Meier survival curve were used to compare outcomes between the groups.Results:The follow-up period was 59.4 ± 44.1 and 62.4 ± 38.9 months in groups 1 and 2, respectively (p = 0.70). Postoperative best spectacle-corrected visual acuity was 0.24 ± 0.18 and 0.29 ± 0.19 logMAR, respectively (p = 0.13). Graft rejection occurred in 34.6% and 25.8% of eyes in groups 1 and 2, respectively (p = 0.30). Groups 1 and 2 were comparable in the rates of cataract (3.6% and 12.9%, respectively, p = 0.07) and high intraocular pressure (3.6% and 8.1%, respectively, p = 0.31). Compared with the eyes with inactive VKC, PK eyes that experienced postoperative disease reactivation had a higher rate of suture abscesses (10.9% versus 50.0%, respectively, p = 0.01) and suture-tract vascularization (6.5% versus 33.3%, respectively, p = 0.03). Similarly, disease reactivation significantly increased suture abscesses from 27.3% to 51.7% (p = 0.03) and suture-tract vascularization from 18.2% to 49.6% (p = 0.005) in the DALK group. The graft survival rates were 95.3% in group 1 and 87.9% in group 2 at the 4-year follow-up, with mean durations of 14.4 and 11.1 months, respectively (p = 0.20).Conclusion:The results indicate no difference in outcomes between PK and DALK for keratoconus in patients with VKC. Postoperative VKC reactivation increased the rate of suture-related problems after both techniques of keratoplasty.

Acute corneal edema decades after penetrating keratoplasty for keratoconus in eyes wearing scleral contact lenses

PurposeTo report three cases of acute corneal edema occurring decades after penetrating keratoplasty (PK) for keratoconus in eyes wearing scleral contact lenses (ScCLs) with previously clear corneal grafts. MethodsRetrospective chart review of three ScCL wearers presenting for sudden onset pain and blurred vision. Data extracted included clinical presentation, year and reason for PK, ocular medications and comorbidities, contact lens wearing history, results of any ancillary testing available including corneal topography, anterior segment optical coherence tomography (OCT), and specular microscopy surrounding the event, treatment and outcomes of intervention. The number of PK eyes fit with ScCLs in the author’s practice was determined to estimate the prevalence of this event. ResultsThe three patients each had a longstanding PK for keratoconus performed between 33–35 years prior to presentation and recurrent ectasia. Each patient presented with an acute, painful eye and reduced vision either 3 days, 4 months or 9 years after refitting into ScCLs. Each eye had well demarcated focal microcystic epithelial and stromal edema within the graft and crossing the wound margin onto the host cornea. Although a definitive break or detachment of Descemet’s membrane was not visualized, the presentations suggest these were episodes of acute hydrops. ConclusionsLongstanding PKs with recurrent ectasia and acute focal edema suggestive of corneal hydrops is demonstrated in this case series of ScCL wearers. Although similar events have occurred as part of the natural history of post-PK corneas for keratoconus, the proximity of ScCL refitting to two of the events suggests some association.

The long-term surgical outcomes of conjunctival-limbal autograft procedure with or without penetrating keratoplasty in eyes with unilateral limbal stem cell deficiency.

AIM:The aim of the study is to report the results of conjunctival-limbal autograft (CLAU) transplantation and penetrating keratoplasty (PK) in eyes with limbal stem cell deficiency (LSCD) due to chemical or thermal injury.METHODS:Thirty-one eyes of the 31 patients, who had unilateral LSCD due to chemical or thermal injury, were included in the study. Bilaterally affected cases and LSCD due to Steven-Johnson syndrome and mucous membrane pemphigoid were excluded from the study. All patients underwent a complete ophthalmologic examination. The surgical procedures, postoperative complications, ocular surface status, and visual outcomes were noted.RESULTS:In the CLAU group, regular corneal epithelium and ambulatory vision (≤1.0 logarithm of the minimum angle of resolution [20/200]) were achieved in 81% of eyes, including 22 eyes (71%) that were assessed after a mean follow-up period of 58 months, respectively. The 5-year survival rate of corneal allograft was 33%, 4 ± 13.9 in the CLAU applied eyes. In addition, the corneal graft clarity maintenance rate was found to be higher in patients having ≥12 months duration between CLAU and PK, which is statistically significant (62% vs. 23%, P = 0.046).CONCLUSION:Waiting at least 1 year after CLAU transplantation to perform PK increases corneal clarity. Eyelid problems, even if the eyelids were reconstructed properly, remain a major risk factor for the development of the epithelial disorder in the early and late postoperative period in CLAU applied eyes.

A new technique for fitting of tricurve rigid gas-permeable contact lens in penetrating keratoplasty eyes using Scheimpflug imaging.

Purpose:Rigid gas-permeable (RGP) contact lens fitting after penetrating keratoplasty (PK) is challenging due to significant irregular astigmatism. The aim of the study was to determine a guideline for selecting the initial base curve (BC) of the RGP contact lens fitting in post PK eyes.Methods:The data of patients who had tricurve RGP contact lens fitting post PK were collected retrospectively. The following data were collected: best-corrected visual acuity with glasses and contact lenses; contact lens parameters which included the BC and diameter; corneal topography parameters which included steep keratometry value (K), flat-K, and mean-K; and anterior best fit sphere (BFS) measured using Scheimpflug imaging.Results:The median age of the 40 subjects (46 eyes) who met the inclusion criteria was 37.5 years (IQR 26.7–45.5). The spherical equivalent was –3.00 diopter (D) (–8.31 to –1.56). The median steep-K, flat-K, and mean-K in them were 6.76 mm (6.28–7.07), 7.78 mm (7.37–8.14), and 7.26 mm (6.93–7.46), respectively. The median anterior BFS value of the transplanted cornea was 6.96 mm (6.6–7.37). The median BC of the final RGP lens was 7.0 mm (6.7–7.23) and the median diameter was 9.8 mm (9.4–10.4). Among all the Scheimpflug imaging parameters, the BFS correlated well with the final BC of the RGP contact lens dispensed (R 0.742, P < 0.0001).Conclusion:The anterior corneal surface BFS value can be used as a reference in selecting the initial BC of tricurve RGP contact lens to achieve the best fitting and reducing the chair time of patients after PK.

Anterior best fit sphere–Is it a better starting point to fit rigid gas permeable contact lens in penetrating keratoplasty eyes?–A clinical observation

Purpose: Rigid gas permeable (RGP) contact lens fitting after penetrating keratoplasty (PK) is challenging due to significant irregular astigmatism. The aim of the study was to identify a corneal topography parameter for predicting the initial base curve (BC) of RGP contact lens in post PK eyes.

Risk Factors for Endothelial Decompensation after Penetrating Keratoplasty and Its Novel Therapeutic Strategies.

Purpose To review the risk factors and pathogenesis of endothelial decompensation after penetrating keratoplasty (PKP) and its novel therapeutic strategies. Methods Literature review. Results As the major cause of graft failure in PKP, endothelial decompensation of corneal allograft is considered an irreversible decrease in endothelial cell density and endothelial dysfunction. Various risk factors, including donor status and operative and recipient factors, have been found to be associated with this pathological process. Operative factors like graft size and recipient factors such as indications, glaucoma, or glaucoma surgery history are highly associated with the occurrence of endothelial decompensation, while others are still under investigation. Although the mechanism of these risk factors remains unclear, pathogenesis can be summarized as an acute and chronic loss of endothelium, and cell exchange between donor and recipient is at the core of chronic cell loss. Endothelial keratoplasty has been a useful alternative to repeat standard PKP in eyes with failed grafts. Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK) following failed PKP provide more rapid visual recovery and achieve better rates of graft survival than those of a second PKP. Conclusions Any direct or indirect damage to the endothelium could cause the loss, morphological changes, and dysfunction of endothelial cells. Graft size, indications, and recipient glaucoma or glaucoma surgery history are risk factors for endothelial decompensation. DSAEK and DMEK are novel therapeutic strategies for failed PKP grafts and have potential superiorities compared with repeat PKP.

Outcome of repeat penetrating keratoplasty in eyes with failed penetrating keratoplasty.

Objectives:To report the outcomes of penetrating keratoplasty (PKP) surgeries in eyes with failed PKP.Methods:This was a retrospective, non-comparative, descriptive case series. Thirty eyes of 30 patients with failed PKP comprised our study group, they were reviewed from January 2007 to December 2012 at the King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia. Data were collected on best corrected visual acuity before and after one week, one month, 3 months, 6 months, one year, and 2 years following PKP. Intraoperative and postoperative complications, changes in intraocular pressure (IOP), additional surgical procedure and other ocular comorbidities were also documented. The visual outcomes at 6 months and one year were associated with risk factors.Results:Before intervention, 18 (60%) eyes had vision <20/400. Vision was 20/20 to 20/60 in 10 (30%) eyes at 6 months, 17 (57%) eyes at 12 months, and 22 (73%) eyes at 24 months. The variation in IOP at different follow up periods was not significant (p=0.2). The presence of other ocular comorbidity was not significantly associated with functional visual outcome (p=0.4). Additional surgical procedure after repeat PKP enabled a regain of excellent vision in 9 (47%) eyes at one year. The numbers for past corneal surgeries were significantly associated with the visual outcome at 6 months.Conclusion:Penetrating keratoplasty to manage failed PKP resulted in reducing visual disabilities.

Five-Year Graft Survival Comparing Descemet Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty

To compare 5-year graft survival after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) in Asian eyes. Prospective, nested, cohort study. Consecutive patients who underwent DSAEK (423 eyes) or PK (405 eyes) for Fuchs' endothelial dystrophy (FED) or bullous keratopathy (BK). Clinical data and donor and recipient characteristics were recorded from our prospective cohort from the Singapore Corneal Transplant Registry. All surgeries were performed by the corneal surgeons at our center, which included cases performed or partially performed by corneal fellows in training under direct supervision. Five-year cumulative graft survival. Overall mean age was 67.8±9.8 years, and 50.1% of patients were men. There were no significant differences in age (P= 0.261) or gender (P= 0.78) between PK and DSAEK groups in our predominantly Chinese (76.6%) Asian cohort, with more BK compared with FED (68.1% vs. 31.9%; P<0.001). Overall 5-year graft survival was superior for DSAEK compared with PK (79.4% vs. 66.5%; P < 0.001, log-rank test). Median 5-year percent endothelial cell density loss was significantly greater in PK compared with DSAEK (60.9% vs. 48.7%; P=0.007). Cox regression analysis revealed that BK was a significant factor associated with graft failure (hazard ratio [HR], 3.30; 95% confidence interval [CI], 2.05-5.33; P < 0.001), and PK was more likely to fail compared with endothelial keratoplasty (HR, 1.61; 95% CI, 1.08-2.41; P= 0.02) adjusting for confounders such as recipient age, gender, and donor factors. Five-year cumulative incidence of complications such as graft rejection (P<0.001), epitheliopathy (P < 0.001), suture-related corneal infections (P < 0.001), and wound dehiscence (P=0.002) were greater in the PK group compared with the DSAEK group. In Asian eyes from the same study cohort with standardized surgical and postoperative regimes, 5-year graft survival was superior for DSAEK compared with PK in eyes with FED and BK.