A surgical alternative of fusiform penetrating keratoplasty for the management of severe infectious keratitis

AIM:To describe the surgical procedure of fusiform penetrating keratoplasty(FPK)using multiple trephines of different sizes for treating patients with severe infectious keratitis.METHODS:Fourteen eyes underwent FPK,and 15 eyes received conventional penetrating keratoplasty(PK)were included in the study.The best-corrected visual acuity(BCVA),refractive outcomes,endothelial cell density,and postoperative complications were recorded.RESULTS:The FPK group was followed for an average of 15.3±2.1mo,whereas the PK group was followed for 16.1±1.9mo.The corneal ulcers were elliptical-shaped in all 14 eyes in the FPK group.The mean BCVA(logMAR,0.26±0.13)showed no statistically significant differences from that in the PK group(logMAR,0.21±0.12,P>0.05)at 1y after surgery.But the mean curvature,mean astigmatism,and mean spherical equivalent in the FPK group were lower than those in the PK group(P<0.05).Peripheral anterior synechia was observed in one patient in the FPK group,whereas 6 patients in the PK group.Suture loosening and neovascularization were observed in 4 and 5 eyes in the PK group,respectively.No graft immune rejection or elevation of intraocular pressure was observed in the two groups.CONCLUSION:For patients with elliptical-shaped corneas or corneal ulcers,FPK can avoid disrupting of corneal limbus,reduce the risk of postoperative complications,and can result in satisfactory visual quality.

Trends in the indications for penetrating keratoplasty in Shandong,2005-2010

AIM: To identify the current indications and the trend shifts for penetrating keraboplasty (PKP) in Shandong. METHODS: The medical charts of all patients who underwent PKP at Shandong Eye Institute from June 1, 2005 to May 31, 2010 were analysed retrospectively. RESULTS: A total of 875 patients (875 eyes) received PKP in this 5-year period, accounting for 61.6% of all corneal transplantation surgeries. The leading indications for PKP were infectious keratitis (37.1%), HSK (19.1%), keratoconus (11.2%), bullous keratopathy (8.5%), regrafting (6.7%) and corneal scarring (4.8%). The percentage of PKP for keratoconus declined year by year, whereas the percentage of bullous keratopathy had a mild annual increase. Fungal infections accounted for 65.2% of the infectious keratitis cases, remaining the leading cause of corneal infection. In addition, 54.1% of bullous keratopathy cases were associated with cataract surgery. The leading initial diagnoses associated with regrafting were infectious keratitis (38.9%), HSK (18.6%) and corneal burn (16.9%). The major causes of regrafting included graft endothelial dysfunction (39.0%), graft ulcer (28.8%) and primary disease recurrence (15.3%). CONCLUSION: Infectious keratitis remained the leading indication for PKP in Shandong, and fungal infections were still the major cause of corneal infections. There was an increasing trend in the percentage of PKP cases indicated for bullous keratopathy but a decline in the same for keratoconus. Even with a decline in the overall proportion among all corneal transplantation surgeries, PKP is still the major corneal transplant choice in Shandong.

Long-term outcomes of penetrating keratoplasty in keratoconus: analysis of the factors associated with final visual acuities

AIM:To investigate the long-term results of penetrating keratoplasty(PK)in patients with keratoconus(KC)and to evaluate factors that might influence the final visual outcome.METHODS:We retrospectively reviewed the data of all patients with clinical KC who had undergone PK by a single corneal surgeon in a single center from May 1980to December 2005.The age of the patients,preoperative best-corrected visual acuity(BCVA),corneal thickness,death to preservation time,and preservation to transplantation time were recorded.Additionally,postoperative complications such as graft rejection,development of glaucoma and specular microscopy were checked during the follow-up.RESULTS:Sixty-nineeyesfrom69patientswerefinally included.The follow-up period was 8.64±6.13y.Graft rejection occurred in 4 eyes of 69 cases(5.8%),and the time to graft rejection was 2.1±1.3y.A Kaplan-Meier survival analysis showed that the estimated cumulative probability of graft rejection at 6,13,and 17y after PK were 95.6%,90.0%,and 78.8%,respectively.When we evaluated factors that might influence final BCVA in eyes,no disparity donor-host trephine size(same graft size)as well as higher spherical equivalent,and average Kvalue were associated with higher final BCVA.(P=0.006,0.051,0.092,and 0.021 in eyes with follow-up【8y;P=0.068,0.065,and 0.030 in eyes with follow-up≥8y,respectively).CONCLUSION:The long-term results of PK in patients with KC were favorable with a high percentage of good BCVA.Less myopic change and low average K-reading,as well as a surgical technique using the same size donor-recipient button may provide better visual outcomes particularly in patients with KC.

Comparison of visual and topographic outcomes of deep-anterior lamellar keratoplasty and penetrating keratoplasty in keratoconus

AIM：To compare visual,surgical and topographic outcomes of deep anterior lamellar keratoplasty（DALK）and penetrating keratoplasty（PK）for keratoconus（KC）.METHODS：In this multicenter,prospective,randomized clinical trial 76 eyes of 71 KC patients operated between January 2011 and July 2014 in 2 tertiary referral hospitals were included. Consecutive patients were alternately selected to receive one of the two surgical methods. Thirty eight eyes underwent DALK with the big-bubble technique and 38 eyes underwent PK.RESULTS：Mean best spectacle corrected visual acuity（BSCVA）at the first postoperative week（P=0.012）and the first postoperative month（P〈0.001）was statistically significantly higher in DALK group. The mean BSCVA at12 mo was not significantly different for DALK（0.30±1.99 log MAR）versus PK（0.40±0.33 log MAR）（P=0.104）. The76.3% of the eyes had a BSCVA over 0.5 in DALK and 47.4%in PK group（P=0.009）. The 7.9% of the eyes had a BSCVA of 1.0 in DALK and 5.3% in PK group（P=0.644）. Mean spherical equivalent was-2.94 D in DALK and-3.09 D in PK group.Mean topographic astigmatism was 4.62 D and 4.18 D respectively. Regular topographic patterns were observed in 31（81.6%）of DALK and 29（76.3%）of PK（P=0.574）. The most frequent topographic pattern was oblate asymmetric bow tie,seen in 39.5% in DALK and 23.7% in PK. CONCLUSION：Big bubble DALK provides an earlier visual improvement compare to PK. However,visual and topographic outcomes are similar to those in PK at 1y. Postoperative complications including rejection and intraocular pressure elevation are more frequent in PK. DALK is a safer alternative to PK for KC. However,intraoperativeperforation of the Descemet＇s membrane is a significant complication.

Spontaneous wound dehiscence after penetrating keratoplasty

Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-yearold Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty(PKP) which was performed three years ago. An Ahmed glaucoma valve(New World Medical, Ranchos Cucamonga, CA) was inserted ten months after the third PKP, which successfully controlled intraocular pressure(IOP). At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1%(Sina Darou, Tehran, Iran)with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 o`clock associated with anterior wound gape and severe corneal edema.Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field.

Changes in endothelial cell density following penetrating keratoplasty and deep anterior lamellar keratoplasty

· AIM: To compare the corneal endothelial cell density (ECD) of clear grafts after penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). · METHODS: The study included 44 and 54 patients treated with PK and DALK, respectively, between March 2006 and April 2010. Corneal ECD was examined using specular microscopy at postoperative 1, 3, 6, 12, and 18 months, and the values were compared. · RESULTS: Corneal ECD reduction in the PK group was 7.4%, 15.2%, 23.5%, and 28.9% at 3, 6, 12 and 18 months respectively after surgery, compared with 4.2 % in the first month (P <0.01). These figures were 3.0%, 6.7%, 7.2%, and 7.7% at 3, 6, 12 and 18 months respectively, compared with 2.2 % in the first month in the DALK group (P >0.05). · CONCLUSION: Compared with DALK,PK significantly reduced ECD of the clear grafts. These results suggest that survival of endothelial cells in grafts is better after DALK than after PK. ·

Graft survival and visual outcome after simultaneous penetrating keratoplasty and cataract extraction

AIM: To evaluate the indications, complications, and visual and graft survival outcomes in eyes that had undergone simultaneous cataract extraction and penetrating keratoplasty (PKP). ·METHODS: We described a retrospective study of 101 patients who had undergone simultaneous cataract extraction and PKP at King Khaled Eye Specialist Hospital between January 1, 2001, and December 31, 2002. All patients were followed up postoperatively with maximum follow-up 68 months. ·RESULTS: The mean age of patients was 61 years. The mean overall follow -up was 27 months. The most common indications for surgery were corneal scarring (45.5% ), previous failed graft (15.8% ), corneal ulcer (12.9% ), Fuchs endothelial dystrophy (8.9% ), stromal dystrophy (2.9% ), and other conditions (14.5% ). Overall, 69 grafts (68.3% ) remained clear at final follow -up. Previous glaucoma or postoperative glaucoma had no statistically significant effects on graft outcome (P 】0.05). The graft rejection rate (17.8% ) was a significant risk factor for failure (P =0.00). Age, gender, indications for surgery, corneal graft diameter, and intraoperative vitreous loss had no statistically significant effects on the PKP outcome (P 】0.05). Postoperative visual acuity was significantly associated with preoperative visual acuity (P 【0.01). ·CONCLUSION: The present study provides evidence that performing a combined procedure results in more rapid visual rehabilitation and good graft clarity.

Changing trends in penetrating keratoplasty indications at a tertiary eye care center in Budapest,Hungary between 2006 and 2017

AIM:To analyze the changing trends in penetrating keratoplasty(PKP)indications.METHODS:This retrospective study included all patients with PKP between 2006 and 2017.Patients were classified using histological diagnoses.Our groups were as the following:pseudophakic or aphakic bullous keratopathy,regraft,acute necrotizing and ulcerative keratitis,keratoconus,Fuchs'dystrophy,corneal dystrophy other than Fuchs',corneal scar,other diagnoses and failed endothelial keratoplasty graft.Additionally,two different time-periods(2006-2012 and 2013-2017)were analysed.RESULTS:Totally 1721 histological analyses of 1214 patients were available for review.The diagnoses were pseudophakic or aphakic bullous keratopathy in 487(28.3%),regraft in 443(25.7%),acute necrotizing and ulcerative keratitis in 313(18.2%),corneal scar in 153(8.9%),keratoconus in 140(8.1%).Fuchs'dystrophy in 61(3.5%),corneal dystrophy other than Fuchs'in 46(2.7%),other diagnoses in 44(2.6%)and failed endothelial keratoplasty graft in 34(2.0%)cases.From the first to the second analysed time-period,incidence of acute necrotizing and ulcerative keratitis,corneal scar,Fuchs'dystrophy increased(P<0.032 for all)and incidence of keratoconus significantly decreased(P=0.015).CONCLUSION:Pseudophakic or aphakic bullous keratopathy is the leading indication for PKP,followed by regraft and acute necrotizing and ulcerative keratitis.

Indications for penetrating keratoplasty and anterior lamellar keratoplasty during 2010-2017

AIM: To review the indications of penetrating keratoplasty(PK) and anterior lamellar keratoplasty(ALK) at Qingdao Eye Hospital, Shandong Eye Institute, Qingdao, China, from 2010 to 2017. METHODS: The data of all patients undergoing PK or ALK from January 2010 to December 2017 was retrospectively reviewed, with the indications during 2010-2013 and 2014-2017 compared. RESULTS: A total of 1869 eyes were included, among which 1405 eyes(75.2%) had PK and 464 eyes(24.8%) had ALK. The leading indications were suppurative keratitis(36.8%), keratoconus(15.5%), herpes keratitis(13.1%), and regraft(10.5%). In eyes undergoing PK, the top four indications were suppurative keratitis(38.7%), herpes keratitis(15.3%), keratoconus(12.6%), and regraft(12.5%) during 2014-2017, with the proportion of suppurative keratitis and herpes keratitis decreased while regraft and keratoconus increased compared with 2010-2013. In eyes with ALK, suppurative keratitis(30.8%), keratoconus(24.1%), corneal dystrophies and degenerations(10.6%), and corneal dermoid tumor(9.7%) were the top four indications, and there was no significant difference for the proportion of each indication between 2010-2013 and 2014-2017. CONCLUSION: Suppurative keratitis is the most common indication for PK and ALK at Qingdao Eye Hospital during 2010-2017, followed by keratoconus, herpes keratitis, and regraft. In eyes treated with PK, the proportion of suppurative keratitis and herpes keratitis decrease while regraft and keratoconus increase during 2014-2017 compared with 2010-2013.

Safety of prophylactic intracameral moxifloxacin ophthalmic solution after cataract surgery in patients with penetrating keratoplasty

AIM:To determine the safety of prophylactic intracameral moxifloxacin after cataract surgery in patients with penetrating keratoplasty(PKP).METHODS:In this retrospective study of consecutive patients who had phacoemulsification cataract surgery after PKP, were treated with intracameral moxifloxacin0.5% ophthalmic solution(0.5 mg/0.1 mL). The main outcome measures were anterior chamber reaction, best corrected visual acuity(BCVA), corneal endothelial cell count(ECC), and central corneal thickness(CCT).RESULTS:Fifty-five patients were recruited(26 males,29 females). The mean age was 54.36±4.97y(range 45-64y).All eyes had improved postoperative BCVA. The mean BCVA was 0.25 preoperatively and 0.57 postoperatively,which was statistically significant(P 【0.001). One eye had 3+, 7 eyes had 2+, 12 eyes had 1+ and 8 eyes had trace amount of aqueous cells on the first day after surgery. All eyes had no anterior chamber cells at subsequent follow up examinations. Effective phacoemulsification time was 4.33 ±1.01 s. The mean ECC was 2340.20 cells/mm2 preoperatively and 1948.75 cells/mm21 mo postoperatively(P 【0.001). The increase of21.09 μm in postoperative pachymetry 1mo after surgery was statistically significant(P 【0.001).CONCLUSION:Nountowardeffectswereobservedafter intracameral injection of moxifloxacin(0.5 mg/0.1 mL) in terms of anterior chamber reaction, CCT, ECC, and visual rehabilitation at the conclusion of cataract surgery in patients with PKP.

Black diaphragm intraocular lens implantation and penetrating keratoplasty in aphakic eyes with traumatic aniridia

AIM:To evaluate the long-term outcome of implantation of black diaphragm intraocular (BDI) lens combined with penetrating keratoplasty (PKP) for managing aphakic eyes with traumatic aniridia and corneal damage. METHODS: Six aphakic eyes of six patients with traumatic aniridia and corneal damage had BDI lens implantation at Qingdao Eye Hospital, Shandong Eye Institute from June 2008 to November 2011. Medical records of the patients were reviewed. Three patients received PKP and after 12-18months were implanted with BDI lens. The other three patients completed PKP and BDI lens implantation at the same time. The corrected visual acuity, intraocular pressure and number of corneal endothelial cells were monitored. RESULTS: The patients were followed up for an average of 24.3 ±12.1months (range 14-48 months). All BDI lenses were located well. The best corrected visual acuity got improved in 5 patients (0.1-1.0) and decreased in 1 patient from 0.4 to 0.2. Three patients had normal intraocular pressure (IOP) after implantation. Two patients required antiglaucoma medications to control IOP within the normal range and 1 patient implanted Ahmed glaucoma valve to control IOP. The corneal grafts kept transparent in all eyes and the corneal endothelial counting 】1 000/mm2 , although two patients experienced acute graft rejection and loss more than 30% corneal endothelial cells.CONCLUSION: Implantation of BDI lens combined with PKP is an effective option for managing aphakic eyes with traumatic aniridia and corneal damage. Although the results in our study are encouraging, additional studies of the long -term safety and efficacy are required. Alarger study population and longer follow-up may be beneficial.

Effects of immunosuppressants after penetrating keratoplasty:meta-analysis of randomized controlled trials

AIM: To assess the effectiveness of immunosuppressants in the prophylaxis of corneal allograft rejection after high-risk keratoplasty and normal-risk keratoplasty. METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CNKI, VIP and reference lists of articles. Date of most recent search: 18 June, 2011. All randomised controlled trials (RCTs) assessing the use of immunosupressants in the prevention of graft rejection, irrespective of publication language. Two authors assessed trial quality and extracted data independently. Only dichotomous outcomes (clear graft survival, ratio of immune reactions and side effects) were available and were expressed as relative risk (RR) and 95% confidence intervals (CI). RESULTS: Seven studies were included in this review. In the comparing of mycophenolate mofetil (MMF) with placebo, the results showed MMF could significantly reduce immune reactions compared with placebo (RR 1.08 95% Cl 0.95 to 1.21), but no effect on clear graft survival (RR 1.11 95% Cl 0.90 to 1.35). In clear graft survival and immune reactions, MMF and cyclosporine A (CsA) showed similar effect (RR 1.11 95% Cl 0.90 to 1.35, and RR 1.48, 95% Cl 0.56 to 3.93, respectively). Tacrolimus (FK506) and steroid showed similar effects on clear graft survival and immune reactions (RR 0.32, 95% CI 0.02 to 6.21, and RR 1.00, 95%CI 0.88 to 1.14, respectively). No drug relative side effect has been found. CONCLUSION: MMF may reduce immune reactions in both normal-risk and high-risk rejection of penetrating keratoplasty. CsA and FK506 showed similar effects as MMF. However, due to the lack of large clinical trials, the evidence remain weak, the quality of evidences were rated as very low to moderate. Large, properly randomised, placebo-controlled, double masked trials are needed to evaluate the effect of immunosuppressants.

Penetrating keratoplasty in children under 3 years old with congenital corneal opacities

AIM:To evaluate the graft rejection and visual outcomes after penetrating keratoplasty(PK)in the presence of various congenital corneal opacities in children.METHODS:In this retrospective cohort study,children who underwent PK were then followed for 5 y.The patient’s medical records were collected from June 2014 until June 2019 and analyzed in December 2019.All patients were children under three years old with congenital corneal opacities with or without microcornea who came to a pediatric ophthalmologist and underwent PK in Jakarta Eye Center(JEC).Beforehand,all children have participated in a thorough evaluation for PK.In the case of severe microcornea was not advised to undergo surgery.The visual outcomes and graft survival rate were described in percentages.The graft survival plot was presented with Kaplan-Meier,while the visual acuity was analyzed using the Wilcoxon signed ranks test.RESULTS:Sixteen eyes from eleven patients(seven girls and four boys)underwent PK.The graft survival rate of the first 6,12,and 18 mo later of keratoplasty was 100%,83.3%,and 66.7%,respectively.The overall mean survival time is 22 mo(standard error 2.419),and no significant difference between the patients underwent PK before and after 36 mo of their age(P=0.52).The graft failure was 50%,and postsurgery complications included cataract 43.7%,band keratopathy 12.5%,and scleromalasia 6.25%.Wilcoxon test analysis of visual acuity post keratoplasty was not statistically significant(P=0.34),while overall showed 44%improvements of visual outcome for 5 y of follow-up.With a good survival at one year up to 22 mo(83.3%),the visual acuity could be achieved(63%),and showed improvements(44%)during follow-up.CONCLUSION:The complications are frequent for pediatric PK.Thus,corneal surgery on infants requires careful case selection,adequate pre-operative evaluation,skilled surgery(optical correction),very close cooperation family–physician,intensive post-operation care,and amblyopia management in the future.

Midterm outcomes of penetrating keratoplasty following allogeneic cultivated limbal epithelial transplantation in patients with bilateral limbal stem cell deficiency

AIM:To evaluate the midterm outcomes of penetrating keratoplasty(PK)following allogeneic cultivated limbal epithelial transplantation(CLET)for bilateral total limbal stem cell deficiency(LSCD).METHODS:Ten patients(10 eyes)with bilateral LSCD were enrolled in this prospective noncomparative case series study.Each participant underwent PK approximately 6 mo after a CLET.Topical tacrolimus,topical and systemic steroids,and oral ciclosporin were administered postoperatively.Best-corrected visual acuity(BCVA),intraocular pressure(IOP),ocular surface grading scores(OSS),corneal graft epithelial rehabilitation,persistent epithelial defect(PED),immunological rejection,and graft survival rate were assessed.RESULTS:The time interval between PK and allogeneic CLET was 6.90±1.29(6-10)mo.BCVA improved from 2.46±0.32 log MAR preoperatively to 0.77±0.55 log MAR post-PK(P<0.001).Kaplan-Meier analysis of mean graft survival revealed graft survival rates of 100%at 12 and 24 mo and 80.0%at 36 mo.PEDs appeared in 5 eyes at different periods post-PK,and graft rejection occurred in 4 eyes.The total OSS decreased from 12.4±4.4 before allogeneic CLET to 1.4±1.51 after PK.CONCLUSION:A sequential therapy design of PK following allogeneic CLET can maintain a stable ocular surface with improved BCVA despite the relatively high graft rejection rate.

General anesthesia versus local anesthesia for penetrating keratoplasty: a prospective study

AIM:To examine which anesthesia general or local is more effective for penetrating keratoplasty(PKP).METHODS:Patients with indications for PKP(n=141)were enrolled in a prospective study and randomly divided into general anesthesia group(group A,70 eyes)and local anesthesia group(group B,71 eyes).Patients received optical PKP(group A1,30 eyes;group B1,30eyes)or therapeutic PKP(group A2,40 eyes;group B2,41 eyes).Measurement of anterior chamber treatment time(T)for PKP patients and the ratio(R)of the area of the pupils to that of recipient graft region.T and R values,as well as perioperative and postoperative complications,were compared between groups A and B using t-test orχ2test.RESULTS:Patients were followed for 2wk after PKP.T was(13.45±8.64)min for group A and(7.36±5.24)min for group B,a statistically significant difference(P【0.001).The R value for group A was stable during the operation,while for PKP patients in group B the value initially increased then gradually decreased to normal after suturing.In group B,extrusion of intraocular contents occurred in 5 eyes,and iridal prolapse occured in 11cases;no perioperative complications occurred in group A.Relapse rate for fungal keratitis was 13.04%in group B and 0%in group A.CONCLUSION:Under general anesthesia,pupils remaine stable during PKP and perioperative complications are averted.General anesthesia gives more time to treat pathological changes in the anterior chamber and treatment success rate is higher.

Penetrating keratoplasty in monocular patients

I am Dr. Baran Kandemir, from Opthalmology Department of Dr. Ltitfi Kirdar Kartal Research and Training Hospital, Istanbul, Turkey. 1 write to present outcomes of penetrating keratoplasty （PK） in monocular patients. Bilateral visual impairment has important impacts on health-related quality of life and its physical and psychological consequences are proposed to be comparable to other important chronic medical illnesses . Therefore in monocular patients, an unsuccessful surgical intervention that might lead to permanent visual loss would have some negative reflections on life quality of the patient.

Weighing of risk factors for penetrating keratoplasty graft failure：application of Risk Score System

AIM：To analyze the relationship between the score obtained in the Risk Score System（RSS）proposed by Hicks et al with penetrating keratoplasty（PKP）graft failure at 1y postoperatively and among each factor in the RSS with the risk of PKP graft failure using univariate and multivariate analysis.METHODS：The retrospective cohort study had 152 PKPs from 152 patients. Eighteen cases were excluded from our study due to primary failure（10 cases）,incomplete medical notes（5 cases）and follow-up less than 1y（3cases）. We included 134 PKPs from 134 patients stratified by preoperative risk score. Spearman coefficient was calculated for the relationship between the score obtained and risk of failure at 1y. Univariate and multivariate analysis were calculated for the impact of every single risk factor included in the RSS over graft failure at 1y. RESULTS：Spearman coefficient showed statistically significant correlation between the score in the RSS and graft failure（P〈0.05）. Multivariate logistic regression analysis showed no statistically significant relationship（P〉0.05）between diagnosis and lens status with graft failure. The relationship between the other risk factors studied and graft failure was significant（P〈0.05）,although the results for previous grafts and graft failure was unreliable. None of our patients had previous blood transfusion,thus,it had no impact. CONCLUSION：After the application of multivariate analysis techniques,some risk factors do not show the expected impact over graft failure at 1y.

Donor cornea quality used for penetrating keratoplasty vs deep anterior lamellar keratoplasty

Deep anterior lamellar keratoplasty(DALK) has recently been introduced as an alternative procedure to penetrating keratoplasty(PK) for corneal pathologies not affecting the corneal endothelium. DALK does not rely on donor endothelium and requires less rigid criteria for donor corneal tissue quality. Therefore, DALK makes it possible to use donor corneas deemed unsuitable for PK. Furthermore, lamellar keratoplasty allows acellular corneal tissue to be transplanted. As a result, long-term preservation techniques are being revisited to increase the availability of donor corneas and subsequently alleviate constraints of availability, cost, storage, and transportation in many countries. The recent alterations in corneal transplantation techniques and hence the type of donor cornea tissues used for each technique, may require corneal surgeons and eye banks to reevaluate their selection criteria. The purpose of this systematic review is to present an updated analysis on the type and quality of donor corneas used for PK and DALK, assess the influence of donor and eye bank factors on the quality of donor corneas, and determine whether any of these donor factors affect clinical outcomes, complications, and graft survivals.

Large Penetrating Keratoplasty in the Management of Keratoglobus: A Case Report

Background: Keratoglobus is a rare noninflammatory corneal disorder characterized by diffuse corneal thinning and globular protrusion of the cornea. Surgical management of keratoglobus is challenging and the standard method has not yet been defined. Aim: To present the role of large penetrating keratoplasty (PK) in the management of keratoglobus. Case Presentation: A 29-year-old male patient with bilateral keratoglobus presented with acute corneal hydrops in his right eye following extensive Descemet’s membrane rupture, with a visual acuity in this eye limited to hand movement. Peripheral cornea was extremely thin and blue sclera was present. Acute hydrops was managed conservatively at this stage and two months later large PK was performed in the right eye using 9.5 mm diameter graft over a 9 mm patient’s cornea trephination. Minor aqueous leakage was seen on the first postoperative day, managed with 2 more interrupted 10.0 nylon sutures. No further complications were noticed and postoperative course was uneventful. Fifteen months postoperatively the graft was clear and best corrected visual acuity was 20/60. Conclusions: Large penetrating keratoplasty has an important role in the management of keratoglobus, in cases where peripheral tuck-in lamellar keratoplasty or epikeratoplasty present serious intraoperative difficulties in host lamellar dissection and in stabilizing the graft due to extensive peripheral corneal and scleral thinning.

Elimination of Post-Operative Complications in Penetrating Keratoplasty by Deploying Six Sigma

This paper shows how a public eye and research hospital in Turkey initiated Six Sigma principles to reduce the number of complications occurring after penetrating keratoplasty surgeries. Data were collected for nine years. To analyse the complications among 55 patients (59 eyes) underwent penetrative keratoplasty, main tools of Six Sigma’s Define-Measure-Analyze-Improve-Control (DMAIC) improvement cycle such as SIPOC table and Failure, Mode and Effect Analysis (FMEA) were implemented. Sources and root causes of eleven types of complications were identified and reported. For a successful penetrating keratoplasty surgery patient’s anatomy, suitability of donor cornea, experience of ophthalmic surgeon, sterilization and hygiene, and performance of the equipment were determined to be the “critical-to-quality” factors. The complication with the highest hazard score was found to be the glaucoma. The process sigma level of the process was measured to be 3.1418. The surgical team concluded that all types of post-operative complications should be significantly reduced by taking the necessary preventive measures.