Comparison of therapeutic effects between big-bubble deep anterior lamellar keratoplasty and penetrating keratoplasty for medically unresponsive Acanthamoeba keratitis
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SUBMITTER: Qi X
PROVIDER: S-EPMC10910827 | biostudies-literature | 2024 Jan
REPOSITORIES: biostudies-literature
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Project description:Acanthamoeba keratitis (AK) is an intractable infection of the cornea. Penetrating keratoplasty is widely used for the management of severe AK but suffers from complications like graft rejection, endophthalmitis, and glaucoma. Herein, we aimed to describe the surgical technique and the results of elliptical deep anterior lamellar keratoplasty (eDALK) for the management of severe AK. In this retrospective case series, records of consecutive patients with AK poorly responsive to medical treatment who underwent eDALK from January 2012 to May 2020 were reviewed. The largest diameter of infiltration was ≥8 mm and did not involve the endothelium. The recipient bed was made by an elliptical trephine, and big bubble or wet-peeling technique was performed. Postoperative best spectacle-corrected visual acuity, endothelial cell density, corneal topographic data, and complications were evaluated. Thirteen eyes of thirteen patients (eight men and five women, 45.54 ± 11.78 years old) were included in this study. The mean follow-up interval was 21.31 ± 19.59 months (range, 12-82 months). At the last follow-up, the mean best spectacle-corrected visual acuity was 0.35 ± 0.27 logarithm of the minimum angle of resolution. The mean refractive and topographic astigmatism were - 3.21 ± 1.77 and 3.08 ± 1.14 D, respectively. Intraoperative perforation was encountered in one case and double anterior chambers occurred in two cases. One graft developed stromal rejection and one eye developed amoebic recurrence. eDALK can serve as the first-line surgical management of severe AK poorly responsive to medical treatment.
| S-EPMC10229934 | biostudies-literature
Project description:Deep anterior lamellar keratoplasty (DALK) is a highly challenging procedure for cornea transplant that involves removing the corneal layers above Descemet's membrane (DM). This is achieved by a "big bubble" technique where a needle is inserted into the stroma of the cornea down to DM and the injection of either air or liquid. DALK has important advantages over penetrating keratoplasty (PK) including lower rejection rate, less endothelial cell loss, and increased graft survival. In this paper, we successfully designed and evaluated the optical coherence tomography (OCT) distal sensor integrated needle for a precise big bubble technique. We successfully used this sensor for micro-control of a robotic DALK device termed AUTO-DALK for autonomous big bubble needle insertion. The OCT distal sensor was integrated inside a 25-gauge needle, which was used for pneumo-dissection. The AUTO-DALK device is built on a manual trephine platform which includes a vacuum ring to fix the device on the eye and add a needle driver at an angle of 60 degrees from vertical. During the test on five porcine eyes with a target depth of 90%, the measured insertion depth as a percentage of cornea thickness for the AUTO-DALK device was 90 . 05 % ± 2 . 33 % without any perforation compared to 79 . 16 % ± 5 . 68 % for unassisted free-hand insertion and 86 . 20 % ± 5 . 31 % for assisted free-hand insertion. The result showed a higher precision and consistency of the needle placement with AUTO-DALK, which could lead to better visual outcomes and fewer complications.
| S-EPMC7013995 | biostudies-literature
Project description: Not available
| S-EPMC10714035 | biostudies-literature
Project description:PURPOSE:To examine big-bubble (BB) formation success rates in deep anterior lamellar keratoplasty (DALK) at various corneal depths using real-time guidance from swept-source, microscope-integrated optical coherence tomography (SS-MIOCT). METHODS:The DALK procedure was performed ex vivo with 34 human donor corneoscleral buttons on pressurized artificial anterior chambers using the BB technique employed by Anwar and Teichmann. We inserted a needle under controlled ex vivo conditions to corneal depths ranging from 40% to ?90% using real-time guidance from SS-MIOCT and injected air. BB success was then determined for each injection. RESULTS:The average needle depth for successful full BB formation was 79.9% ± 3.0% compared with 66.9% ± 2.6% for partial BB formation and 49.9% ± 3.4% for no BB formation (P < 0.0001). Expressed as stroma below the needle tip, this corresponded to 123.9 ± 20.0 ?m for successful full BB formation compared with 233.7 ± 23.8 ?m for partial BB formation and 316.7 ± 17.3 ?m for no BB formation (P < 0.0001). All other variables tested (sex, race, age, endothelial cell density, air injected, needle angle, and central corneal thickness) did not significantly affect BB formation success rates. CONCLUSIONS:BB formation in DALK is more successful if needle insertion and air injection occur at deeper corneal depth. However, ?90% corneal depth was not necessary in this ex vivo model of DALK. SS-MIOCT can be used to accurately guide the needle in real time.
| S-EPMC5067966 | biostudies-literature
Project description: Not available
| S-EPMC6043615 | biostudies-literature
Project description:PurposeTo develop and perform ex vivo testing for a device designed for semiquantitative determination of intracorneal dissection depth during big bubble (BB) deep anterior lamellar keratoplasty.MethodsA prototype device connected to a syringe and cannula was designed to determine depth of intrastromal placement based on air rebound pressure emitted by a software controlled generator. Ex vivo testing of the device was conducted on human corneas mounted on an artificial anterior chamber in three experiments: (1) cannula purposely introduced at different depths measured with anterior segment optical coherence tomography, (2) cannula introduced as per the BB technique, and (3) simulation of the BB technique guided by the device.ResultsA positive pressure differential and successful BB were observed only when the cannula was positioned within 150 microns from the endothelial plane. In all successful BB cases (21/40), a repeatable increase in tissue rebound pressure was detected, which was not recorded in unsuccessful cases. The device was able to signal to the surgeon correct placement of the cannula (successful BB) in 16 of 17 cases and incorrect placement of the cannula (unsuccessful BB) in 8 of 8 cases (94.1% sensitivity, 100% specificity).ConclusionsIn our ex vivo model, this novel medical device could reliably signal cannula positioning in the deep stroma for effective pneumatic dissection and possibly aid technical execution of BB deep anterior lamellar keratoplasty.Translational relevanceA medical device that standardizes big bubble deep anterior lamellar keratoplasty could increase the overall success rate of the surgical procedure and aid popularization of deep anterior lamellar keratoplasty.
| S-EPMC9804022 | biostudies-literature
Project description:PurposeTo present a case of hematocornea occurring in a post-penetrating keratoplasty (PK) eye and to report the outcomes of deep anterior lamellar keratoplasty (DALK) performed by simple stromal peeling.ObservationsA 45-year-old female presented with hematocornea in the left eye that previously underwent PK 26 months prior for keratoconus. Clinical examination revealed a dense reddish-brown opacity within the PK graft which was associated with deep corneal neovascularization. Over 6 months, intracorneal hemorrhage developed a rust-colored appearance with minimal clearing. DALK was performed using the stromal peeling technique for post-PK eyes. Briefly, a dense partially organized hemorrhage was identified at the natural plane of separation, as confirmed by ex vivo histologic examination; after peeling of the deep corneal stroma and evacuation of the intracorneal hemorrhage, the residual bed appeared akin to pre-Descemet's layer-Descemet membrane-endothelium complex. One year after DALK, the graft remained clear with ECD of 1034 cells/mm2.Conclusions and importanceIntracorneal hemorrhage is a rare but potentially sight-threatening complication following PK. Using the stromal peeling technique, DALK can be attempted to preserve functional endothelium in post-PK eyes. In the presence of a dense intracorneal hemorrhage, the spread of erythrocytic debris within the stroma can guide deep lamellar cleavage.
| S-EPMC9883201 | biostudies-literature
Project description:PurposeTo evaluate difference in therapeutic outcomes between deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP) for the clinical treatment of keratoconus.MethodsA comprehensive search was conducted in Pubmed, EMBASE, Cochrane Library, and Web of science. Eligible studies should include at least one of the following factors: best corrected visual acuity (BCVA), postoperative spherical equivalent (SE), postoperative astigmatism and endothelial cell count (ECC), central corneal thickness (CCT), graft rejection and graft failure, of which BCVA, graft rejection and graft failure were used as the primary outcome measures, and postoperative SE, astigmatism, CCT and ECC as the secondary outcome measures. Given the lack of randomized clinical trials (RCTs), cohort studies and prospective studies were considered eligible.ResultsSixteen clinical trials involving 6625 eyes were included in this review, including 1185 eyes in DALK group, and 5440 eyes in PKP group. The outcomes were analyzed using Cochrane Review Manager (RevMan) version 5.0 software. The postoperative BCVA in DALK group was significantly better than that in PKP group (OR = 0.48; 95%CI 0.39 to 0.60; p<0.001). There were fewer cases of graft rejection in DALK group than those in PKP group (OR = 0.28; 95%CI 0.15 to 0.50; p<0.001). Nevertheless the rate of graft failure was similar between DALK and PKP groups (OR = 1.05; 95%CI 0.81 to 1.36; p = 0.73). There were no significant differences in the secondary outcomes of SE (p = 0.70), astigmatism (p = 0.14) and CCT (p = 0.58) between DALK and PKP groups. And ECC in DALK group was significantly higher than PKP group (p<0.001). The postoperative complications, high intraocular pressure (high-IOP) and cataract were analyzed, fewer cases of complications occurred in DALK group than those in PKP group (high-IOP, OR 0.22, 95% CI 0.11-0.44, P<0.001) (cataract, OR 0.22; 95% CI 0.08-0.61, P = 0.004). And no cases of expulsive hemorrhage and endophthalmitis were reported.ConclusionThe visual outcomes for DALK were not equivalent to PKP. The rate of graft failure was similar between DALK and PKP. Fewer postoperative complications occurred in DALK group, indicating that compared with PKP, DALK has lower efficacy but higher safety.
| S-EPMC4310590 | biostudies-literature
Project description:PurposeTo theoretically compare corneal displacement and the von Mises (VM) stress distribution of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) for keratoconus (KC) and to evaluate the effects of residual stromal thickness (RST) and intraocular pressure (IOP) on postoperative corneal biomechanics.MethodsWe performed DALK and PK simulations using Ansys by employing anisotropic nonlinear hyperelastic corneal material properties. We analyzed corneal displacement and VM stress in DALK and PK models under IOPs of 10, 15, 20, and 25 mmHg. We established two DALK models: The ideal-type DALK ensured that postoperative central corneal thickness was constant at 560 µm and the corneal graft thickness varied with RST. The clinical-type DALK ensured that corneal grafts had the same thickness (500 µm) regardless of RST. Then we analyzed the effects of RST and IOP on postoperative corneal displacement and VM stress.ResultsCorneal displacement and VM stress were lower in the DALK than in the PK model. In the ideal-type DALK model, an increase in RST was associated with increased deformation and decreased VM stress in the healing zone, except for a RST of 0 µm. In the clinical-type DALK model, deformation and VM stress in the healing zone decreased with an increase in RST, except for a RST of 0 µm.ConclusionsDALK showed more stability than PK. For the ideal-type DALK model, an increase in RST resulted in decreased postoperative corneal biomechanics in the healing zone. For the clinical-type DALK model, corneal deformation and VM stress decreased with an increase in RST, which provides numerical evidence for the design of corneal transplantation for patients with KC.Translational relevanceIn this computational modeling study, we first theoretically compared corneal biomechanics between DALK and PK for KC. Then, the effects of RST and IOP on postoperative corneal biomechanics were investigated. Our findings provide novel insights into the optimal design for corneal transplantation for patients with KC.
| S-EPMC8363774 | biostudies-literature
Project description:PurposeTo evaluate the outcome of eyes with large Descemet's membrane (DM) perforation during deep anterior lamellar keratoplasty (DALK).MethodsA retrospective, interventional case series of 12 eyes with completed DALK, despite DM perforation larger than 4 mm in its widest dimension. The main outcome measures included graft clarity, endothelial cell density (ECD), corrected distance visual acuity (CDVA), and DM detachment.ResultsThe mean age of patients was 26.8 ± 11.4 years. Preoperative pathology included keratoconus (n = 10), macular dystrophy (n = 1), and postmicrobial keratitis corneal scar (n = 1). The average size of DM perforation was 6.5 mm ± 1.3 mm. At the end of the follow-up period (median 15 months, range 6-53 months), the mean CDVA was 0.32 ± 0.09 logMAR and the mean ECD was 1830.8 ± 299.7 cells/mm2. Nine patients (75%) developed DM detachments postoperatively and was managed by intracameral air injection once in six eyes, and twice in three eyes. Other complications included persistent localized stromal edema at the site of DM defect in one eye and Urrets Zavalia syndrome in one eye.ConclusionCompleting DALK in eyes with large DM perforation provides good visual acuity, endothelial cell count and may be superior to penetrating keratoplasty regarding long-term graft survival if confirmed in future comparative studies.
| S-EPMC8365580 | biostudies-literature