Descemet Membrane Endothelial Patching: Selective Endothelial Replacement in Eyes With Localized Endothelial Dysfunction.

ABSTRACT: Descemet membrane (DM) endothelial keratoplasty is considered the gold standard for treating corneal endothelial decompensation and is a true like-for-like replacement. Not all causes of endothelial dysfunction are global, with conditions such as viral endotheliitis affecting discrete populations of endothelial cells. In this study, endothelial grafts matching the area of dysfunction were produced to preserve healthy host cells and limit the immunological burden of new grafts. We have termed this modified DM endothelial keratoplasty procedure DM endothelial patching.

Dupilumab-Induced, Tralokinumab-Induced, and Belantamab Mafodotin-Induced Adverse Ocular Events-Incidence, Etiology, and Management.

ABSTRACT: Emerging monoclonal antibody therapies are assuming greater importance in the management of severe and refractory forms of immunity-driven and oncological disorders. However, some have been found to induce adverse ocular events (AOEs) leading to discontinuation of treatment or additional multidisciplinary management. We present the current knowledge concerning AOEs associated with 3 monoclonal antibody therapies: dupilumab, tralokinumab, and belantamab mafodotin. We examine the manifestations of their AOEs, proposed pathophysiological mechanisms, and current treatment recommendations. We identified and reviewed all studies for dupilumab, tralokinumab, and belantamab mafodotin using the keywords "dupilumab," "tralokinumab," "belantamab mafodotin," "conjunctivitis," and "keratopathy" from January 2016 to November 2021. Conjunctivitis was the most frequently reported AOE in patients with atopic dermatitis receiving dupilumab or tralokinumab. Mild cases were managed with warm compresses for associated meibomian gland dysfunction, artificial tears, and antihistamine/mast cell stabilizer eye drops. In more severe cases, additional anti-inflammatory therapy, with corticosteroid eye drops or ointments, or topical calcineurin inhibitors-such as tacrolimus or ciclosporin-were required. Patients with resistant or refractory multiple myeloma treated with belantamab mafodotin often developed keratopathy, which could necessitate contact lens fitting, or for cycles of belantamab mafodotin to be delayed.

A goat eye, wet lab model for training in Descemet membrane endothelial keratoplasty.

Here we describe a new, non-human, ex-vivo model (goat eye model) for training surgeons in DMEK surgeons. In a wet lab setting, goat eyes were used to obtain a pseudo-DMEK graft of 8 mm from the goat lens capsule that was injected into another goat eye with the same maneuvers described for human DMEK. The DMEK pseudo-graft can be easily prepared, stained, loaded, injected, and unfolded into the goat eye model reproducing the similar maneuvers used for DMEK in a human eye, except for the descemetorhexis, which cannot be performed. The pseudo-DMEK graft behaves similar to human DMEK graft and useful for surgeons to experience and understand steps of DMEK early in learning curve. The concept of a non-human ex-vivo eye model is simple and reproducible and obviates the need for human tissue and the issues of poor visibility in stored corneal tissue.

DMEK surgical training: An instructional guide on various wet-lab methods.

Descemet membrane endothelial keratoplasty (DMEK) is a partial-thickness corneal transplantation procedure that involves selective transplantation of the Descemet membrane and endothelium. DMEK offers significant advantages over other keratoplasty techniques, such as faster visual rehabilitation, better final visual acuity due to minimal optical interface effects, lower risk of allograft rejection, and less long-term dependence on topical steroids. Despite all its advantages, DMEK has been found to be more challenging than other corneal transplantation techniques, and its steep learning curve appears to be an obstacle to its widespread use and adoption by corneal surgeons worldwide. DMEK surgical training laboratories (wet labs) provide a window of opportunity for surgeons to learn, prepare, manipulate, and deliver these grafts in a risk-free environment. Wet labs are a significant learning tool, especially for those institutions that have limited tissue availability in their local centers. We provide a step-by-step guide for preparing DMEK grafts using different techniques on human and nonhuman models with instructional videos. This article should eventually help the trainees and the educators understand the requirements for performing DMEK and conducting a DMEK wet lab and develop their skills and interests from a wide variety of available techniques.

Argon laser iridoplasty to improve visual function following multifocal intraocular lens implantation.

PURPOSE: To describe the use of argon laser iridoplasty following implantation of a multifocal intraocular lens (IOL) to improve visual function. METHODS: Argon laser spots of 500-mW power, 500-µm spot diameter, and 500-ms duration were placed in the midperipheral iris in the area in which the iris was encroaching on the IOL. RESULTS: Argon laser iridoplasty provided statistically significant improvement in visual function including corrected distance visual acuity (CDVA) and subjective quality of vision in 14 eyes from 11 patients. Mean CDVA improved from 0.24 (20/35 Snellen) to 0.10 (20/25 Snellen) logMAR (P<.0001), and mean subjective quality of vision improved from 2.9 to 7.5 (P<.0001). CONCLUSIONS: Argon laser iridoplasty should be considered in correcting visual problems associated with decentered multifocal IOLs.

Use of a Single Radial Incision to Improve Curvature Matching and Graft Adhesion in Descemet Membrane Endothelial Keratoplasty in a Patient With Keratoconus.

PURPOSE: The purpose of this study was to report a novel surgical technique for altering donor Descemet membrane endothelial keratoplasty (DMEK) curvature to match host posterior stroma in a patient with advanced keratoconus (KC) and endothelial decompensation. METHODS: We report a 56-year-old man with Fuch endothelial dystrophy and KC, who underwent DMEK due to endothelial decompensation. A triangular area of graft detachment centered on the apex of cones persisted after repeat gas tamponade. A radial incision from the graft edge to the apex was used to allow overlapping of the graft, thereby increasing the grafts curvature. RESULTS: The use of a radial incision in the Descemet membrane (DM) graft was made to allow the graft overlap and adapt to the new shape. By matching the donor curvature to that of the hosts posterior curvature, full adhesion of the graft was achieved with the use of a short-acting air bubble by 1 week after the procedure. CONCLUSIONS: The mismatch in the curvature of the DM graft and the host posterior corneal surface, in cases with KC or very steep corneas, should be taken into consideration because it can lead to redundancy folds. These can result in atypical, conical detachments, distinct from the typical peripheral detachments seem commonly in DMEK. A single radial incision in the DM graft combined with air tamponade is a feasible treatment option in cases where DMEK fails to attach because of apparent curvature mismatch between the donor and host.

Near infra-red labelling and tracking of corneal endothelial cells in-vivo.

Following corneal transplantation, there is an initial, rapid decline in corneal endothelial cells (CECs) following surgery. Direct imaging of post-transplantation endothelial cells is only possible weeks after surgery and with a limited field of view. We have developed a labelling approach using 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DIR) dye solution, that enables tracking of labelled CECs in vivo for at least 1 month. Initial in vitro optimization, with assessments of dye concentration on fluorescence, cellular toxicity and cell migration, performed in propagated primary CECs. Subsequently, in vivo evaluation of cellular labelling was assessed within a rabbit wound healing model. Finally, real-time visualization of human cadaver donor tissue incubated in DIR transplanted into rabbits was achieved using a clinical confocal microscope. Results revealed detectable fluorescence increased with concentration to a plateau of 100 µg/ml, with no toxicity of CECs at any concentration evaluated. DIR-labelled CECs were detectable in vivo up to 1 month, and transplanted labelled donor graft could be visualized and were trackable in vivo. Acute endothelial rejection in 1 rabbit was evidenced by detectable DIR positive cells within the anterior chamber. DIR imaging allowed for detailed imaging of the transplanted human corneal endothelium, and enabled non-invasive observation of the corneal endothelial morphology following transplantation.

Stability of eyelid height after graded anterior-approach lid lowering for dysthyroid upper lid retraction.

OBJECTIVE: To investigate the outcome of a modified anterior approach surgical procedure for the correction of primary upper eyelid retraction in thyroid eye disease. METHODS: A retrospective review of 52 consecutive cases (in 32 patients) of anterior-approach graded upper lid lowering for the treatment of primary eyelid retraction, carried out at Moorfields Eye Hospital between 2006-2009 was conducted. Measurements of upper margin-reflex distance (MRD), upper lid skin crease height and skin fold height were taken from clinical records and photographs. A comparison between pre-operative and both early and late post-operative measurements was conducted, with a maximal follow-up of 12 months. Surgery was considered successful when all of the following criteria were met; an upper lid margin covering 0.5-1.5 mm of the superior cornea in the 12 o'clock position, smooth eyelid contour, skin crease height within 6-10 mm or upper lid skin fold within 2-5 mm of the lid margin, symmetry of lid position (difference in MRD of < 1 mm between both eyes) and patient satisfaction. RESULTS: A successful outcome was achieved in 86.5% (45/52) of lids with a single procedure. For the whole group, the mean MRD was 7.0 mm pre-operatively and 3.6 mm at 1 month after surgery. The corresponding values from photographic estimates were 6.5 mm and 3.6 mm, respectively. These values remained stable over the maximum follow-up period of 12 months. Under-correction occurred in 6/52 (11.5%) lids, one of which had persistent lateral flare, whereas over-correction occurred in 1/52 (2%). CONCLUSIONS: The described surgical approach produces reasonably predictable and stable outcome for upper eyelid lowering in patients with thyroid eye disease.

Corneal transplantation after failed grafts: Options and outcomes.

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Because of the large number of transplants, corneal graft failure has become one of the most common indications for corneal transplantation. The relatively recently developed lamellar transplant techniques have brought about specific potential complications leading to graft failure that may require different approaches to repeat transplantation other than penetrating keratoplasty. On the other hand, these new lamellar techniques also provide novel ways of rescuing failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as reduced intraoperative risks and faster visual rehabilitation. We summarize the incidence and risk factors of graft failure for penetrating and lamellar (stromal and endothelial) corneal transplants and discuss the various surgical alternatives currently available to rescue such failed grafts, with a focus on the reported outcomes and limitations.

Descemet Membrane Endothelial Keratoplasty Under Failed Penetrating Keratoplasty Without Host Descemetorhexis for the Management of Secondary Graft Failure.

PURPOSE: To evaluate the safety and efficacy of the treatment of secondary graft failure in penetrating keratoplasty (PK) by performing Descemet membrane endothelial keratoplasty (DMEK) without host descemetorhexis. METHODS: This is a retrospective case series study of 8 eyes from 8 patients who underwent non host Descemet membrane stripping DMEK surgery under a previously failed PK. The DMEK graft diameter was either matched or 0.25 to 0.5 mm undersized in relation to the PK diameter. Six-month postoperative data are presented. Primary outcome measures were safety and anatomical success. RESULTS: No intraoperative complications were registered. Postoperatively, 1 case developed a PK host-donor junction dehiscence in relation to a previous early suture removal, requiring PK resuturing and DMEK rebubbling. Only 1 additional case required DMEK rebubbling. No primary graft failure was detected, and all cases achieved full PK transparency within 2 weeks. Corrected distance visual acuity improved from a median of counting fingers (CF-0.2) to 0.57 (0.05-0.7). Median central corneal thickness improved from 650.5 (497-897) to 464 (372-597) µm. Median endothelial cell density was 1080 (581-2043) cells/mm. Rebubbling rate (25%) was lower than that previously reported. All patients had extensive preoperative ocular comorbidity. CONCLUSIONS: DMEK under PK without host descemetorhexis is a feasible surgical alternative for the treatment of graft failure after PK. It is associated with equivalent levels of efficacy and safety compared with Descemet membrane stripping DMEK techniques but simplifies the surgical procedure and avoids potential intraoperative complications associated with Descemet stripping. Further studies with a larger sample and a longer follow-up are necessary to confirm our preliminary outcomes.

A Novel Approach of Harvesting Viable Single Cells from Donor Corneal Endothelium for Cell-Injection Therapy.

Donor corneas with low endothelial cell densities (ECD) are deemed unsuitable for corneal endothelial transplantation. This study evaluated a two-step incubation and dissociation harvesting approach to isolate single corneal endothelial cells (CECs) from donor corneas for corneal endothelial cell-injection (CE-CI) therapy. To isolate CECs directly from donor corneas, optimization studies were performed where donor Descemet's membrane/corneal endothelium (DM/CE) were peeled and incubated in either M4-F99 or M5-Endo media before enzymatic digestion. Morphometric analyses were performed on the isolated single cells. The functional capacities of these cells, isolated using the optimized simple non-cultured endothelial cells (SNEC) harvesting technique, for CE-CI therapy were investigated using a rabbit bullous keratopathy model. The two control groups were the positive controls, where rabbits received cultured CECs, and the negative controls, where rabbits received no CECs. Whilst it took longer for CECs to dislodge as single cells following donor DM/CE incubation in M5-Endo medium, CECs harvested were morphologically more homogenous and smaller compared to CECs obtained from DM/CE incubated in M4-F99 medium (p < 0.05). M5-Endo medium was hence selected as the DM/CE incubation medium prior to enzymatic digestion to harvest CECs for the in vivo cell-injection studies. Following SNEC injection, mean central corneal thickness (CCT) of rabbits increased to 802.9 ± 147.8 µm on day 1, gradually thinned, and remained clear with a CCT of 385.5 ± 38.6 µm at week 3. Recovery of corneas was comparable to rabbits receiving cultured CE-CI (p = 0.40, p = 0.17, and p = 0.08 at weeks 1, 2, and 3, respectively). Corneas that did not receive any cells remained significantly thicker compared to both SNEC injection and cultured CE-CI groups (p < 0.05). This study concluded that direct harvesting of single CECs from donor corneas for SNEC injection allows the utilization of donor corneas unsuitable for conventional endothelial transplantation.

Double-Line Reflection Pattern as a Simple Method to Determine Graft Orientation of Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To describe a simple finding, consisting of a double-line reflection from the graft inside the anterior chamber, that can be used to determine the correct donor tissue orientation in Descemet membrane endothelial keratoplasty: which we would like to call Berrospi's sign. METHODS: Evaluation of the presence of linear reflection from the donor tissue when implanted in the anterior chamber. RESULTS: A distinctive double-line reflection pattern was identified when careful observation of the curls of the scroll was performed under the surgical microscope, which was a confirmatory sign that the graft was in the correct position. CONCLUSIONS: This method of confirming correct graft orientation requires no additional procedures, equipment, or manipulation of the donor tissue and can be used in conjunction with other marking methods already described.

Allogeneic Descemet's Membrane Transplantation Enhances Corneal Endothelial Monolayer Formation and Restores Functional Integrity Following Descemet's Stripping.

Purpose: To characterize the differences in corneal endothelial wound healing in the presence or absence of Descemet's membrane (DM), in vivo. Methods: New-Zealand white rabbits were subjected to 7-mm endothelial wound either by scraping (n = 8; DM intact), peeling (n = 6; DM removed), or a combinatory scrape/peel wound (n = 6). In a second experiment, rabbits underwent peel wound with immediate transplantation of pure decellularized human DM (n = 4). In vivo endothelial migration was assessed via trypan blue staining. Recovery of corneal clarity and thickness was performed by using slit-lamp biomicroscopy and optical coherence tomography. Cell proliferation, phenotype, and morphology were assessed by using immunofluorescence and scanning electron microscopy. Results: In vivo wound closure was faster in the presence of DM; 25.4% ± 1.4%/d versus 5.5% ± 0.6%/d (P < 0.0001). At day 8, complete wound closure was seen in all of the scrape samples but none of the peel group, with wound closure preceding clinical recovery by approximately 6 days in the scrape group. Endothelial cells in the scraped areas reformed functional monolayers capable of restoring corneal thickness and transparency whilst those in the peeled area underwent mesenchymal-like transformation resulting in scar formation. Transplanting decellularized DM in animals receiving a peel wound resulted in clarity and thickness comparable to the scrape group. Endothelial proliferation (Ki67 +ve cells) was higher in scraped versus peeled areas: 54.7% ± 3.5% vs. 8.8% ± 0.7%, (P < 0.01). Conclusions: The presence of DM promoted endothelial wound healing, proliferation, and maintenance of a normal phenotype. DM transplantation recovered the abnormal peel phenotype back to that observed after endothelial scraping.

Real-time assessment of corneal endothelial cell damage following graft preparation and donor insertion for DMEK.

PURPOSE: To establish a method for assessing graft viability, in-vivo, following corneal transplantation. METHODS: Optimization of calcein AM fluorescence and toxicity assessment was performed in cultured human corneal endothelial cells and ex-vivo corneal tissue. Descemet membrane endothelial keratoplasty grafts were incubated with calcein AM and imaged pre and post preparation, and in-situ after insertion and unfolding in a pig eye model. Global, macroscopic images of the entire graft and individual cell resolution could be attained by altering the magnification of a clinical confocal scanning laser microscope. Patterns of cell loss observed in situ were compared to those seen using standard ex-vivo techniques. RESULTS: Calcein AM showed a positive dose-fluorescence relationship. A dose of 2.67µmol was sufficient to allow clear discrimination between viable and non-viable areas (sensitivity of 96.6% with a specificity of 96.1%) and was not toxic to cultured endothelial cells or ex-vivo corneal tissue. Patterns of cell loss seen in-situ closely matched those seen on ex-vivo assessment with fluorescence viability imaging, trypan blue/alizarin red staining or scanning electron microscopy. Iatrogenic graft damage from preparation and insertion varied between 7-35% and incarceration of the graft tissue within surgical wounds was identified as a significant cause of endothelial damage. CONCLUSIONS: In-situ graft viability assessment using clinical imaging devices provides comparable information to ex-vivo methods. This method shows high sensitivity and specificity, is non-toxic and can be used to evaluate immediate cell viability in new grafting techniques in-vivo.

Regulatory Compliant Tissue-Engineered Human Corneal Endothelial Grafts Restore Corneal Function of Rabbits with Bullous Keratopathy.

Corneal transplantation is the only treatment available to restore vision for individuals with blindness due to corneal endothelial dysfunction. However, severe shortage of available donor corneas remains a global challenge. Functional regulatory compliant tissue-engineered corneal endothelial graft substitute can alleviate this reliance on cadaveric corneal graft material. Here, isolated primary human corneal endothelial cells (CEnCs) propagated using a dual media approach refined towards regulatory compliance showed expression of markers indicative of the human corneal endothelium, and can be tissue-engineered onto thin corneal stromal carriers. Both cellular function and clinical adaptability was demonstrated in a pre-clinical rabbit model of bullous keratopathy using a tissue-engineered endothelial keratoplasty (TE-EK) approach, adapted from routine endothelial keratoplasty procedure for corneal transplantation in human patients. Cornea thickness of rabbits receiving TE-EK graft gradually reduced over the first two weeks, and completely recovered to a thickness of approximately 400 µm by the third week of transplantation, whereas corneas of control rabbits remained significantly thicker over 1,000 µm (p < 0.05) throughout the course of the study. This study showed convincing evidence of the adaptability of the propagated CEnCs and their functionality via a TE-EK approach, which holds great promises in translating the use of cultured CEnCs into the clinic.

Global cell-by-cell evaluation of endothelial viability after two methods of graft preparation in Descemet membrane endothelial keratoplasty.

PURPOSE: To describe a novel method of global cell viability assessment for Descemet membrane endothelial keratoplasty (DMEK) and the comparison of two contemporary methods of donor tissue preparation. METHODS: DMEK transplants were prepared using two different methods: liquid bubble separation and manual peeling (n=8 each group). Samples were incubated with Hoechst, calcein-AM and ethidium homodimer prior to mounting on a curved imaging chamber. Z-stacked fluorescence microscopy images were combined to produce an in-focus global image capable of resolving all cell nuclei. Image processing software was used to define a calcein-positive live cell area, count all cell nuclei within this area and subtract ethidium-positive dead cells to derive the total viable endothelial cell count. Corrected global cell density was calculated by dividing the number of viable cells by the graft area, which had been corrected for imaging a curved surface. RESULTS: Corrected global cell density was lower than the central endothelial cell density in both groups: 85.5% of the pre-preparation central endothelial cell density in the peel group and 75.8% in the bubble group. Corrected global cell density was significantly lower in the liquid bubble separation group than in the peel group (p=0.04). CONCLUSIONS: Eye bank estimations of central endothelial cell density overestimate true cell density after graft preparation in DMEK. A peel method is less damaging and more consistent than a liquid bubble method. Cell loss correlated strongly with the degree of stromal hydration prior to bubble separation in the liquid bubble group.

Organ culture storage of pre-prepared corneal donor material for Descemet's membrane endothelial keratoplasty.

PURPOSE: To evaluate the effect of media composition and storage method on pre-prepared Descemet's membrane endothelial keratoplasty (DMEK) grafts. METHODS: 50 corneas were used. Endothelial wound healing and proliferation in different media were assessed using a standard injury model. DMEK grafts were stored using three methods: peeling with free scroll storage; partial peeling with storage on the stroma and fluid bubble separation with storage on the stroma. Endothelial cell (EC) phenotype and the extent of endothelial overgrowth were examined. Global cell viability was assessed for storage methods that maintained a normal cell phenotype. RESULTS: 1 mm wounds healed within 4 days. Enhanced media did not increase EC proliferation but may have increased EC migration into the wounded area. Grafts that had been trephined showed evidence of EC overgrowth, whereas preservation of a physical barrier in the bubble group prevented this. In grafts stored in enhanced media or reapposed to the stroma after trephination, endothelial migration occurred sooner and cells underwent endothelial-mesenchymal transformation. Ongoing cell loss, with new patterns of cell death, was observed after returning grafts to storage. Grafts stored as free scrolls retained more viable ECs than grafts prepared with the fluid bubble method (74.2± 3% vs 60.3±6%, p=0.04 (n=8). CONCLUSION: Free scroll storage is superior to liquid bubble and partial peeling techniques. Free scrolls only showed overgrowth of ECs after 4 days in organ culture, indicating a viable time window for the clinical use of pre-prepared DMEK donor material using this method. Methods for tissue preparation and storage media developed for whole corneas should not be used in pre-prepared DMEK grafts without prior evaluation.

Femtosecond Laser-Assisted Deep Lamellar Endothelial Keratoplasty: A New Approach to a Forgotten Technique.

PURPOSE: To review indications and clinical results for a hybrid deep lamellar endothelial keratoplasty (Femto-DLEK) technique combining contemporary donor tissue preparation and implantation techniques with femtosecond laser-assisted dissection of the host tissue. METHODS: A retrospective analysis of consecutive cases of Femto-DLEK performed between 2011 and 2014 at Moorfields Eye Hospital, London, was conducted. All patients underwent manifest refraction and optical coherence tomography examination at their most recent review visit. Secondary interventions, graft rejection, and graft failure were recorded alongside corrected distance visual acuity. RESULTS: Femto-DLEK was performed in 7 eyes of 7 cases. Mean postoperative follow-up duration was 19 months. Indications included revision of deep anterior lamellar keratoplasty (n = 4), revision of failed Descemet stripping endothelial keratoplasty in cases with an anterior chamber intraocular lens (n = 2), and primary surgery in cases of dense posterior stromal copper deposition. All corneas were recorded as clear by 6 weeks after surgery. Median (range) preoperative corrected distance visual acuity was 6/60 (6/9-1/60), which improved to 6/9 (6/6-6/24) at final review. Tissue bridges requiring significant additional manual lamellar dissection were present in all 4 cases in which deep stromal femtosecond laser lamellar dissection was performed. Femtosecond laser host dissection in the remaining cases was restricted to only a posterior side-cut. CONCLUSIONS: Femto-DLEK is a useful alternative endothelial keratoplasty modality for a narrow range of indications. The femtolaser posterior side-cut facilitates DLEK, but further development of the Femto-DLEK technique is required to optimize the combination with deep lamellar host dissection.

Study of fluid ingress through clear corneal incisions following phacoemulsification with or without the use of a hydrogel ocular bandage: a prospective comparative randomised study.

PURPOSE: To assess the use of a hydrogel ocular bandage (HOB) on clear corneal incisions in phacoemulsification cataract surgery and determine whether HOB reduces ocular surface contaminants ingress after routine surgery. METHODS: In this prospective randomized controlled study, thirty eyes of patients undergoing uneventful phacoemulsification were recruited consecutively and randomly assigned to have a HOB applied to the corneal incision at the end of the surgery or not. At the end of the surgery, trypan blue (TRB) was instilled on the ocular surface, aqueous fluid was aspirated from the anterior chamber (AC) and its optical density was measured using ultraviolet spectrophotometry. The corneal incisions were examined postoperatively using anterior segment optical coherence tomography. Main outcome measures were concentration of TRB in the AC, corneal incision architecture, intraocular pressure (IOP) and Seidel test. RESULTS: All incisions were Seidel negative. The mean IOP in the immediate postoperative period was 18.1 ± 5.48 mmHg for the intervention group and 16.9 ± 5.7 mmHg for the control group (p > 0.05). No architectural differences of the incisions between the two groups were noted. The total mean length of the three-step corneal incisions in the two groups was 2261.2 ± 96.92 µm and 2263 ± 119.75 µm, respectively (p > 0.05). No trace of TRB was detected in any of the samples. CONCLUSION: Proper surgical wound construction without the use of a HOB is efficient in preventing the ingress of fluid through the main corneal incision postoperatively.