Performing Penetrating Keratoplasty Research Articles

Re-descemet membrane endothelial keratoplasty (DMEK) with preservation of the original graft after free roll in anterior chamber: A case report

IntroductionLamellar keratoplasties have had a great impact in the management of corneal edema due to endothelial dysfunction. Minimally invasive transplant techniques such as Descemet Membrane Endothelial Keratoplasty (DMEK) have helped to reduce the morbidity involved in performing penetrating keratoplasty in this type of patient. Even so, these are complex techniques that are not free of complications and require a long line of surgical learning and an even more demanding experience in postoperative management. Clinical caseAn 89-year-old woman suffering from Fuchs endothelial dystrophy and undergoing combined cataract and DMEK surgery presented stromal edema predominantly inferior and sectoral detachment of the graft 24 h after the intervention. After re-bubbling in consultations and 4 days later, the graft was observed rolled and free in the anterior chamber.She underwent re-DMEK with preservation of the original graft after 24 h, with de-epithelialization to optimize visualization. The graft was stained with trypan blue and the posterior stroma was protected with air. The graft was reimplanted under intraocular maneuvers and with an air bubble.24 h after surgery, the adhered graft was observed, with a great decrease in stromal edema. One month later, the patient had a clear cornea, persistent complete graft adhesion, and visual acuity of 0.9. ConclusionThe discovery of free roll in the anterior chamber after DMEK surgery constitutes the most complex form of graft detachment. Corneal edema as well as the arrangement of the different intraocular structures are conditions to be considered for the surgical resolution of this complication. In many cases, surgical repositioning of the graft is feasible, which means saving costs without the need to use new donor corneal tissues.

A clinical case of a combined method for correcting postkeratoplastic astigmatism of a high degree in a patient with cataract

Background. Performing penetrating keratoplasty in 100 % of cases leads to the occurrence of induced postkeratoplasty astigmatism, which can be more than 12,0 D. If cataracts occur in this category of patients, performing cataract phacoemulsification with implantation of a toric intraocular lens (tIOL) does not completely solve the problem. The use of the method of implantation of intrastromal corneal segments at stage I before cataract phacoemulsification makes it possible to reduce the degree of postkeratoplasty astigmatism and create optimal conditions for additional correction of residual postkeratoplasty astigmatism due to the implantation of tIOL during cataract phacoemulsification.The aim. To analyze the clinical and functional indicators of correction of regular high-grade postkeratoplasty astigmatism in a patient with cataracts using a combined method, including first implantation of intrastromal corneal segments and subsequent cataract phacoemulsification with implantation of toric intraocular lens using the example of a clinical case.Material and methods. A 55-year-old patient with cataracts, who had a history of undergoing penetrating keratoplasty, contacted us. According to the keratotopogram data, a regular postkeratoplasty astigmatism of 18.68 D was diagnosed. The patient underwent a combined method. At stage I, intrastromal corneal segments were implanted into the corneal graft, then after 6 months stage II was performed – cataract phacoemulsification with implantation of tIOL.Results. Six months after intrastromal corneal segments implantation, the patient’s keratometric data stabilized, and corneal astigmatism decreased to 8.98 D. Then the patient underwent cataract phacoemulsification with tIOL implantation. After 1 month, the spherical component of refraction was 0.5 D, the cylindrical component of refraction was –0.5 D, visual acuity increased to 1.0.Conclusions. A combined method for correcting regular high-grade postkeratoplasty astigmatism in a patient with cataracts showed high refractive results, stability and safety in the long-term postoperative period.

EVALUATION OF CLINICAL INDICATIONS OF PENETRATING KERATOPLASTY IN TERTIARY CARE HOSPITAL

This study aimed to evaluate the reasons for performing penetrating keratoplasty at Nishtar Hospital Multan. The research was conducted by Nishtar Medical University and Hospital in Multan, Pakistan, from December 15, 2022, to June 15, 2023. The study included one hundred patients who presented to the OPD with indications of penetrating keratoplasty. Data was analyzed using SPSS V26 software. The study found that the most common provisional diagnosis among the participants was keratoconus, affecting 25% of them. Keratoconus is a degenerative eye disease that weakens and swells the cornea into a cone shape impairs vision. Post-infective keratitis-induced corneal scar was the second most common indication for penetrating keratoplasty. In conclusion, the study reports on the indications of penetrating keratoplasty at Nishtar Hospital Multan. It found that keratoconus followed by corneal scar (post-infective keratitis) were the leading reasons for performing penetrating keratoplasty.

Outcomes of Repeat Anterior Lamellar Keratoplasty.

To describe the outcomes and complications of repeat anterior lamellar keratoplasty (ALK) after a failed primary ALK. This was a retrospective case series. Twenty-three eyes of 22 patients who underwent repeat ALK for optical indications from January 1, 1991, to December 31, 2017, were included. Clinical data were recorded from the Singapore Corneal Transplant Study database. Outcome measures were graft survival, best-corrected visual acuity (BCVA), and complications. Of the 780 cases of ALK performed for optical indications during the study period, 23 cases (2.9%) underwent repeat ALK. Primary ALK comprised of 16 deep ALK and 7 automated lamellar therapeutic keratoplasty cases. After repeat ALK, 21 eyes had further dissection down to the descemetic or predescemetic plane, whereas 2 eyes had graft exchange for failed automated lamellar therapeutic keratoplasty. The graft survival of repeat ALK was 93.2%, 86.1%, and 78.3% at 1, 3, and 5 years, respectively. There were 4 cases of graft failure with a mean time to failure of 2.0 ± 1.7 years. After the repeat ALK procedure, 63.6% and 66.7% of eyes achieved a BCVA of LogMAR +0.3 (20/40) or better at 1 and 2 years, respectively. Five eyes (17.4%) had an intraoperative microperforation. In the case of a failed ALK graft for a range of optical indications, a repeat ALK procedure offers a viable and safe surgical option with good long-term graft survival and visual outcomes, while avoiding the various disadvantages of performing penetrating keratoplasty, especially the risk of allograft endothelial rejection.

Combined penetrating keratoplasty with extraocular needle-guided haptic insertion technique

Scleral fixation of intraocular lens (SFIOL) is a challenge in eyes with opaque corneas. It is preferable to implant the IOL before performing penetrating keratoplasty. Most techniques described so far involve SFIOL following corneal trephination (open sky) which increases the risk of expulsive choroidal hemorrhage. Extraocular needle-guided haptic insertion technique involves extraocular docking of the IOL haptic into a bent 26-gauge needle followed by its exteriorization. Since this crucial step of SFIOL surgery is completely extraocular, this method can be used to safely place an SFIOL in a well-formed globe even before corneal trephination. Use of a silicone stopper over the leading haptic prevents intraocular rebound of the haptic.

Rationale for Performing Penetrating Keratoplasty Rather Than DSAEK in Patients With Bullous Keratopathy in Japan

To analyze the rationale for performing penetrating keratoplasty (PK) rather than Descemet's stripping automated endothelial keratoplasty (DSAEK) in patients with bullous keratopathy (BK) in Japan. A total of 136 eyes of 130 patients with consecutive BK were enrolled. Patients treated by DSAEK were categorized as the DSAEK group. The remaining patients were considered unsuitable for DSAEK due to the presence of risk factors, and were treated by PK (PK group). In both groups, the number of the patients and the causes of BK were analyzed. Also, specifically in the PK group, the reasons for not performing DSAEK were analyzed. The causes of BK differed significantly between the two groups (P < .001). Risk factors considered unsuitable for DSAEK include significant stromal scarring, iris abnormalities, and lens abnormalities. For successful DSAEK, risk factors and contraindications should be carefully evaluated before surgery.

Surgical intervention for corneal involvement in xeroderma pigmentosa

Xeroderma pigmentosum (XP) is a rare autosomal recessive genetic disorder characterized by solar injury to exposed skin and ocular tissues due to an enzymatic defect in the ability to repair DNA damage caused by ultraviolet (UV) light [1]. The cornea in XP may show dryness, haze, exposure keratitis, vascularization, and opacification [2]. Most patients present to the cornea clinic with a significantly scarred cornea which requires corneal transplantation for visual rehabilitation. In such cases, corneal surgeons are faced with the dilemma of performing penetrating keratoplasty (PK) versus lamellar keratoplasty (LK). Anterior LK is preferred over PK for management of corneal opacity as it eliminates the risk of endothelial rejection. The few reports on the outcomes of PK in XP are encouraging, but the feasibility and results of anterior LK in XP patients is not available in the literature. According to the only reported in vivo study of corneal endothelium in XP, the patients were found to have a decreased cell density, and an increased coefficient of variation in the cell area, compared to that of normal persons [3]. Histopathological reports of corneal buttons in XP have shown a moderate to severe decrease in endothelial cells [4]. Here we describe unusual clinical observations in two XP patients which indirectly corroborate and support the evidence that endothelial cell density may be poor in these patients. This has an implication in deciding the surgical plan (PK vs LK) for corneal opacification in XP patients.

Large-Diameter Penetrating Keratoplasty: Indications and Outcomes

To report the indications and outcomes of patients who underwent large-diameter penetrating keratoplasty (LDPK) for the management of peripheral corneal disease. A retrospective chart review and data analysis of patients who underwent LDPK was performed. A retrospective chart review of 35 eyes of 32 patients undergoing LDPK between May 2000 and December 2006 at the Cincinnati Eye Institute/University of Cincinnati was completed. Corneal grafts 8.75 mm or larger were designated as large grafts. Graft diameter ranged from 8.75 mm to 10.0 mm. Indications for cornea transplantation included keratoconus (19), pellucid marginal degeneration (two), keratoconus and pellucid marginal degeneration (five), Fuchs endothelial dystrophy (one), corneal stromal scar (one), postradial keratotomy irregular astigmatism (two), and repeat penetrating keratoplasty (five). No evidence of preoperative stromal neovascularization was seen in any eye. Five of 35 eyes had experienced one previous graft failure. Minimum follow up was 12 months (range, 12-91 months) with a mean follow up of 29.8 months. Preoperative best-corrected visual acuity was 20/100 (range, 20/25 to hand movements), and postoperative best-corrected visual acuity was 20/32 (range, 20/20-20/125). Postoperatively, 43% of patients had 20/40 or better uncorrected visual acuity. Average postoperative manifest cylinder was +2.19 D (range, none to +4.75 D) with 77% of patients having less than +3.00 D of cylinder. The postoperative immunosuppression regimen included topical corticosteroid and topical cyclosporine 0.05%. The incidence of cataract formation in our study was 14.2%. The incidence of secondary glaucoma was 8.8%. Cornea graft rejection was noted in six of 35 eyes with resolution in 4/6. Repeat cornea transplant was required in one of six eyes for severe infectious keratitis, and one of six eyes was lost to follow up. At last follow up, 33 of 35 original grafts were clear with one graft lost to follow up and one eye requiring repeat keratoplasty. No graft rejection was experienced by any patient with a history of prior graft failure. LDPK may result in less postoperative astigmatism without an increased risk of graft failure if managed correctly postoperatively. Topical cyclosporine 0.05% may be a useful adjunct to decrease the incidence of graft rejection and failure. Ophthalmologists performing penetrating keratoplasty should consider a LDPK to reduce postoperative astigmatism and improve visual acuity outcomes in their patients.

Deposit of glass fragments during femtosecond laser penetrating keratoplasty

To evaluate femtosecond laser interaction with the applanation lens during pre-programmed penetrating keratoplasty corneal cuts. Three different-shaped penetrating keratoplasty dissections were performed on edematous corneas from bank eyes using a clinical femtosecond laser system (Intralase FS60) with energies higher than 2 microJ, and the "depth into glass" parameter at 50 microm, which is defined as the length over which the laser interacts with the glass of the applanation cone in contact with the cornea. Additional full-thickness corneal incisions were obtained with an experimental laser source with technical characteristics similar to the clinical laser. Following cutting, tissue sections were examined by optical microscopy (OM), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). After the procedure, the cones were examined by optical and scanning electron microscopy (SEM). A control was obtained by repeating the procedures and stopping the laser at the cornea-lens interface. OM and TEM analysis of the tissue showed the presence of solid particles of a maximum dimension of 1.5 mum on the epithelium and the anterior stroma, regardless of the laser system used to cut. The EELS technique revealed their composition as silicon dioxide. We believe that the fragments originate from the applanation cone, which is machined by the laser interacting with the glass in contact with cornea. This is consistent with the structures observed on the lens by OM and SEM. Radial and circumferential tracks on the surface of the lens are visible, corresponding to the laser path in penetrating keratoplasty protocols. No particles were found in the control samples. When performing penetrating keratoplasty corneal cuts by infra-red femtosecond laser, the applanation lens in contact with the cornea is machined by the laser depending on the system parameters. As a consequence, microscopic glass fragments are created, which may remain in the tissue. This unwanted effect can be avoided by stopping the procedure at the lens-cornea interface.

Clinical study on the recurrence of fungal keratitis after lamellar keratoplasty

To study the characters, diagnosis, treatment and risk factors of the recurrence of fungal keratitis after lamellar keratoplasty (LKP). In this nonrandomized retrospective case series, two hundred and eighteen cases of fungal keratitis were undertaken partial LKP from January 1998 to July 2005. The case history was inquired in detail preoperatively. A trephine with diameter 0. 5 mm larger than the area of fungal infection was used to incise the lamellar corneal ulcer, and the hyphae of some cases were inspected with microscope during the operation. The recurrence of fungal keratitis was observed after the surgery. Medical treatment and/or operation were used in the management of recurrent cases. The risk factors for the recurrence of fungal keratitis after LKP, such as fungal species, glucocorticoid or immunosuppressant therapy, hypopyon or endothelial plague, were also analyzed. Seventeen cases (7.80%) recurred within 2 weeks after surgery and mainly (15 cases) within 1 week. The recurrence displayed with increased local irritation and hypha infiltration on recipient LKP bed. All recurrent fungal infections were controlled by performing penetrating keratoplasty (PKP). Risk factor analysis: (1) The recurrent rate of Aspergillus infection (19.23%) was higher than that in Fusarium infection (5.63%) (P = 0.0323). (2) The recurrence rate of cases treated with glucocorticoid or immunosuppressant preoperatively (21.70%) was much higher than that in non-treated cases (6.15%) (P =0.0219). (3) The recurrence rate of cases with hypopyon or endothelial plague preoperatively (17.02%) was much higher than that without these signs (5.26%) (P = 0.0134). The recurrence of fungal keratitis after LKP occurs mainly within the 1st week. Aspergillus infection, glucocorticoid or immunosuppressant therapy, hypopyon or endothelial plague are the risk factors for LKP.

Donor Factors Associated with Epithelial Defects After Penetrating Keratoplasty

The records of 39 patients undergoing 40 consecutive penetrating keratoplasties were reviewed to identify donor factors that might correlate with the presence of an epithelial defect on the first postoperative day. Of the 40 transplanted corneas, 13 (32.5%) had no epithelial defect, 18 (45%) had some epithelial defect, and nine (22.5%) had a total epithelial defect 1 day postoperatively. The status of the epithelium was correlated with several donor factors. The only factor that had a statistically significant association with the degree of epithelial defect was the time interval from preservation to surgery (p = .001). Based on a logistic regression model, the probability of having an epithelial defect 1 day after penetrating keratoplasty increased with respect to longer storage times. These results may aid the surgeon in the selection of donor tissue, particularly when performing penetrating keratoplasty on patients with ocular surface disorders.

Keratoplastik in der Privatpraxis

The problems associated with performing penetrating keratoplasty in private practice are briefly discussed: access to an eye bank, high-risk patients, immunosuppressive therapy, complications, and results. One negative aspect is the relatively high incidence (10%) of primary graft failure, but allograft reactions are less frequent (5%). The best results are obtained in keratoconus cases.

Penetrating Keratoplasty After Radial Keratotomy

ABSTRACT: Irregular astigmatism, separation of the radial incisions, and unique wound closure problems have occurred when performing penetrating keratoplasty on eyes that have undergone previous radial keratotomy. To better understand the characteristics of this procedure, penetrating keratoplasty was performed in human cadaver eyes that had previously undergone radial keratotomy. A variety of suturing techniques were tried in order to determine the most effective method of penetrating keratoplasty wound closure. Technical difficulties encountered in performing penetrating keratoplasty after radial keratotomy included: separation of the radial incisions during trephination, resulting in irregular wound edges and peripheral host corneal wound undermining; peripheral host corneal flaccidity with tissue segmentation; poor wound edge apposition; leakage at the junction of radial incisions with donor corneal tissue; and, anterior wound gape of the radial incisions after fixation of the graft with interrupted cardinal sutures. Recommendations made for performing penetrating keratoplasty after radial keratotomy include: the use of preplaced transverse sutures across each radial incision, one 0,5 mm peripheral to the graft wound and the other 1.0 mm from the corneal Hmbus; interrupted radial cardinal sutures between radial keratotomy incisions; meticulous closure of the radial keratotomy-graft wound junctions using a combination of apposition and overlying compression sutures. The double-crossed interrupted and the double-running antitorque suturing techniques were found to be the most effective methods of penetrating keratoplasty wound closure in eyes that have undergone previous radial keratotomy.