Massimo Busin

A Modified Technique for Descemet Membrane Stripping Automated Endothelial Keratoplasty to Minimize Endothelial Cell Loss

In an attempt to enhance postoperative survival of donor endothelium, the conventional technique for Descemet membrane stripping automated endothelial keratoplasty (DSAEK) was modified using the prototype of a glide specially designed to facilitate graft delivery and minimize surgical trauma. Instead of using the so-called taco technique, the Busin glide is loaded with the donor lamella, and a microincision forceps is inserted into a temporal side entry and passed across the anterior chamber, exiting through a nasal clear cornea tunnel to grab the graft and drag it into the eye. In 10 patients who underwent DSAEK, mean (SD) postoperative endothelial cell loss was 20.0% (2.6%) at 6 months, 23.5% (2.8%) at 12 months, and 26.4% (2.7%) at 18 to 24 months. Reduced trauma to the graft using our modified technique limits endothelial cell loss after DSAEK to the level recorded after conventional penetrating keratoplasty (PK).

Comparison of the Effects of Viscoat and Healon on Postoperative Intraocular Pressure

We compared the effects of Viscoat and Healon on postoperative increases in intraocular pressure in patients undergoing uncomplicated extracapsular cataract extraction with posterior chamber intraocular lens implantation in a prospective, randomized, single-masked study. Eleven eyes received Viscoat and 13 received Healon. The Viscoat or Healon was aspirated from the anterior chamber with the irrigation-aspiration tip of an automated irrigation-aspiration system at the end of the procedure. No prophylactic intraoperative or postoperative ocular hypotensive agents were used. Intraocular pressure was measured at three, six, 12, and 24 hours postoperatively. Compared with preoperative intraocular pressure, postoperative intraocular pressure was significantly increased in both the Viscoat group and the Healon group. Some postoperative intraocular pressures were as high as 50 to 60 mm Hg, despite removal of the viscoelastic substance at the end of surgery. There was no significant difference in the postoperative intraocular pressures of the Viscoat group and the Healon group.

Ultrathin Descemet's Stripping Automated Endothelial Keratoplasty with the Microkeratome Double-Pass Technique: Two-Year Outcomes

PURPOSE To evaluate the outcomes and graft survival rates after ultrathin (UT) Descemets stripping automated endothelial keratoplasty (DSAEK) using the microkeratome-assisted double-pass technique. DESIGN Prospective, consecutive, interventional case series. PARTICIPANTS Patients with endothelial decompensation of various causes (Fuchs endothelial dystrophy, pseudophakic or aphakic bullous keratopathy, failed previous graft, herpetic endotheliitis, or buphthalmus; n = 285 grafts). INTERVENTION Donor preparation was performed using the microkeratome-assisted double-pass technique. Stripping of the Descemets membrane was performed under air and the graft was delivered into the anterior chamber using the pull-through technique through a 3-mm clear-cornea incision using a modified Busin glide. MAIN OUTCOME MEASURES Best spectacle-corrected visual acuity (BSCVA), manifest refraction, endothelial cell density, and graft thickness (GT). RESULTS Excluding all eyes with pre-existing ocular comorbidities, mean BSCVA at 3, 6, 12, and 24 months was 0.16, 0.11, 0.08, and 0.04 logarithm of the minimum angle of resolution units, respectively. The percentage of patients achieving BSCVA of 20/20 or better at 3, 6, 12, and 24 months was 12.3%, 26.3%, 39.5%, and 48.8%, respectively. A statistically significant (P < 0.0001) hyperopic shift of 0.78 ± 0.59 diopters (D; range, -0.75 to 1.75 D) was found at 1 year. The endothelial cell loss at 3, 6, 12, and 24 months was 29.8 ± 14.3%, 33 ± 15.5%, 35.6 ± 14.1%, and 36.6 ± 16.0%, respectively. The mean central GT recorded 3 months after surgery was 78.28 ± 28.89 μm. Complications included microkeratome failure to achieve perfect dissection in 21 donor tissues (7.2%), with 6 (2.1%) being discarded; total graft detachment in 11 cases (3.9%); primary failure in 4 cases (1.4%); and secondary failure in 4 additional cases (1.4%). Kaplan-Meier cumulative probability of a rejection episode at 3, 6, 12, and 24 months was 0%, 0.4%, 2.4%, and 3.3%, respectively. CONCLUSIONS The visual outcomes of UT DSAEK are comparable with those published for Descemets membrane endothelial keratoplasty and better than those reported after DSAEK in terms of both speed of visual recovery and percentage of patients with 20/20 final visual acuity. However, unlike with Descemets membrane endothelial keratoplasty, preparation and delivery of donor tissue are neither difficult nor time consuming. Complications of UT DSAEK do not differ substantially from those recorded with standard DSAEK but are much less frequent than those reported after Descemets membrane endothelial keratoplasty. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Microkeratome-assisted preparation of ultrathin grafts for descemet stripping automated endothelial keratoplasty.

PURPOSE To compare three microkeratome-assisted techniques for the preparation of ultrathin (UT) grafts for Descemet stripping automated endothelial keratoplasty. METHODS After dissection with a 300-μm microkeratome head in 40 donor tissues, a second cut was performed with a 130-μm head either after manual stromal hydration (group A, n = 10) or osmotic hydration at the eye bank (group B, n = 10) or with a 50- or 90-μm head, depending on residual bed thickness (group C, n = 10); no further dissection was performed in the control group (group D, n = 10). Corneal thickness and endothelial cell (EC) count were determined at all appropriate stages. Statistical analysis was performed using a Fisher exact test. RESULTS Final graft thicknesses in groups A (89.1 ± 34.1μm), B (84.1 ± 18.6 μm), and C (72.1 ± 10.1 μm) were significantly lower than in group D (201.9 ± 25.3 μm) (P < 0.001). EC loss did not differ significantly among the groups. Multiple areas of Descemet detachment were seen in 4 of 10 corneas of group A. CONCLUSIONS All methods proved equally efficient in producing UT grafts, but stromal hydration induced tissue structural changes. EC loss was unaffected by the additional manipulation required to prepare UT grafts.

Is chronic intraocular inflammation after lens implantation of bacterial origin

In an effort to better understand the cause of chronic intraocular inflammation after intraocular lens (IOL) implantation, both scanning and transmission electron microscopy were used to compare 1 anterior chamber, 1 iris-fixated, and 3 posterior chamber IOLs removed for this condition between 2 and 16 months after implantation with 8 IOLs explanted for other reasons (decentration in 4 cases, bullous keratopathy in 4 cases). Colonization with non-slime-producing, as well as slime-producing bacteria (1 case) in the presence of a thin membranous structure of cellular origin (multinucleated giant cells and macrophage-like cells) was demonstrated on all of the 5 IOLs explanted from inflamed eyes. Neither bacteria nor membranous structures could be identified on the IOLs removed because of dislocation or from eyes with bullous keratopathy. These observations indicate that bacterial colonization and the consequent host response may be characteristic features of many otherwise unexplained cases of intraocular inflammation after IOL implantation.

Anterior Segment Optical Coherence Tomography–Guided Big-Bubble Technique

PURPOSE To evaluate the feasibility of intraoperative anterior segment (AS) optical coherence tomography (OCT) for quantification of the corneal depth reached with the dissecting cannula used for deep anterior lamellar keratoplasty, as well as its correlation with the success rate of big-bubble formation. DESIGN Retrospective, noncomparative, interventional case series. PARTICIPANTS One hundred consecutive keratoconus patients. INTERVENTION Deep anterior lamellar keratoplasty was performed using the big-bubble technique. During surgery, the cannula used for pneumatic dissection was inserted into the peripheral stroma and advanced as deep and far toward the center as believed adequate by the surgeon. Then, after retracting the cannula, AS OCT was performed. The cannula was placed back in position and creation of the big bubble was attempted. MAIN OUTCOME MEASURES Stromal depth reached with the cannula tip, success rate in achieving big-bubble formation, and complication rate. RESULTS Bubble formation was obtained in 70 of 100 eyes (70%). In all remaining eyes, the procedure was completed by manual deep lamellar dissection. The average depth reached by the cannula tip was 104.3±34.1 μm from the internal corneal surface; the mean value recorded in cases of successful big-bubble formation (90.4±27.7 μm) was statistically lower than that measured in failed procedures (136.7±24.2 μm). In 1 case, corneal perforation occurred during the insertion of the cannula and required conversion to penetrating keratoplasty (PK). In 8 eyes, small microperforations occurred during stromal excision but could be managed conservatively, avoiding conversion to PK. In 2 advanced cones, an incomplete bubble formation was obtained, necessitating manual peripheral stromal removal. CONCLUSIONS Successful big-bubble formation can be anticipated if pneumatic dissection is attempted at a sufficiently deep level. Although an ideal depth could not be defined, AS OCT allows objective evaluation of the depth reached by the cannula tip used for pneumatic dissection. The AS OCT findings may confirm the decision to proceed with air injection. It is possible that cannula repositioning based on the AS OCT depth may improve the success rate for big-bubble formation.

Complications of Sulcus-supported Intraocular Lenses with Iris Sutures, Implanted during Penetrating Keratoplasty after Intracapsular Cataract Extraction

In a retrospective study, the authors analyzed visual results and postoperative complications in a series of 14 consecutive patients who had undergone penetrating keratoplasty and implantation of a posterior chamber intraocular lens (PC IOL) in the absence of the posterior capsule. Seven patients suffered from aphakic bullous keratopathy and seven from pseudophakic bullous keratopathy. Postoperative follow-up was 7.6 months on the average. Best-corrected postoperative visual acuity was 20/60 or better in four cases and 20/200 or better in eight. Glaucoma was present before surgery in four eyes, which persisted in all cases and developed in four new cases. Results of gonioscopic examination showed the postoperative development of goniosynechiae in four eyes. Pseudophakodonesis of various extent was present in ten eyes. Preoperatively, cystoid macular edema was diagnosed angiographically in one case. It did not improve after surgery and was seen in three additional eyes postoperatively. Causes for postoperative visual acuity lower than 20/200 were cystoid macular edema in three cases, graft rejection in one case, central retinal scar in one case, and optic nerve atrophy in one case. A distortion of the pupil was seen in three eyes in miosis and in four additional eyes in mydriasis. Corneal thickness as well as anterior chamber depth were within normal limits. Fluorophotometric evaluation of the blood-aqueous barrier showed values comparable with those obtained after intracapsular cataract extraction and implantation of an iris-fixated IOL. Despite the relatively good visual results, the high postoperative incidence of cystoid macular edema and/or glaucoma may discourage the use of this technique.

Descemet-Stripping Automated Endothelial Keratoplasty for Congenital Hereditary Endothelial Dystrophy

OBJECTIVE To describe the results of Descemet-stripping automated endothelial keratoplasty (DSAEK) for congenital hereditary endothelial dystrophy (CHED). METHODS The medical records of all patients with CHED who underwent DSAEK at our institution were reviewed. A standard DSAEK was performed in all cases with the exception of the Descemet membrane not being removed in patients younger than 12 months. A thorough ophthalmic examination was performed preoperatively and at each postoperative visit in all patients. RESULTS Fifteen eyes of 8 patients with phakic eyes (4 male and 4 female) were included. The mean age was 9 years (range, 6 months to 30 years). The average follow-up was 15.9 months (range, 3 to 48 months). There were 4 cases of graft detachment, all of which were managed by rebubbling. All corneas were clear within 1 week after surgery. Two of the three infants (6 eyes) could fix and follow preoperatively, while all 3 could do so as early as 1 week following surgery on the second eye. In older patients (9 eyes), preoperative best-corrected visual acuity was 20/200 or less in 6 eyes. Postoperatively, 8 eyes achieved a best-corrected visual acuity of 20/40 or better. Endothelial cell loss (= 7 eyes) averaged 30.0% (range, 8.3% to 43.0%). CONCLUSIONS DSAEK performed in eyes with CHED allows rapid restoration of corneal clarity while minimizing intraoperative and postoperative complications. Our data suggest performing surgery at an earlier age, thus providing opportunity for improved visual development and potentially avoiding amblyopia.

Descemet membrane endothelial keratoplasty tissue preparation from donor corneas using a standardized submerged hydro-separation method.

PURPOSE To standardize a novel submerged hydro-separation technique for Descemet membrane endothelial keratoplasty (DMEK) graft preparation from donor corneal tissues. DESIGN Experimental study, laboratory investigation. METHODS SETTING The Veneto Eye Bank Foundation, Venice, Italy. STUDY POPULATION Fifty-four random human donor corneal tissues unsuitable for transplantation. INTERVENTION Donor corneas were laid in a sterile basin partially filled with tissue culture medium. A 25 gauge needle with 1 mL mounted syringe was filled with the tissue culture medium. The needle (with bevel up) was bent to 90 degrees and was inserted in the posterior cornea initiating beneath the trabecular meshwork. It was further advanced toward the midperiphery, ensuring that only the bevel was inserted, considering it as a threshold of insertion. The liquid was injected with a medium to high pressure into the posterior stroma or in the Descemet membrane-stroma interface to create the bubble. The tissues were preserved for 7 days in tissue culture medium at 31°C. Parametrical, physiological and histological analyses were carried out. MAIN OUTCOME MEASURES Larger-diameter tissue, no tissue wastage, reproducibility, and preshipment evaluation. RESULTS Complete detachment was achieved in all the cases without any tissue wastage. Average diameter of the excised graft was 10.80 (±0.28) mm and endothelial cell loss post preservation was 11.48%. Expression of tight junction protein and regular morphology was observed post preservation. No signs of cell apoptosis were seen. Histological analysis showed elimination of residual stroma in most of the cases. CONCLUSIONS The submerged hydro-separation method reduces tissue wastage. It allows preshipment evaluation, thus allowing a validated tissue to be transported from the eye banks to the surgeon. Because of the liquid interface, the peeling of the DMEK graft becomes easy for transplantation.

Sustained Gentamicin Release by Presoaked Medicated Bandage Contact Lenses

Current therapeutic regimens for external ocular infections require instillation of antibiotics up to every quarter of an hour in concentrations higher than those commercially available. As an alternative to topically applied gentamicin eye drops, the possibility of sustained gentamicin release by bandage contact lenses was investigated. Ten hydrogel bandage contact lenses (61.4% HEMA and 38.6% water content) were soaked overnight in a 0.5% solution of sterile, unpreserved, commercially available gentamicin, and fitted thereafter on ten eyes of healthy adult volunteers. Gentamicin concentrations in the tear film were determined 10, 30, and 60 minutes, and 4, 8, 24, 48, 72, and 96 hours after fitting, using agar diffusion bioassay. Bactericidal concentrations (greater than 1.6 micrograms/ml) were found up to 3 days after contact lens fitting in all subjects. No toxic topical or systemic effects were seen.