Intraoperative Microperforation Research Articles

Deep anterior lamellar keratoplasty in advanced keratoconus in children: A 4-year study

Purpose: The purpose of the study was to evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) in children and adolescents with advanced keratoconus (KC) at a tertiary eye care center in India. Design: This was a retrospective cross-sectional study. Methods: All cases of KC under the age group of 18 years, operated for DALK at a tertiary eye care center in South India, were evaluated from January 2018 to January 2022; outcome measures were best-corrected visual acuity (BCVA), graft clarity at final follow-up, and complications. Results: Of 27 eyes of 25 cases, 16 were male and 9 were female, with a mean age of presentation at 14.9 years. In stromal dissection technique, big bubble was attempted in 23 eyes and achieved in 20 eyes; manual dissection was done for the rest of the cases. Final BCVA varied from 0.1 to 0.6 logMAR units. Twenty-three eyes had excellent graft clarity at final follow-up. Complications noted in the study were intraoperative microperforation in four cases, postoperatively suture-related complications in three cases, and corneal graft rejection in one case. Conclusion: DALK in pediatric age group for advanced KC is an effective treatment option.

Outcomes of phaco-trabeculectomy versus phaco-viscocanalostomy for primary open angle glaucoma

PurposeThis study aimed to compare the intraocular pressure (IOP)-lowering effect and postoperative adverse effects of combined phacoemulsification and trabeculectomy (PT) and combined phacoemulsification and viscocanalostomy (PVC) in eyes with primary open-angle glaucoma (POAG). MethodsIn this prospective study, eighty-one consecutive patients (81 eyes) with POAG and cataract were enrolled. The eyes were randomly assigned to either the PT group (40 eyes) or the PVC group (41 eyes). The main outcomes included the success rate based on IOP and the evaluation of adverse effects during the 6-month follow-up period. The surgery was considered a complete success if the IOP was between 6 and 20 mmHg and reduced by ≥30% without glaucoma medications or additional surgery compared to the preoperative level. A qualified success was characterized by an IOP within the range of 6−20 mmHg and a 20−30% reduction in IOP achieved through the use of glaucoma medications. ResultsThe mean baseline IOP was 23.20 ± 7.94 mmHg in the PT group and 21.29 ± 6.81 mmHg in the PVC group (P = 0.249). At 6 months, the mean postoperative IOP in the PT and PVC groups were 13.50 ± 2.49, and 13.73 ± 1.70, respectively. There was no significant difference in mean IOP between the groups at any time (P > 0.05). At 6 months, 22 patients (55%) in the PT group and 22 patients (53.66%) in the PVC group achieved complete success. Nine eyes (22.50%) in the PT group and 10 eyes (24.39%) in the PVC group achieved qualified success. The other patients (9 eyes in each group) did not meet the criteria for at least a qualified success and were considered failures (P = 0.980). Intraoperative microperforation of Descemet's membrane occurred in 2 cases (15%) in the PVC group. Postoperative complications included 4 cases (10%) of shallow/flat anterior chamber, 1 case (2.5%) of choroidal effusion, and 1 case (2.5%) of aqueous misdirection in the PT group. The rate of these postoperative adverse effects was not significant between the two groups (P > 0.05). ConclusionsThere was no significant difference in IOP reduction between PT and PVC in patients with POAG. Furthermore, PVC is safe enough in these patients, compared to PT.

Hypotony-associated Complications After Deep Sclerectomy: Incidence, Risk Factors, and Long-term Outcomes.

Chronic hypotony is not uncommon following deep sclerectomy (DS), but only a minor proportion of patients develop hypotony-associated complications. Numerical hypotony does not affect the visual outcomes. This study identifies factors associated with hypotony. To investigate the incidence and risk factors of hypotony and hypotony-associated complications after DS. Retrospective cohort study of 1765 eyes (1385 patients) undergoing DS with or without cataract extraction between 2001 and 2020 in 2 UK centers. Chronic hypotony was defined as intraocular pressure (IOP) ≤5 mm Hg in ≥2 consecutive visits lasting >90 days or as any IOP ≤5 mm Hg associated with hypotony-related complications or requiring surgical intervention. Clinical hypotony was defined as the presence of: serous or hemorrhagic choroidal detachment, hypotony maculopathy, flat anterior chamber requiring reformation, decompression retinopathy. The incidence of hypotony was calculated with Kaplan-Meier statistics, and Cox regression was used to identify risk factors. The median (interquartile range) age and follow-up were 76 (67 to 82) years and 45.4 (20.9 to 79.8) months, respectively. The incidence (95% confidence interval) of chronic and clinical hypotony at 5 years was 13.4% (11.5%-15.3%) and 5.6% (4.3%-6.9%), respectively. Sixteen eyes (15.7%) with hypotony-associated complications had IOP >5 mm Hg. Male sex (hazard ratio [HR]: 1.89, P=0.018), non-Caucasian ethnicity (HR: 2.49, P=0.046), intraoperative bevacizumab (HR: 3.96, P=0.01), pigmentary glaucoma (HR: 3.59, P=0.048), previous vitreoretinal surgery (HR: 5.70, P=0.009), intraoperative microperforation (HR: 4.17, P<0.001) and macroperforation (HR: 20.76, P<0.001), and avascular bleb (HR: 1.80, P=0.036) were associated with clinical hypotony. Chronic hypotony is not uncommon following DS, but clinical hypotony is infrequent. Hypotony associated-complications can occur in eyes without statistical hypotony.

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.

Clinical outcome after air-assisted manual deep anterior lamellar keratoplasty for fungal keratitis poorly responsive to medical treatment.

PurposeFungal keratitis remains an important disorder because of difficulty in its diagnosis, and some patients do not respond to medical treatment using antifungal local and systemic agents. This study was carried out to determine the therapeutic value of air-assisted manual therapeutic deep anterior lamellar keratoplasty (TDALK) in the treatment of fungal keratitis not curable by antifungal chemotherapy.MethodsSeventeen patients (18 eyes) who were referred to Fukuoka University Hospital and treated surgically from January 2006 to April 2018, in whom a diagnosis of fungal keratitis was confirmed by typical clinical findings and microbiological or histological analysis of corneal specimens, and who were poorly responsive to topical and systemic antifungal medication, whereas the lesion had not resulted in corneal perforation, were enrolled in this study and were treated by air-assisted manual TDALK. Clinical outcomes including treatment course, therapeutic success rate, visual acuity outcomes and graft clarity rate were analyzed.ResultsThe most common pathogen was Fusarium, followed by Candida and Aspergillus. Beneficial therapeutic results (a clear or translucent graft) were achieved in 15 of 18 eyes (83%). There was no recurrence of infection and resulting visual acuity ≤0.15 logarithm of minimal angle of resolution unit was achieved in 15 eyes (83%). Intraoperative microperforation of Descemet’s membrane (DM) was not observed in any patients.ConclusionAir-assisted manual TDALK can be effective for treating severe fungal keratitis. In addition, air-assisted manual TDALK might be an alternative procedure to big-bubble DALK, because it can provide ambulatory vision and can preserve potentiality of vision with less risk of intraoperative perforation of DM.

Clinical Properties and Risk Factors for Descemet Membrane Folds After Deep Anterior Lamellar Keratoplasty in Patients With Keratoconus.

To report the clinical properties and risk factors for corneal Descemet membrane (DM) folds after deep anterior lamellar keratoplasty (DALK) in patients with keratoconus. This is a retrospective case-control study. Study participants-experimental group: 44 eyes with DM folds after DALK; control group: 135 eyes without DM folds after DALK. Forty eyes with DM folds were displayed as 1 or 2 translucent lines in the DM layer. Three eyes appeared as several arcuate shape lines, and 1 eye presented as a radial shape. DM folds impaired corrected visual acuity after DALK (P = 0.018). Age older than 20.5 years at surgery and disease duration longer than 5.5 years were independent risk factors for DM fold formation after DALK surgery (odds ratio 5.39, 95% confidence interval: 2.11-13.73, P < 0.001; 6.60, 95% confidence interval: 2.92-14.94, P < 0.001). Preoperative Kmean, Kmax, central corneal thickness, anterior chamber depth, sex, history of rigid gas permeable contact lens wearing, Vogt striae, stromal scar, and intraoperative microperforation had no influence on the occurrence of DM folds (P1 = 0.775, P2 = 0.896, P3 = 0.555, P4 = 0.182, P5 = 0.656, P6 = 0.237, P7 = 1.000, P8 = 0.587, and P9 = 0.798). DM folds impaired postoperative corrected visual acuity. The risk factors for DM folds included age older than 20.5 years and disease duration longer than 5.5 years.

Closure of microperforation during deep anterior lamellar keratoplasty with a corneal tissue fragment.

We present a case of intraoperative microperforation during routine deep anterior lamellar keratoplasty, managed with sealing the leak with the help of corneal tissue fragment and fibrin glue. Post operatively the graft was clear with complete closure of the perforation and without any further complications.

Avoiding big bubble complications: outcomes of layer-by-layer deep anterior lamellar keratoplasty in children

Background/aimsTo describe the visual and clinical outcomes of manual layer-by-layer deep anterior lamellar keratoplasty (DALK) in a paediatric population.MethodsThe charts of all children who underwent DALK surgery between January 2007...

Surgical outcome of deep anterior lamellar keratoplasty with air-assisted manual dissection for corneas with previous inflammation or fibrosis.

PURPOSE:To report our experience in air-assisted manual dissection deep anterior lamellar keratoplasty (DALK) for the treatment of corneal scar with previous inflammation and fibrosis.MATERIALS AND METHODS:We retrospectively reviewed the medical history of 21 patients (male:female = 13:8 mean age 41.9 years old) with corneal pathology from previous infection and inflammation. Trephination diameter ranged from 7.0 to 8.0 mm, and the graft was oversized by 0.25–0.50 mm. Debulking technique was performed to expose Descemet's membrane after filling stroma with air. Starting from postoperative 3 months, selective suture removal was performed to reduce corneal astigmatism.RESULTS:The mean follow-up period was 59.9 ± 19.8 (20–96) months. Intraoperative microperforation occurred in 2 eyes (9.5%); however, there was no shift to penetrating keratoplasty. Air-bubble tamponade was performed in 7 eyes (33.3%) for postoperative gapping of the graft. There were 2 failed grafts (9.5%) due to corneal ulcer while all the other grafts remained clear throughout follow-up. The mean preoperative best-corrected visual acuity (BCVA) was 1.84 ± 0.66 logMAR, which improved to 0.74 ± 0.63 (P < 0.01). The average sphere power was − 0.88 ± 3.88 diopter (D), average cylinder power 3.03 ± 1.46D, and average endothelial count 1877 ± 375 cells/mm2.CONCLUSION:In severe ocular surface diseases, big-bubble technique frequently failed to separate predescemtic plane; however, it effectively created air-filled stroma which was easier to remove. Although BCVA was suboptimal due to ocular surface disorders, graft survival and clarity rate is high, justifying the application of DALK in these cases.

Wet-Peeling Technique of Deep Anterior Lamellar Keratoplasty With Hypotonic Water and Blunt Dissection for Healed Hydrops.

To describe the surgical technique and outcomes of "wet-peeling" deep anterior lamellar keratoplasty (DALK) using sterile water and blunt dissection in cases with corneal scarring after healed corneal hydrops. Manual DALK using a "wet-peeling" technique was performed in 20 eyes of 20 consecutive patients with healed corneal hydrops between June 2011 and October 2013. Intraoperative microperforations were encountered in 2 (10%) cases. None of the cases required conversion to penetrating keratoplasty. There was significant improvement in mean best-corrected visual acuity at the end of 24 months postoperatively (0.99 ± 0.30 logMAR vs. 0.20 ± 0.11 logMAR; P < 0.001). The postoperative mean residual stromal bed thickness was 48.9 ± 5.9 μm, and mean central corneal thickness was 557.2 ± 50.3 μm. The mean endothelial density was 2021 ± 236 cells/mm at the final follow-up. Manual DALK using sterile water can be successfully performed in corneas with healed hydrops. Favorable visual outcomes may be attributed to thin residual bed thickness postoperatively.

Clinical evaluation of deep anterior lamellar keratoplasty using glycerol-cryopreserved corneal tissues for refractory herpetic stromal keratitis: An observational study.

The study aimed to evaluate the therapeutic effects of deep anterior lamellar keratoplasty (DALK) using glycerol-cryopreserved corneal tissues (GCCTs) in patients with refractive herpes simplex keratitis (HSK). This article was a retrospective, noncomparative, and interventional case series. Patients with HSK underwent DALK using GCCTs at Shanghai Tongji Hospital from 2012 to 2015. The best spectacle corrected visual acuity, recurrent inflammation, graft status, postoperative central graft thickness, and pre/postoperative complications were detected. The follow-up ranged from 24.4 ± 5.6 months (range: 16–38 months). Overall, the best spectacle corrected visual acuity was increased from HM/10 cm to 0.15 before surgery to 0.41 ± 0.14 (range: 0.1–0.8; P < 0.05) at 12 months postoperatively. Intraoperative microperforation occurred in 4 eyes (14.81%), and rejection episodes were encountered in 3 of 27 eyes (11.1%), and all of the eyes reversed. HSK recurred in 2 eyes (7.41%), 1 eye with repeated recurring HSK, and eventually led to perpetual corneal opacity and the patient refused a retransplantation. The mean entire corneal thickness was 0.519 ± 0.018 mm (range: 0.5–0.56 mm) and the mean graft thickness was 0.405 ± 0.033 mm (range: 0.35–0.47 mm) in the final follow-up. The DALK using GCCTs was proven to be an effective and safe therapy in treating refractory HSK.

The visual outcome and complications in deep anterior lamellar keratoplasty for keratoconus

Objective The aim of this study was to evaluate visual outcomes and complications of deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in patients with keratoconus. Background Keratoconus is a bilateral noninflammatory corneal thinning disorder leading to protrusion, distortion, and scarring of the cornea. Treatment options are glasses, hard contact lenses, cross-linking, intracorneal segment insertion, refractive surgery, or keratoplasty. DALK can be a better choice to manage cases of moderate and some cases of severe keratoconus without deep scarring and severe thinning. Participants and methods This interventional study was carried out on 47 eyes of 46 patients who presented with moderate to advanced keratoconus for DALK from December 2012 to June 2014 with a mean follow-up of 12 months. The best spectacle-corrected visual acuity, the refractive status, and intraoperative and postoperative complications were evaluated. Results Thirty-seven procedures (78.7%) were completed with big-bubble formation, and six patients (12.8%) required manual intrastromal dissection. Intraoperative microperforations occurred in four cases (8.5%). The mean preoperative uncorrected visual acuity was 0.036 ± 0.017 and the final best spectacle-corrected visual acuity at 1 year had a mean value of 0.38 ( P < 0.001). The postoperative mean spherical equivalent refractive error and astigmatism were − 4.9 ± 2.6 and − 3.9 ± 1.6 D, respectively. Main complications encountered included loosening of the stitches in 11 cases (23.4%), vascularization of the stitches in three cases (6.4%), double anterior chamber in two cases (4.3%), Urrets-Zavalia syndrome in one case (2.1%), stromal rejection in one case (2.1%), and suture abscess in one case (2.1%). Conclusion DALK using the big-bubble technique appears to be a safe and effective procedure in patients with keratoconus. Postoperative myopic astigmatism is observed in most of the cases.

Long-term comparison of full-bed deep anterior lamellar keratoplasty and penetrating keratoplasty in treating keratoconus

To compare postoperative outcomes of full-bed deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in treating keratoconus. Seventy-five eyes of 64 patients who received full-bed DALK and 52 eyes of 51 patients who received PK between June 2000 and August 2010 were included in this retrospective study. Full-bed DALK was performed using Yao's hooking-detaching technique. PK was performed using a standard technique. Intraoperative and postoperative complications, visual acuity, rejection, graft survival, endothelial cell density, corneal sensation recovery, and re-innervation were compared between the two groups. A best correct visual acuity of 0.5 or better was achieved in 90.7% of eyes after full-bed DALK and in 92.3% of eyes after PK (P=0.75). By the fifth postoperative year, graft endothelial cell loss reached 34.6% in the PK group vs. 13.9% in the full-bed DALK group (P<0.001). There were no statistical differences in corneal sensitivity recovery or corneal re-innervation between the groups (P>0.05). Intraoperative microperforation occurred in seven out of 75 (9.3%) eyes with a temporally postoperative double anterior chamber in two eyes in the full-bed DALK group. Postoperative complications in the PK vs. the full-bed DALK groups respectively were: rejection (7.7% vs. 0%, P=0.015), high intraocular pressure (IOP) (46.2% vs. 1.3%, P<0.001), secondary glaucoma (9.6% vs. 0%, P=0.006), complicated cataract (19.2% vs. 0%, P<0.001), and wound dehiscence (9.6% vs. 0%, P=0.006). Both full-bed DALK and PK can offer long-term satisfactory visual outcomes for keratoconus. Graft rejection, secondary glaucoma, complicated cataracts, and constant endothelial cell loss were observed in eyes only after PK.

Outcomes of deep anterior lamellar keratoplasty in keratoconic eyes with previous hydrops

AimTo evaluate outcomes of deep anterior lamellar keratoplasty (DALK) in keratoconic eyes with previous hydrops.MethodsIn this retrospective, non-comparative study, keratoconic eyes with previous hydrops that underwent DALK were included. DALK...

Pentacam-Based Big Bubble Deep Anterior Lamellar Keratoplasty in Patients with Keratoconus

To describe the clinical results of Pentacam-based big bubble deep anterior lamellar keratoplasty (DALK) to achieve an intended 90% depth of initial lamellar trephination. Fifty consecutive eyes of 50 patients with keratoconus, keratoglobus, and anterior stromal scars were included. DALK was performed with the big bubble technique using a 90% intended depth for initial lamellar trephination based on preoperative pachymetry by Pentacam. Main outcome measures were success of surgery, best spectacle-corrected visual acuity, endothelial cell count, refractive astigmatism at 12-month follow-up, and rate of intra- and postoperative complications. In 84% of the patients (n = 42), Pentacam-based big bubble DALK could be performed successfully. Successful big bubble formation could be achieved in 80% of the patients (n = 34). In case of macroperforation (n = 8), surgery was converted to standard penetrating keratoplasty representing a conversion rate of 16%. Intraoperative microperforation (n = 5) could be handled by an intracameral air injection at the end of operation with successful completion of the lamellar procedure. No allograft rejection was observed. Best spectacle-corrected visual acuity improved from 20/125 ± 20/160 preoperatively to 20/40 ± 20/80 at 12-month follow-up. Endothelial cell count was 2102 ± 318 cells per square millimeter preoperatively and 1735 ± 420 cells per square millimeter at 12-month follow-up. Refractive astigmatism was 7.09 ± 3.13 diopters preoperatively and decreased to 4.13 ± 2.41 diopters. Pentacam-based big bubble DALK using a 90% intended depth of initial lamellar trephination seems to be a safe and effective procedure for anterior corneal stromal disorders such as keratoconus. We suggest that Pentacam-based depth assessment allows for reliably deep initial preparation and may allow more successful bubble formation in DALK surgery.

Deep anterior lamellar keratoplasty for the management of iatrogenic keratectasia occurring after hexagonal keratotomy

Iatrogenic keratectasia has been reported subsequent to refractive surgery or trauma. Hexagonal keratotomy (HK) is a surgical incisional technique to correct hyperopia. A number of complications have been reported following this procedure, including irregular astigmatism, wound healing abnormalities and corneal ectasia. When visual acuity is poor because of ectasia or irregular astigmatism and contact lens fitting is not possible, penetrating or lamellar keratoplasty can be performed. Since incisions in refractive keratotomy are set at 90–95% depth of cornea, intraoperative microperforations are known to occur and lamellar keratoplasty may become difficult. We describe deep anterior lamellar keratoplasty (DALK) used to successfully manage keratectasia after HK. Pre DALK vision was 20/400 and post DALK vision was 20/30 two months after surgery. This report aims to show improved visual outcome in corneal ectasia secondary to HK. DALK can be a procedure of choice with proper case selection.

Deep Lamellar Keratoplasty After Resolution of Hydrops in Keratoconus

Deep anterior lamellar keratoplasty (DALK) using Anwar's big-bubble technique is contraindicated in cases of previous hydrops because of the risk of Descemet membrane (DM) rupture at the hydrops scar. Improved manual lamellar dissection techniques down to the deepest stromal layers now enable manual DALK surgery for previous hydrops with the possibility of obtaining good vision, as an alternative to conventional penetrating keratoplasty. Two retrospective case reports of manual DALK in patients with previous hydrops. A 12-year-old boy, with keratoconus and resolved hydrops in his left eye with deep stromal scarring, underwent bilateral manual DALK without baring of the DM. An intraoperative microperforation occurred in his left eye and was managed by intracameral injection of air to seal the perforation. Eleven months after his right DALK and 10 months after his left DALK, his right best spectacle-corrected visual acuity (BSCVA) was 20/20, and his left BSCVA was 20/25. The right cornea was clear, whereas the left cornea had minimal residual deep stromal scarring. Endothelial cell count by specular microscopy was 2611 cells per square millimeter in the right eye and 2193 cells per square millimeter in the left eye. A 28-year-old man, with keratoconus and resolved hydrops in his right eye with deep stromal scarring, underwent right manual DALK without baring of the DM. Nine months postoperatively, his right BSCVA was 20/30, and the graft was clear. Endothelial cell count by specular microscopy was 3148 cells per square millimeter in the right eye. DALK can be performed in patients with previous hydrops. A controlled deep manual dissection technique without baring the DM is advocated. Good final BSCVA can be achieved despite leaving a thin residual layer of the stroma unexcised.

Standardized big-bubble technique in deep anterior lamellar keratoplasty assisted by the femtosecond laser

We describe a variant of the big-bubble technique in deep anterior lamellar keratoplasty (DALK) assisted by the IntraLase femtosecond laser, which we call IntraBubble. The use of the 60 kHz IntraLase femtosecond laser allows dissection of the pre-Descemet-plane lamella to a predefined corneal depth and creation of a channel in the posterior stroma 50 μm above the endothelium into which a smooth cannula for air injection can be introduced. We lengthened the channel created by the laser using a pointed dissector. Eleven consecutive patients with keratoconus were treated, and all procedures were completed as DALK. The big bubble was achieved in 8 eyes (73%). In 3 cases (27%), intraoperative microperforations occurred and the procedures were completed with hand dissection without complications. This new application of femtosecond laser technology could lead to standardization of the big-bubble technique in DALK.

Randomized Comparison of the Intraocular Pressure–Lowering Effect of Phacoviscocanalostomy and Phacotrabeculectomy

To compare the intraocular pressure (IOP)-lowering effect of combined viscocanalostomy and phacoemulsification and combined trabeculectomy and phacoemulsification with mitomycin C in eyes with primary open-angle glaucoma. Prospective randomized 1-year trial. Forty consecutive patients (40 eyes) with primary open-angle glaucoma and cataract. Eyes were assigned randomly either to trabeculectomy with mitomycin C or to viscocanalostomy in combination with phacoemulsification and intraocular lens implantation. Success rate based on IOP. Mean baseline IOP was 24.0+/-2.0 mmHg in the viscocanalostomy group and 23.7+/-2.6 mmHg in the trabeculectomy group (P = 0.7). Mean postoperative IOP was 13.7+/-2.2 mmHg at 3 months, 14.8+/-3.3 mmHg at 6 months, and 14.9+/-3.0 mmHg at 12 months in the viscocanalostomy group and 12.1+/-4.0 mmHg at 3 months, 13.8+/-4.7 mmHg at 6 months, and 14.1+/-4.4 mmHg at 12 months in the trabeculectomy group. There was no significant difference in the mean IOP between the groups at any time. At 12 months, 17 patients (85%) in the viscocanalostomy group and 16 patients (80%) in the trabeculectomy group achieved an IOP of 20 mmHg or less without medication (P = 0.7). Complications included 2 cases (10%) of flat/shallow anterior chamber and 4 cases (20%) of hypotony in the trabeculectomy group, whereas intraoperative microperforation of Descemet's membrane occurred in 3 cases (15%) in the viscocanalostomy group. There was no significant difference in IOP reduction between viscocanalostomy and trabeculectomy with mitomycin C in combination with phacoemulsification and intraocular lens implantation in patients with primary open-angle glaucoma.

Clinical Outcomes After Deep Anterior Lamellar Keratoplasty Using the Big-bubble Technique in Patients With Keratoconus

To report clinical outcomes of deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in patients with keratoconus. Prospective noncomparative interventional study. Single hospital. Eighty-one unselected consecutive patients with moderate to advanced keratoconus intolerant to contact lenses and with poor spectacle-corrected visual acuity. DALK big-bubble technique. Intraoperative and postoperative complications, postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, corneal topography, and endothelial cell density. Seventy-eight procedures (96%) were completed as DALK. Big-bubble was achieved in 50 cases (64%); 28 (36%) required manual intrastromal dissection. Intraoperative microperforations occurred in 11 cases (13%). Baseline mean uncorrected visual acuity was 20/500 and 20/60 two years after surgery. Average preoperative BSCVA, was 20/100 and 20/30 at the end of follow-up. Final BSCVA was better in patients in whom big-bubble with exposure of the Descemet membrane was achieved (P < .05). Average keratometry and SD (standard deviation) refraction changed from 62.1 +/- 6.7 diopters and -10.76 +/- 5 diopters to 47.51 +/- 4.73 diopters and -1.81 +/- 3.2 diopters, respectively after surgery. Mean preoperative endothelial cell density was 2202.29 +/- 392.35 cells/mm(2) and 2034 +/- 438.39 cells/mm(2) two years after surgery. Two patients developed stromal rejection. The DALK big-bubble technique is a valuable treatment in patients with keratoconus. Visual outcome is comparable to standard penetrating keratoplasty (PK) when formation of big-bubble with exposure of the Descemet membrane (DM) was achieved. Clinically important graft-host interface developed in some cases after manual intrastromal dissection. Stromal rejection is a rare complication.