Post-penetrating Keratoplasty Glaucoma Research Articles

Clinical and surgical outcomes of glaucoma drainage device tube in ciliary sulcus versus anterior chamber in North Indian glaucoma patients.

To evaluate the outcome of glaucoma drainage device (GDD) insertion of tube through ciliary sulcus (CS) versus anterior chamber (AC) placement in the North Indian population. This retrospective comparative case series included 43 patients in CS group and 24 in AC group, who underwent GDD implantation, from March 2014 to February 2020. The main outcome measures were intraocular pressure (IOP), number of anti-glaucoma medications, best corrected visual acuity (BCVA), and complications. Sixty-seven eyes of 66 patients were included in study with mean follow-up of 25.04 months (range, 12-69 months) in the CS group and 17.4 months (range, 13-28 months) in the AC group. Preoperatively the two groups were similar except for postpenetrating keratoplasty glaucoma (PPKG) and pseudophakic patients, which were higher in the CS group (P < 0.05). Both groups showed statistically insignificant difference in postoperative IOP and BCVA at last follow-up (P = 0.173, P = 0.495, respectively). Postoperative complications were similar, except for corneal decompensation which was significantly higher in the AC group (P = 0.042). Our findings suggest that there was no statistically significant difference in mean IOP between the CS and AC groups at the last follow-up. CS placement of tube of GDD appears to be effective and safe technique. However, CS placement of tube resulted in lesser corneal decompensation and thus should be preferred in pseudophakic/aphakic patients, especially PPKG.

Incidence and risk factors for post-penetrating keratoplasty glaucoma.

Purpose:To carry out a prospective study to analyze the incidence and various preoperative, intraoperative, and postoperative risk factors for the development of PPKG.Methods:A total of 207 patients were analyzed prospectively, who were operated for penetrating keratoplasty (PK) in a tertiary eye care hospital between the time period of August 1, 2017 and February 28, 2018 and were followed up till the sixth month. Each patient was analyzed at every visit to determine the factors responsible for post-keratoplasty glaucoma.Results:Out of 207 eyes, post-PK glaucoma developed in 84 cases, which yielded an incidence of 41%. Incidence of PPKG (Post PK glaucoma) in various conditions was as follows: in repeat PK 62%, in perforated corneal ulcer 33%, in nonperforated corneal ulcer 29%, in corneal scar including adherent leukoma 37.2%, and in pseudophakic bullous keratopathy and aphakic bullous keratopathy, 14% and 80%, respectively. In age- and sex-adjusted multivariate analysis, the significant risk factors were age (P-value- 0.006), presence of PAS (P-value 0.001), and fellow eye glaucoma (P-value 0.04). Aphakia and combined surgery were not found to be significantConclusion:Our study recommends a meticulous examination of the fellow eye to assess the presence of glaucoma as it can increase the suspicion of glaucoma in the eye to be operated. The presence of PAS and age are important risk factors for developing PPKG. The risk of developing PPKG increases exponentially as the number of risk factors increases, but the presence of more than three risk factors does not add to the development of PPKG.

Pediatric Corneal Transplant Surgery: Challenges for Successful Outcome.

Visual rehabilitation of pediatric corneal blinds is a major challenge to corneal transplant surgeons. Penetrating keratoplasty (PKP) is the only way to restore vision and prevent irreversible blindness due to amblyopia in children. Performing penetrating corneal grafts in children poses difficulty in evaluation, technical difficulties during surgery and problems during follow-up. Younger children do not cooperate for proper slit-lamp examination and need to be examined under general anaesthesia. In addition, the complications encountered post PKP, including allograft rejection, post PKP astigmatism and post PKP glaucoma are more frequent in pediatric group as compared to adult recipients. Even after a successful graft, the child requires rigorous treatment for amblyopia. Parents need to be counselled before surgery and possible visual outcome and chances of obtaining clear graft should be discussed.

Outcome of penetrating keratoplasty in pseudophakic bullous keratopathy

Introduction: To study the outcome of penetrating keratoplasty in pseudophakic bullous keratopathy in terms of visual acuity, graft survival, complications and to identify prognostic factors. Materials and Methods: This was a hospital based, prospective interventional study, which included 24 eyes of 24 patients with pseudophakic bullous keratopathy who underwent penetrating keratoplasty with interrupted sutures by single corneal surgeon. Eyes with posterior chamber IOL were retained, eyes with anterior chamber IOL were explanted without IOL exchange. Cases were followed upto 6 months. The outcome was assessed in terms of visual acuity, graft survival, complications and post keratoplasty astigmatism as depicted on corneal topography at the end of 6 months. Results: Out of 24 cases, 5 cases were of regraft, 1 case was lost to follow up. Percentage of cases gaining visual acuity of 6/60 or more was 60.86%, clear grafts were 87%, graft failure was 13%. Incidence of post penetrating keratoplasty glaucoma was 30.43%. Astigmatism ranged from 6 to 13 dioptres as a difference between simulate keratometric value of steep meridian and flat meridian on corneal topography at 6 months. Conclusion: Penetrating keratoplasty in pseudophakic bullous keratopathy has good short term graft survival and moderate visual recovery. Retained posterior chamber IOL helped in better visual outcome. Glaucoma and immunological rejection were main causes for graft failure. Quality of donor tissue improves the outcome of penetrating keratoplasty. Keywords: Graft survival, Pseudophakic bullous keratopathy, Penetrating keratoplasty.

Comparison of Short-term Outcomes of Aurolab Aqueous Drainage Implant with Ahmed Glaucoma Valve in Post–Penetrating Keratoplasty Glaucoma: A Retrospective Follow-up Study at a Tertiary Care Center

Comparison of short-term outcomes of the Aurolab aqueous drainage implant (AADI) with the Ahmed glaucoma valve (AGV) in post-penetrating keratoplasty glaucoma (PPKG). Retrospective study design. We analyzed the data of patients who underwent glaucoma drainage device (GDD) implantation for PPKG between the time period of 2008 to 2017. A total of 57 eyes of 55 patients were included. Parameters including age, sex, corneal graft clarity, duration between the keratoplasty and glaucoma surgery, visual acuity (VA), intraocular pressure (IOP), the number of antiglaucoma drugs (topical and oral) before surgery, and type of GDD were studied. The patients were divided into 2 groups: group I, patients undergoing AADI implantation; and group II, patients undergoing AGV implantation. Patients with at least 6 months follow-up were included. The postoperative VA and IOP were analyzed on day 1 and at 1 week, 4 weeks, 6 weeks, 3 months, and 6 months. The success of GDD was defined as complete success (IOP > 5 mmHg or <21 mmHg without topical antiglaucoma drug) or qualified success (IOP > 5 mmHg or <21 mmHg with up to 2 topical antiglaucoma drugs). Failure was defined as IOP < 5 mmHg or >21 mmHg with or without antiglaucoma medication; IOP < 21 mmHg with 3or more topical medications or use of systemic medications irrespective of the IOP; loss of perception of light; and/or need for further glaucoma surgery. Nineteen eyes in group I (mean age= 40.16±16.36 years) and 38 eyes in group II (mean age= 56.61±19.35 years) were studied. The mean baseline IOP in group I and group II was not significantly different (28.63±11.21 vs. 30±14.61 mmHg, P= 0.72). Mean postoperative IOP at 6 months was not significantly different in the 2 groups (12.11±4.86 mmHg vs. 14.95±6.35 mmHg, P= 0.2). There was statistically significant fall in IOP at each visit compared to preoperative IOP in both the groups (P= 0.001), but there was no significant difference between the 2 groups at any time point (P > 0.05). At 6 months overall success rate was 84.21% in both groups (P= 1.00), though the complete success was slightly higher in group II, which was nonsignificant (31.58% vs. 39.47%, P= 0.56). There was no significant difference between baseline and final VA in either group. Both AADI and AGV are equally effective in controlling IOP in post-penetrating glaucoma. The AADI, being a cost-effective implant, may be more suitable for developing countries.

Graft Survival after Penetrating Keratoplasty in Cases of Trabeculectomy versus Ahmed Valve Implant.

Purpose To compare the corneal graft survival rates after penetrating keratoplasty (PKP) in cases of post-PKP glaucoma managed by either trabeculectomy with mitomycin C or Ahmed glaucoma valve (AGV). Methods This study was a retrospective interventional comparative study that included 40 eyes of 40 patients. The included patients had undergone previous PKP for anterior segment reconstruction after microbial or fungal keratitis, chemical burns, trauma, or perforated corneal ulcer. Post-PKP glaucoma was managed surgically by either trabeculectomy with mitomycin C (group 1) or Ahmed glaucoma valve (group 2). Results The first group (n=20) had undergone trabeculectomy with MMC, and the second group (n=20) had undergone AGV implantation. Regarding BCVA, there was no statistically significant difference between the 2 groups. Mean IOP was significantly lower in the AGV group at 6 months, 12 months, and 24 months (p=0.001). Mean IOP at 24 months dropped significantly from preglaucoma surgery levels in both groups (p=0.001). Rejection episodes occurred in 2 eyes (10%) of the trabeculectomy group versus 8 eyes (40%) in the AGV group (p=0.028). In the trabeculectomy group, corneal graft failure occurred in 1 (5%), 3 (15%), and 6 (30%) eyes at 6 months, 12 months, and 24 months, respectively. In the AGV group, corneal graft failure occurred in 2 (10%), 5 (25%), and 10 (50%) eyes at 6 months, 12 months, and 24 months, respectively. The mean time to failure in the trabeculectomy group was 12.33 ± 5.60 months versus 11.90 ± 5.70 months in the AGV group (p=0.027). Conclusion Managing postpenetrating keratoplasty glaucoma could be bothersome especially in complex cases. Ahmed glaucoma valve implant controls the intraocular pressure more effectively than trabeculectomy with mitomycin C. However, Ahmed glaucoma valve can result in higher rates of corneal graft failure in a shorter duration of time. This trial is registered with PACTR201712002861391 on 21 Dec 2017.

Incidence and risk factors for postkeratoplasty glaucoma in tertiary care center, India.

BACKGROUND:Glaucoma is the leading cause of blindness after penetrating keratoplasty (PK) and its early diagnosis and management is mandatory to salvage the graft.AIMS:This study aimed to evaluate the incidence and risk factors for post penetrating keratoplasty glaucoma (PKG).METHODS:Data of 155 eyes of 155 patients were reviewed retrospectively who underwent PK from March 2013 to February 2016. Data were analyzed from recipient records for recipient age, sex, indications, type of PK, lens status, recipient graft size or any additional procedure. Detailed ophthalmological examination was recorded for all cases including best corrected visual acuity (BCVA), slit lamp examination, intraocular pressure (IOP) by applanation tonometry or tonopen, central corneal thickness (CCT) and gonioscopy. IOP measurement records were reviewed at each visit of one week, two weeks,one, three and six months and if IOP was elevated (>22 mmHg) medical management was initiated. Uncontrolled IOP with antiglaucoma medication (AGM) required surgical management.RESULTS:Overall incidence of raised IOP after PK was 32.25%. Increase in IOP post PK was reported mainly in 32 (64%) among age group >40 years. Raised IOP showed significant association with age group, indications of PK, recipient size and CCT (P value 0.00, 0.01, 0.00, 0.00) respectively. Two weeks after PK 46 (29.67%) patients reported an increase in IOP ,47(30.32 %) after 1 months, 33 (21.29%) at 3 months and 30 (19.35%) at 6 months. In 11 (39.28%) cases cataract was major long term complication seen in PKG cases. 35 (70%) cases of PKG were treated medically and 15 (30%) patients required surgical treatment.CONCLUSION:Subjects with age group >40 years, corneal opacity, increased recepient size and increased CCT are risk factors for PKG. IOP monitoring in early post operative period especially one month after PK is mandatory to avoid graft failure due to PKG which is difficult to diagnose otherwise.

Incidence and risk factors for post-penetrating keratoplasty glaucoma: A systematic review and meta-analysis.

ObjectivesTo establish the incidence and risk factors for post penetrating keratoplasty glaucoma (PKKG).MethodsStudies published between 1947 and 2016 regarding penetrating keratoplasty (PK) were identified using an electronic search and reviewed. For search purpose, PKKG was defined as ocular hypertension (> 21mmHg) after PK. The incidence and risk factors of PKKG were extracted for all studies. Pooled incidence, odd ratios (ORs) and 95% confidence intervals (CIs) were calculated.ResultsThirty studies reporting on 27146 patients were included in the analysis of the incidence and risk factors for PKKG. Exact PKKG definitions used in the literature could be classified in to three subgroups: I, ocular hypertension (> 21mmHg) after PK; II, I plus > 4 weeks medical treatment required; III, II plus treatment escalation among patients with preexisting glaucoma. Overall (Definition I) pooled incidence in all studies was 21.5% (95% CI 17.8%, 25.7%). The incidence varied according to different definitions. The highest incidence value was found when only studies using Goldmann tonometer were included (22.5%), while the lowest incidence was found when a strict definition was used and steroid-induced PPKG was excluded (12.1%). The incidence was higher in patients with preexisting glaucoma, bullous keratopathy (BK), aphakia, pseudophakia, failed graft, and surgical indication of trauma. A triple procedure (combined PK with extra capsular cataract extraction and intraocular lens implantation) was not identified as being associated with the increased risk for PKKG.ConclusionsThe overall pooled incidence of PKKG was 21.5%, but it varied according to the criteria used to define the presence of PPKG. Strong risk factors for PKKG included preexisting glaucoma and aphakia, while modest predictors included pseudophakia, regrafting, and preoperative diagnosis like BK and trauma. There may not be sufficient evidence to identify a significant association between a triple procedure and PKKG.

Post penetrating keratoplasty glaucoma – A review

Glaucoma following penetrating keratoplasty remains a challenge for the treating ophthalmologist. Its frequent occurrence, difficult diagnosis and recalcitrant nature coupled with the propensity to cause irreversible visual loss makes it essential to identify the problem early and manage it effectively. A careful pre-operative assessment along with appropriate intra-operative measures can help to reduce the chances of developing glaucoma in the post-operative period. Wherever indicated, prompt therapy should be initiated to lower intraocular pressure and salvage vision. Effective management of post-operative keratoplasty glaucoma remains an enigma with no single therapy being suited for all cases. One has to weigh the risks and benefits of the anti-glaucoma drugs on the corneal graft. However, it should be kept in mind that although there is a potential option for a graft exchange, vision lost from glaucomatous optic nerve damage cannot be recovered. This review aims at highlighting the magnitude of the problem, assessing the risk factors that predispose to post-penetrating keratoplasty glaucoma along with the methodology for its diagnosis and management.

Preoperative risk factors and incidence of glaucoma after penetrating keratoplasty

Background: Glaucoma following penetrating keratoplasty is one of the serious complications due to its frequency of occurrence, difficulty in diagnosis and management, risk of graft failure and irreversible visual loss due to optic nerve damage. The incidence of glaucoma after keratoplasty varies from 9% to 31% in the early postoperative period and from 18 to 35% in the late postoperative period. The aetiology of this disorder is multifactorial and the clear understanding of the various mechanisms that operate during different time frames following penetrating keratoplasty is essential to chalk out the appropriate management algorithms. Methods: Prospective analysis of 100 consecutive eyes which underwent penetrating keratoplasty during the period from September 2009 to December 2010 at Bangalore West Lions super speciality eye hospital was done. The patients were followed up for a minimum period of 9 months. Results: Out of 100 patients mean age distribution was 47 ± 11 years. Of the 100 patients male 68% and 32 female (32%). Out of 100 eyes 38% of them had vision &lt;6/60, 36% of them had vision between 6//36-6/18 and 26% of them between 6/18-6/6. Raised intraocular pressure was found in 15 out of 100 eyes. Mean raise in intraocular pressure was 29 mmHg ± 1.5 mmHg. Out of 15 patients 4 were steroid responders. Mean time of diagnosis of raised intraocular pressure was 5 ± 9.5 months. Pseudophakic Bullous Keratopathy (PBK) in 5 (33.3%) patients, aphakic bullous keratopathy (ABK) in 3 (20%) patients, graft rejection in 2 (13.3%) patients and one each patient (6.7%) of corneal scar, adherent leucoma, chemical injury and congenital hereditary endothelial dystrophy. Aphakic group was at higher risk compared to the other groups and there was not much difference between the phakic and the pseudophakic group. Conclusions: Post penetrating keratoplasty glaucoma continues to be a clinical problem that can be sight threatening in its clinical outcome. It is mandatory that intraocular pressure is monitored on a regular basis. Recognition of the risk factors namely, indications, graft size, lenticular status &amp; associated surgical procedure with penetrating keratoplasty would help in early diagnosis of post penetrating keratoplasty glaucoma. Most of these cases are amenable to medical management.

Glaucoma in penetrating keratoplasty: risk factors, management and outcome

Glaucoma is a leading cause for graft failure. This retrospective study analyzes the risk factors, graft status, and treatment modalities in patients with post-penetrating keratoplasty glaucoma. A retrospective analysis of case records of 1,848 penetrating keratoplasties carried out between 2000 and 2005 was performed. A total of 160 patients (160 eyes) with post-penetrating keratoplasty glaucoma were included; 112 cases were primary grafts, 48 repeated grafts. The assessment included the pre-operative history of corneal disease and glaucoma, the lens status, and the anesthesiological techniques. Furthermore, the response to anti-glaucoma treatment, graft failure, and endothelial cell loss was evaluated. The incidence of post-penetrating keratoplasty glaucoma was 8.7 % (160/1,848). Preoperative glaucoma was the most important risk factor (62/160). Half of the patients (81 patients) responded to medical therapy (51 %) and the other half of patients (79 patients) to surgical therapy (49 %); of the latter, filtering surgery were performed in 16 %, cyclodestructive procedures in 66 % and both in 16 %. One patient received a glaucoma implant and cyclodestructive procedures (1 %). After 24 months, clear grafts were achieved in 94 eyes (59 %). Visual acuity after 24 months of 20/200 (logMAR 1.0) or better was achieved in 77 eyes (46 %) and of 20/50 (logMAR 0.4) in 33 eyes (21 %). Careful and ongoing observation of IOP, especially in the first year after PK, is recommended for patients after penetrating keratoplasty and prompt treatment of IOP elevation when indicated. Early filtering surgery with a better outcome than other surgery procedures should be preferred if medical treatment is not sufficient. Despite anti-glaucoma therapy, good visual outcome can remain beyond expectations despite a clear graft. While there is a potential option for graft exchange, damage to the optic nerve from end-stage glaucoma leads immutably to visual loss.

Effect of 0.5 mm larger donor corneal size on intraocular pressure following penetrating keratoplasty

Glaucoma can develop after penetrating keratoplasty resulting in irreversible loss of vision. The incidence of post-penetrating keratoplasty glaucoma varies from 31% in the early postoperative period to 29% after three months. Various factors are responsible for the rise of intraocular pressure (IOP). This study was carried out to evaluate the effect of 0.5 mm larger donor corneal size on IOP following penetrating keratoplasty. Patients were divided into two groups: group I was phakic and group II consisted of aphakic and pseudophakic patients. The same surgical technique was used for obtaining and suturing the donor graft. The viscoelastics and the postoperative regime also remained the same in all cases. IOP was measured by the rebound tonometer. The incidence of postoperative raised IOP in the first seven days in the phakic group was found to range from 16 mmHg to 25 mmHg and IOP in the aphakic/pseudophakic group ranged from 16 mmHg to 42 mmHg. The IOP in the phakic group after three weeks of surgery was around 12.3 mmHg and that in the pseudophakic/aphakic group was 14.8 mmHg-16.2 mmHg. In aphakic patients, IOP was controlled in the first six months with eyedrops Timolol 0.5% and tablet acetazolamide which was given only for short periods. IOP settled to < 12 mmHg with timolol 0.5% after six months. In the pseudophakic patients, IOP became normal by six months. These were inclusive of patients who had undergone anterior reconstruction and/or vitrectomy. The study proves that keeping the donor corneal size 0.5 mm larger does not affect IOP and that aphakia itself is a factor responsible for rise of IOP due to anterior chamber angle compression.

Ahmed glaucoma valve in post-penetrating-keratoplasty glaucoma: A critically evaluated prospective clinical study

Aim:The aim was to evaluate the outcome of Ahmed glaucoma valve (AGV) in post-penetrating-keratoplasty glaucoma (PKPG). Materials and Methods:In this prospective study, 20 eyes of 20 adult patients with post-PKPG with intraocular pressure (IOP) >21 mmHg, on two or more antiglaucoma medications, underwent AG (model FP7) implantation and were followed up for a minimum of 6 months. Absolute success was defined as 5 <IOP <21 mmHg and qualified success as 5 <IOP <21 mmHg with medications or minor procedures.Results:The mean IOP decreased from 42.95 ± 10.24 to 17.69 ± 3.64 mmHg (P <0.001) and the use of medications dropped from 2.92 to 0.39 (P <0.001) after AGV implantation. The absolute success was achieved in 11 eyes and qualified success in 9. There was no significant change in best corrected visual acuity, graft clarity, or graft thickness. Six device-related complications occurred after AGV implantations which were successfully managed with medical or minor surgical therapy.Conclusions:Postkeratoplasty refractory glaucoma managed by AGV implantation revealed a satisfactory outcome up to 6 months of follow-up.

Evaluation of Ex-PRESS Mini Glaucoma Shunt Implantation in Refractory Postpenetrating Keratoplasty Glaucoma

To evaluate the intraocular pressure (IOP) control and graft survival after Ex-PRESS mini glaucoma shunt implantation in refractory postpenetrating keratoplasty glaucoma. The study included postpenetrating keratoplasty glaucoma cases unresponsive to medical antiglaucomatous therapy in whom 15 Ex-PRESS mini glaucoma shunt implantation was carried out. All glaucoma shunt implantations were performed in a separate session after penetrating keratoplasty. Nine operations were performed under general anesthesia and 6 were performed under local anesthesia. Topical antibiotherapy and topical corticosteroids were used during the postoperative first month. Mean age of the study population was 37.4 years (range: 10 to 80 y). IOP decreased from 41.46 mm Hg (range: 26 to 80 mm Hg) to 12.06 mm Hg (range: 8 to 25 mm Hg) over a mean follow-up of 12.2 months (range: 8 to 19 mo) (P<0.001; Wilcoxon signed rank test). IOP was below 21 mm Hg in 14 of 15 eyes (93.3%) with or without antiglaucomatous drugs. Complete success (IOP<21 mm Hg without medication) rate was 86.6%. Average number of antiglaucomatous drug usage decreased from 3.20 (range: 2 to 4) preoperatively to 0.26 postoperatively (range: 0 to 3) (P<0.001; Wilcoxon signed rank test). In 93.3% of the cases, the decrease in IOP was 30% or above postoperatively. After Ex-PRESS implantation, clear grafts remained clear while edematous grafts became clearer due to IOP decrease. Neither biomicroscopy nor pachymetry showed worsening of preoperatively opaque grafts. Ex-PRESS mini glaucoma shunt implantation may be an effective procedure for refractory postpenetrating keratoplasty glaucoma with acceptable graft failure rates in short term.

Ultrasound Biomicroscopy in Opaque Grafts With Post-Penetrating Keratoplasty Glaucoma

To evaluate the anterior segment in opaque grafts with post-penetrating keratoplasty glaucoma (PPKG) by using ultrasound biomicroscopy (UBM). An observational clinical case series of patients with opaque corneal grafts with PPKG who underwent UBM examination of the anterior chamber is reported. Indication for keratoplasty, lens status, intraocular pressure at the time of presentation, and the time of diagnosis of glaucoma were noted. Examination included slit-lamp biomicroscopy, posterior-segment ultrasound evaluation, and UBM evaluation of the anterior segment. Thirty-one eyes of 31 patients with PPKG were recruited into the study. The mean intraocular pressure was 35.5 +/- 5.8 mm Hg (range, 26-52 mm Hg). The mean time of follow-up after penetrating keratoplasty was 6.97 +/- 2.98 months (range, 2-16 months). Of the 31 patients, 11 had undergone penetrating keratoplasty for therapeutic purposes (infectious keratitis), whereas the remaining 20 had undergone keratoplasty for optical reasons. Fourteen (45.1%) patients were pseudophakic, 13 (41.9%) were aphakic, and 4 (12.9%) were phakic. The types of synechiae noted on the UBM included peripheral anterior synechiae in 30/31 (96.7%) eyes, synechiae at the graft-host junction in 13/31 (41.93%) eyes, both peripheral anterior synechiae and graft-host junction synechiae in 12/31 (38.7%) eyes, central iridocorneal synechiae in 6/31 (19.3%) eyes, and intraocular lens iris synechiae in 3/31 (9.6%) eyes. Secondary angle closure caused by anterior synechiae formation is one of the important causes of PPKG in eyes with opaque grafts. UBM serves as a useful tool for anterior-segment evaluation in such cases and can help in planning the site for glaucoma filtering surgeries and drainage devices.

Post-penetrating keratoplasty glaucoma

Post-penetrating keratoplasty (post-PK) glaucoma is an important cause of irreversible visual loss and graft failure. The etiology for this disorder is multifactorial, and with the use of new diagnostic equipment, it is now possible to elucidate the exact pathophysiology of this condition. A clear understanding of the various mechanisms that operate during different time frames following PK is essential to chalk out the appropriate management algorithms. The various issues with regard to its management, including the putative risk factors, intraocular pressure (IOP) assessment post-PK, difficulties in monitoring with regard to the visual fields and optic nerve evaluation, are discussed. A step-wise approach to management starting from the medical management to surgery with and without metabolites and the various cycloablative procedures in cases of failed filtering procedures and excessive perilimbal scarring is presented. Finally, the important issue of minimizing the incidence of glaucoma following PK, especially through the use of oversized grafts and iris tightening procedures in the form of concomitant iridoplasty are emphasized. It is important to weigh the risk-benefit ratio of any modality used in the treatment of this condition as procedures aimed at IOP reduction, namely trabeculectomy with antimetabolites, and glaucoma drainage devices can trigger graft rejection, whereas cyclodestructive procedures can not only cause graft failure but also precipitate phthisis bulbi. Watchful expectancy and optimal time of intervention can salvage both graft and vision in this challenging condition.

Long-term results of transscleral Nd:YAG cyclophotocoagulation for refractory glaucoma postpenetrating keratoplasty.

To determine the effects of noncontact transscleral Nd:YAG cyclophotocoagulation (NCTY) in the treatment of refractory glaucoma postpenetrating keratoplasty (PKP) with respect to intraocular pressure (IOP), corneal graft survival, and reduction of glaucoma medications. The records of all patients treated with NCTY for refractory glaucoma after PKP at the authors' institution over an 11-year interval were reviewed. The LASAG noncontact Nd:YAG laser (Lasag AG; Thun, Switzerland) was used. Approximately 40 laser applications were delivered per eye. Visual acuity, IOP, glaucoma medications, and corneal graft clarity were evaluated. Fifty-two eyes met the inclusion criterion. The mean pretreatment IOP was 38.7+/-11.9 mm Hg. The mean posttreatment IOP was 15.8+/-9.7 mm Hg. From life table analysis, the probability of having a posttreatment IOP of 21 mm Hg or less with or without medication was 70% at 1 year and 63% at 5 years. The probability of a graft remaining clear was 79% at 1 year and 56% at 5 years. In 85% of patients the visual acuity remained stable, in 11% the visual acuity improved, and in 4% the visual acuity deteriorated after treatment. One patient developed hypotony. Twenty patients (36.5%) were able to discontinue one or more glaucoma medications posttreatment. In this group of patients with PKP glaucoma, NCTY effectively lowered IOP over the long term, with 36.5% of patients discontinuing one or more glaucoma medications. There was, however, a significant incidence of graft failure at 5 years.

Implante de Schocket modificado para o controle do glaucoma pós-ceratoplastia penetrante

RESUMO Nove olhos de 9 pacientes portadores de glaucoma pos-ceratoplas tia penetrante foram submetidos a cirurgia com implante de Scho cket modificado. Seis olhos era afacos. A media das pre-intraoculares pre-operat6rias era 38.2 mmHg ± 5.6, com variacao de 32 a 46 mmHg. A media das pressoes intraoculares pos-operatorias foi 14.6 mmHg ± 2.4. O tempo medio de seguimento foi 10.6 meses ± 3.0, com variacao de 6 a 15 meses. Todos os olhos tiveram a pressao intraocular igual ou menor que 20 mmHg, 6 dos quais (66,6%) com medicacao complementar. Num olho, houve obstrucao do tubo por humor vitreo. Este olho desenvolveu, 6 meses apos, descolamento de retina. Nao houve, em ne nhum dos olhos, rejeicao do enxerto.