Graft endothelium and thickness after penetrating keratoplasty, comparing mechanical and excimer laser trephination: a prospective randomised study

Purpose: To assess the impact of nonmechanical trephination on the graft endothelium and thickness after penetrating keratoplasty (PK). Methods: Inclusion criteria for this prospective, randomised, cross-sectional, clinical study were: (1) Treatment between October 1992 and December 1997; (2) one surgeon (G.O.H.N.); (3) primary central PK; (4) Fuchs’ dystrophy (diameter 7.5/7.6 mm) or keratoconus (diameter 8.0/8.1 mm); (5) graft oversize 0.1 mm; (6) no previous intraocular surgery; (7) 16-bite double-running diagonal suture. In 179 patients (mean age 51±18 years), PK was performed using either the 193-nm Meditec MEL60 excimer laser (”Excimer”) along metal masks with eight ”orientation teeth/notches” (53 keratoconus, 35 Fuchs’ dystrophy) or motor trephination with the Mikrokeratron (Geuder) (”Control”: 53 keratoconus, 38 Fuchs’ dystrophy). For donor trephination from the epithelial side an artificial anterior chamber was used in both groups. In 27% of the excimer and 29% of the control group a triple procedure was performed. Specular microscopy (EM-1000, Tomey) and pachymetry (SP-2000, Tomey) were performed before removal of the first suture (0.4±0.2 years postoperatively), before (1.1±0.4 years) and after (1.7±0.6 years) removal of the second suture but before any additional surgical intervention. Results: Endothelial cell count: Neither ”two-sutures-in” (1953±426/1804±385 cells/mm², p=0.13), ”one-suture-in” (1629±439/1765±440 cells/mm², p=0.27), nor ”all-sutures-out” (1259±493/1294±532 cells/mm², p=0.83) differed significantly between Excimer and Control. Graft thickness: Neither ”two-sutures-in” (527±58/524±16 μm, p=0.89), ”one-suture-in” (537±72/551±40 μm, p=0.86), nor ”all-sutures-out” (576±53/565±62 μm, p=0.38) differed significantly between Excimer and Control. Cell count and corneal thickness were not significantly different comparing Fuchs’ dystrophy and keratoconus or comparing PK only and triple procedures. Graft thickness and endothelial cell count correlated highly significantly inversely with ”all sutures out” (P<0.0001). Conclusions: Excimer laser trephination from the epithelial side using an artificial anterior chamber in donors seems to have no disadvantages concerning the graft endothelium after PK. Endothelial cell loss was not increased in eyes with Fuchs’ dystrophy compared with keratoconus or after triple procedures compared with PK only. Received: 7 February 2000 Revised: 7 September 2000 Accepted: 20 September 2000     

Impact of increased intraocular pressure on long-term corneal endothelial cell density after penetrating keratoplasty

PURPOSE: Besides immunological graft rejection, persistently increased intraocular pressure (IOP) is among the most important causes for graft failure after penetrating keratoplasty (PK). The purpose of this study was to assess the longitudinal development of IOP after PK and to investigate possible correlations with corneal endothelial cell density. METHODS: This longitudinal prospective study included 209 eyes after PK with a complete follow-up at 3 months, 6 months, before first suture removal (16 +/- 5 months) and after complete suture removal (21 +/- 5 months). At each examination, IOP was measured by Goldmann applanation tonometry. Endothelial cell density was assessed by specular microscopy (EM 1100, Tomey). The indications for PK were 48% keratoconus, 34% Fuchs' dystrophy, 5.4% stromal dystrophies, 8.6% secondary bullous keratopathy and 4% corneal scars. An iridotomy was performed routinely during PK. The postoperative treatment with topical steroids was standardized. RESULTS: Preoperatively, the mean IOP was 13.6 +/- 2.9 mm Hg with increased IOP (>21 mm Hg) in 2.0% of eyes. After 3 months, the incidence of increased IOP (24.5 +/- 4.6 mm Hg) was highest (6.7%) and decreased thereafter to 3.0% after complete suture removal. No patients showed IOP higher than 30 mm Hg. A persistently increased IOP for more than 3 months was seen in 2% of patients. At 3 months postoperatively, the mean endothelial cell density was 1,977 +/- 496/mm(2) and did not decrease significantly (p > 0.05) until 6 months (1,771 +/- 507 cells/mm(2)). At the end of the follow-up period, the mean endothelial cell density was significantly reduced (1,347 +/- 501 cells/mm(2)). There was no significant correlation between IOP and mean endothelial cell density at any postoperative examination stage (p > 0.24). Patients with persistently increased IOP for more than 3 months did not have significantly different endothelial cell densities in comparison with those without increased IOP. CONCLUSION: From 6 months after PK, the incidence of increased IOP was not higher than the preoperative level. Mild to moderate temporary IOP elevations after PK do not seem to affect the endothelial cell density of the graft until complete suture removal. Further long-term studies are necessary to assess the clinical relevance of these observations.     

Immunological graft reactions after penetrating keratoplasty - A prospective randomized trial comparing corneal excimer laser and motor trephination]

BACKGROUND AND PURPOSE: Nonmechanical trephination has been established as an advantageous procedure in penetrating keratoplasty (PK) for avascular corneal diseases and has been performed successfully in more than 1000 eyes at our institution. The purpose of this study was to compare incidence, type and reversibility of immunological graft reactions after mechanical and nonmechanical trephination for PK. PATIENTS AND METHODS: As part of a prospective randomized clinical trial 179 eyes of 76 females and 103 males were included, that had primary central PK without previous intraocular surgery between 10/1992 and 12/1997 for Fuchs' dystrophy (diameter 7.5 mm, n=73) or keratoconus (8.0 mm, n=106). The recipient and donor trephinations were performed from the epithelial side using either a motor trephine (Microkeratron, Geuder, n=91) or an 193-nm excimer laser (MEL60, Aesculap-Meditec, 1.5 x 1.5 mm spot mode, 16 - 24 mJ/pulse, repetition rate 25/s) along round metal masks with 8 "orientation teeth/notches" (n=88). As a routine, donor oversize was 0.1 mm. 128 patients (72 %) had PK only, 51 patients had simultaneous cataract extraction and PC-IOL implantation (triple procedure). Wound closure was achieved using a 16-bite double running diagonal suture by one surgeon (G.O.H.N.). In 53 % of procedures short-term-preserved donor tissue, in 47 % organ-cultured tissue was used. The mean patient/donor age was 51 +/- 17/57 +/- 19 years with nonmechanical trephination and 50 +/- 19/58 +/- 20 years with mechanical trephination. Incidence, type and reversibility of endothelial immunologic graft reactions were recorded continuously by clinical follow-up in an outpatient service with cornea specialization (after 6 weeks, then every 3 months until after suture removal, then every half year). RESULTS: During a mean follow-up of 40 +/- 15 months, 7.3 % of eyes developed an immunological endothelial graft reaction. Acute diffuse (5.6 %) were more frequent than chronic focal reactions (1.7 %). Only 1.7 % of grafts became irreversibly cloudy. More than 80 % of all graft reactions occurred later than one year (on average 23 +/- 13 months) after PK. Neither incidence (p=0.82, Chi square test) nor cumulative 3-year-rate of immunological graft reactions (p=0.91, LogRank test) differed significantly comparing nonmechanical (6.8 % or 7.3 %) and mechanical (7.7 % or 5.6 %) trephination. In eyes with keratoconus (6.6 %, 16 +/- 8 months) graft reactions did not occur more frequently (p=0.68) but earlier (p=0.02) than in eyes with Fuchs' dystrophy (8.2 %, 31 +/- 11 months). Donor age, post-mortem-time and preservation period did not significantly affect the rate of graft reactions in our study setting. CONCLUSIONS: Besides well-established optical advantages, nonmechanical trephination using the excimer laser seems to have no immunologic drawbacks in contrast to conventional mechanical trephination. Donor parameters appear to have no major impact on the incidence of graft reactions after non-high-risk PK. Rather, an adequate postoperative therapy with topical steroids, an informed patients' compliance, a consequent long-term follow-up in a clinical out-patient service with corneal specialization and a good education of and cooperation with the referring ophthalmologists are of utmost importance for the clear corneal graft in the long run.     

Corneal dimensions in various types of corneal dystrophies and their effect on penetrating keratoplasty

PURPOSE: To achieve a high optical performance and a low rate of immunologic graft reactions after penetrating keratoplasty (PK) an optimal graft outline has to be chosen. The purpose of this study was to compare the corneal dimensions of patients with various types of corneal dystrophies to normal control eyes. METHODS: In patients with keratoconus (n = 117), Fuchs' (n = 100), granular (n = 28), lattice (n = 26) and macular corneal dystrophy (n = 25) and normal controls subjects (n = 93) standardized slit lamp photographs of the cornea were taken. Using a computerized planimeter (SummaSketch III, Summagraphics Corp., Seymour, USA) 13 x 18-cm color prints (total magnification x12) were assessed morphometrically. RESULTS: On average, the maximal and the minimal diameter of corneas in patients with macular dystrophy (12.3 mm/10.6 mm) and normal controls (12.1 mm/10.5 mm) were significantly smaller (p < 0.02) than in patients with keratoconus (12.6 mm/10.9 mm), granular (12.7 mm/10.8 mm) and lattice dystrophy (12.8 mm/10.8 mm), but significantly larger (p < 0.02) than in patients with Fuchs' dystrophy (11.9 mm/10.4 mm). In Fuchs' dystrophy the corneas were significantly (p < 0.0001) more elliptical than in all other dystrophies and controls. The rotation of the maximal diameter from the horizontal ranged from 36 degrees nasal inferior to 44 degrees nasal superior and did not differ between dystrophies and controls. CONCLUSIONS: In patients with keratoconus, lattice and granular dystrophy larger grafts may be considered to improve the optical performance without promoting the risk of immunologic graft reactions after PK. As a rule, we use 8.0/8.1 mm (recipient/donor) for keratoconus and 7.5/7.6 mm for Fuchs' dystrophy. However, the graft diameter has to be determined individually in each single eye immediately before trephination.     

The evaluation of the usefulness of phacotrabeculectomy as the only surgery for glaucoma and cataract patients

PURPOSE: To evaluate IOP changes after phacotrabeculectomy. MATERIAL AND METHODS: 24 glaucoma patients (27 eyes) with coexistence of cataract. Age: 56-79 years. Mean IOP level before surgery: 23.2 +/- 2.4 mm Hg. In all cases phacotrabeculectomy was performed. Follow-up ranged from 3 to 12 months. RESULTS: IOP decrease after surgery was achieved: mean decrease 7.1 +/- 2.3 mm Hg after 3 months and 5.5 +/- 2.4 mm Hg, and 4.1 +/- 2.1 mm Hg after 6 and 12 months, respectively. CONCLUSION: Phacotrabeculectomy combines all advantages of phacoemulsification and creates perspective for IOP normalization.     

Long-term outcomes of Ahmed glaucoma valve implantation in refractory glaucomas

PURPOSE: To evaluate the long-term efficacy of intraocular pressure (IOP) reduction and complications of Ahmed glaucoma valve (AGV) implantation (New World Medical, Inc, Rancho Cucamonga, California, USA) in refractory glaucoma. DESIGN: Retrospective cohort study. METHODS: Retrospective medical records from 64 patients (78 eyes) with refractory glaucoma who underwent AGV implantation with a minimum of three years of follow-up were reviewed. Data regarding age, gender, race, eye laterality, specific glaucoma diagnosis, best-corrected visual acuity (BCVA), number of medications, IOP, visual fields, surgical complications, and follow-up interval were collected from all visits and were analyzed. The primary outcome measure was cumulative probability of success defined as IOP of less than 21 mm Hg and of 5 mm Hg or more with a minimum of 15% reduction from baseline IOP, without additional glaucoma surgery or loss of light perception. Secondary outcomes included IOP and number of medications at three, six, 12, 24, 36, 48, and 60 months after surgery, surgical complications, and final BCVA. RESULTS: The cumulative probability of success was 80% and 49% at one and five years, respectively. IOP was reduced from a mean of 30.4 +/- 10.7 mm Hg to 17.0 +/- 5.0 mm Hg at 12 months and 15.9 +/- 3.0 mm Hg at 60 months (P < .001). The number of medications decreased from 3.2 +/- 1.0 medications at baseline to 1.6 +/- 0.4 at 12 months and 2.1 +/- 0.2 at 60 months (P < .001). Prior glaucoma surgery and the silicone type of AGV were statistically significant risk factors for failure (P < .001). CONCLUSIONS: Approximately 50% of single-plate AGV implantations in refractory glaucoma were considered successful after five years of follow-up. Prior glaucoma surgery was a statistically significant risk factor for failure.     

Mid- and long-term results after trabeculectomy in patients with juvenile and late-juvenile open-angle glaucoma

BACKGROUND: To determine success rate of trabeculotomy in patients with juvenile and late-juvenile glaucoma in a retrospective study. PATIENTS AND METHODS: 46 eyes of 41 juvenile glaucoma-patients (24 female, 17 male) were submitted to trabeculotomy during the period of 1980-1997. Patients age at the time of surgery was 30.2 +/- 10.5 years (11-49 years, median 21 years). Follow-up time was 35 +/- 46 months (1-155 months). RESULTS: Median preoperative visual acuity was 1.0 (range 0.002 to 1.25), postoperative visual acuity at the end of the follow up period was 0.8 (median) with a range from 0.002 to 1.2. In all patients preoperative intraocular pressure was elevated and a glaucomatous configuration of the optic disc was noticed. Preoperative intraocular pressure (IOP) ranged from 30.5 +/- 13.2 mm Hg, after surgery IOP was 16.2 +/- 5 mm Hg. Mean decrease of the IOP postoperatively was 54.4%. In 37% of the eyes IOP was lower than 23 mm Hg without additional medication, in 47% of the eyes IOP was lower than 23 mm Hg with additional medication. In 8 eyes additional antiglaucoma-surgery was necessary. After a follow-up time of 60 months 81% of the patients (n = 37 eyes) had an IOP below 23 mm Hg, after 120 months in 80% of the patients (n = 29 eyes) IOP was below 23 mm Hg. CONCLUSION: The success rate of trabeculotomy (defined as the ability to lower intraocular pressure lower than 23 mm Hg with or without antiglaucoma medication) in our patients is 84%. After second operation, success rate is 89%. Trabeculotomy for patients with juvenile open angle glaucoma is a safe procedure and avoids problems and complications of filtering procedures.     

Combined phacoemulsification and goniotrephination in primary open-angle glaucoma and pseudoexfoliation glaucoma - a retrospective analysis

BACKGROUND: During the last few years combined cataract and glaucoma surgery is an established method to control intraocular pressure (IOP) and visual rehabilitation in patients with cataract and glaucoma. Despite this, there are currently only few data concerning the results of combined surgery for primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEXG). PATIENTS AND METHODS: To study the course of PEXG and POAG with respect to IOP regulation and visual acuity, 100 eyes with POAG (72 patients) and 22 with PEXG (19 patients) were evaluated which underwent a combined phacoemulsification and goniotrephination between 1993 and 1997. All patients had no glaucoma or other ocular surgery before. The mean follow up after operation was 39.5 (range 16 - 72) months. RESULTS: The mean preoperative IOP in PEXG (31.8 +/- 10.3 mm Hg) was significantly higher than in the POAG group (25.3 +/- 6.4 mm Hg) (p=0.0004). At follow up IOP decreased to 16.7 +/- 2.8 mm Hg (POAG) and 15.1 +/- 4.0 mm Hg (PEXG) (p < 0.0001). The absolute IOP lowering effect was significantly better for PEXG than for POAG (p=0.0003). All patients received medical treatment before surgery, whereas at follow up 59.0 % (POAG) and 81.8 % (PEXG) were untreated. The median preoperative visual acuity for the POAG was 0.32 (PEXG 0.25), visual outcome 0,63 (PEXG 0.5). CONCLUSION: The combined cataract and glaucoma surgery is a successful method of IOP control and visual rehabilitation. It seems that there is a tendency for a better efficiency and an untreated IOP regulation after surgery for PEXG. Thereby early surgical intervention could be an advantage for this glaucoma entity.     

Surgical outcomes of trabeculotomy combined with sinusotomy for juvenile glaucoma

PURPOSE: To evaluate the outcome of trabeculotomy combined with sinusotomy for juvenile glaucoma. METHODS: We studied 16 patients (25 eyes) (age range, 11-50 years) with juvenile glaucoma for a minimum follow-up period of 1 year. We performed combined trabeculotomy and sinusotomy surgery in 13 juvenile glaucoma patients (18 eyes), and trabeculotomy alone in 6 patients (7 eyes). RESULTS: The intraocular pressure (IOP) of the combined surgery group was 29.8 +/- 7.8 mm Hg before surgery and 15.6 +/- 3.0 mm Hg 1 year after surgery. The IOP of the trabeculotomy-alone group was 29.1 +/- 6.4 mm Hg before surgery and 15.4 +/- 2.4 mm Hg 1 year after surgery. A postoperative IOP spike that was higher than the preoperative IOP was recorded in 2 eyes of the combined surgery group and in 2 eyes of the trabeculotomy group. The combined surgery group consisted of 7 eyes with a previously failed glaucoma surgery, and 11 eyes having a first glaucoma surgery. The postoperative IOP in these 11 eyes was 15.5 +/- 2.8 mm Hg. CONCLUSION: Trabeculotomy is very effective in lowering the IOP in patients with juvenile glaucoma. Sinusotomy does not play an important role in tension control.     

Corneal endothelial cell loss after nonmechanical penetrating keratoplasty depends on diagnosis: a regression analysis

PURPOSE: To assess the impact of diagnosis on corneal endothelial cell loss after nonmechanical penetrating keratoplasty (PK) with regression models.METHODS: Five hundred eighty-nine eyes [273 with keratoconus (group I; PK only), 187 with Fuchs' endothelial dystrophy (group II; 77 PK only and 110 triple procedures) and 129 with bullous keratopathy (group III; 115 pseudophakic and 14 aphakic eyes)] were included in this prospective study. The time course of the endothelial cell density after PK was assessed by specular microscopy. Endothelial cell density was analyzed in cross-sectional fashion at 6 and 24 months follow-up and in longitudinal manner (follow-up 2.4+/-1.8 years) with linear and exponential regression models (minimizing the residuum between observed and predicted endothelial cell count). Donor age, post-mortem time, storage time and ratio of organ-cultured to short-term-preserved donor corneas did not differ significantly between groups of patients.RESULTS:In a cross section, endothelial cell density in group I / group II / group III decreased from 1,959+/-499 / 1,524+/-528 / 1,526+/-670 cells/mm(2)to 1,617+/-553 / 1,222+/-520 / 1,063+/-384 cells/mm(2) (P=0.06 / 0.04 / 0.005). Endothelial cell count was significantly higher in group I than in group II (P=0.048) and significantly higher in group II than in group III (P=0.01) at 24 months. In the linear regression model, cell count decreased in group I / group II / group III by 136+/-465 / 241+/-374 / 421+/-484 cells annually. In the exponential regression model, cell count decreased in group I / group II / group III by 2.9+/-28.0% / 11.2+/-21.8% / 19.3+/-29.4% annually. Cell loss was highly significantly lower in group I than in group II ( P<0.0001) and highly significantly lower in group II than in group III (P<0.0001).CONCLUSION:Endothelial cell loss seems to be least pronounced after PK in keratoconus (2.9%), followed by Fuchs' dystrophy (11.2%) and bullous keratopathy (19.3%). These differences between diagnoses indicate migration of endothelial cells along a density gradient after PK.     

Evaluation of the hypertensive phase after insertion of the Ahmed Glaucoma Valve

PURPOSE: To investigate the postoperative hypertensive phase (HP) in patients undergoing glaucoma drainage implant surgery. DESIGN: Interventional case series. METHODS: A retrospective chart review of 156 consecutive eyes (139 patients) who underwent placement of an Ahmed Glaucoma Valve (AGV) with a follow-up of >or=3 months was performed. Main outcome measures were occurrence and resolution of the HP and intraocular pressure (IOP) control. The HP was defined as IOP > 21 mm Hg during the first 3 months after surgery. Resolution of the HP was defined as an IOP < 22 mm Hg and an IOP reduction of 3 mm Hg with the same or fewer number of glaucoma medications. RESULTS: An HP was observed in 88 eyes (56%). It occurred after a mean of 5.0 weeks (median, 4 weeks; range, 1-13 weeks) with an average (+/- standard deviation) peak IOP of 30.1 (+/- 7.5) mm Hg. Resolution of the HP occurred in 19 of 68 eyes (28%) with available data. Eyes with an HP had a higher mean IOP and needed more medications 6 to 12 months after surgery than eyes without an HP (17.2 +/- 5.6 vs 14.3 +/- 5.8 mm Hg; P =.012 and 1.7 +/- 1.2 vs 0.3 +/- 0.6 medications; P <.001, respectively). CONCLUSION: A hypertensive phase occurs frequently after implantation of the AGV. However, it resolves in only a minority of eyes. The majority of eyes with an HP have no significant improvement of IOP control and continue to require the same number of glaucoma medications as they did during the HP.     

Frequency and risk factors of intraocular pressure increase after penetrating keratoplasty

PURPOSE: The aim of this study was to evaluate the incidence, risk factors and management of glaucoma following penetrating keratoplasty (PK) and to check for possible correlations with the indication for PK. PATIENTS AND METHODS: 534 eyes of 483 patients (age 54.7 +/- 19.8 years), that had undergone PK from 1989 to 1999 were retrospectively analyzed. The mean follow-up was 2.7 +/- 1.8 years. According to the type of surgical procedure patients were classified in 5 groups: group 1) PK only (n = 291); group 2) PK combined with extracapsular cataract extraction and intraocular lens (IOL) implantation (n = 124); group 3) PK combined with secundary IOL-implantation or IOL-change (n = 32); group 4) PK only after previous cataract surgery (n = 55) and group 5) Cataract surgery after PK (n = 32). The trephination was performed from the epithelial side in donor and recipient either by nonmechanical trephination with the 193 nm excimer laser (n = 444) or mechanical trephination (n = 90). An iridotomy was performed routinely during PK. The postoperative treatment with topical steroids was standardized. RESULTS: Preoperatively, glaucoma was diagnosed in 3.2% for all patients with groups 3 und 4 showing a significantly larger number of glaucomatous eyes (15.6% and 18.9%). Most of the mild early intraocular pressure elevations in group 1 (3.4%) and group 2 (3.0%) were controlled after 6 months (0.5% and 1.1%). Groups 3 and 4 showed most frequently increased intraocular pressure and/or antiglaucomatous treatment (21.4% and 18.7%) six weeks postoperatively. Patients in all groups showed no higher prevalence of persistent glaucoma from six months postoperatively than preoperatively throughout the follow-up period. Again groups 3 and 4 presented the largest number of persistent glaucoma. In most eyes the IOP was controlled by topical antiglaucomatous treatment. Serious forms seen in 2 patients with anterior synechiae caused by anterior chamber lens required several filtering surgeries or pars plicata diathermy, respectively. One patient with pseudoexfoliation syndrome required laser trabeculoplasty. The so-called "Urrets-Zavalia syndrome" was seen in none of the patients. CONCLUSION: The development of increased intraocular pressure after PK varied with the indication for keratoplasty. Postkeratoplasty glaucoma seems to be strongly associated with preexisting anterior synechiae and/or simultaneous anterior chamber lens implant removal. Intraoperative iridotomy can prevent the development of acute angle closure glaucoma after keratoplasty.     

Predictive donor factors for chronic endothelial cell loss after nonmechanical penetrating keratoplasty in a regression model

PURPOSE: To assess the diagnosis-based impact of donor parameters and trephination diameter as predictive factors on corneal endothelial cell density with an exponential regression model after nonmechanical penetrating keratoplasty (PK). METHODS: Six hundred thirty-one eyes [291 keratoconus (group I, trephination diameter 8.0 mm); 202 Fuchs' dystrophies (group II, trephination diameter 7.5 mm)-84 PK only (IIa) and 118 triple procedures (IIb); and 138 pseudophakic bullous keratopathies (group III, trephination diameter 6.5-8.0 mm)] were included in this retrospective study. The time course of the endothelial cell density (specular microscope EM 1100, Tomey, Erlangen) after PK was assessed. Endothelial cell density was analyzed in a longitudinal manner considering at least three valid postoperative cell counts (follow-up 29+/-17 months) with an exponential regression model (minimizing the residuum between observed and predicted endothelial cell count). The following potentially predictive parameters were assessed: donor age (DA), post-mortem time (PM), storage time (ST) and trephination diameter (group III). RESULTS: In the exponential regression model endothelial cell count decreased in I/II/III by 3.1+/-24.2% / 12.6+/-20.2% (IIa: 8.9+/-17.3%, IIb: 14.8+/-22.0%) / 18.7+/-27.3% annually. PM ( P=0.16 / P=0.10 / P=0.25) and DA ( P=0.20, / P=0.12 / P=0.16) did not correlate with the cell loss, but ST ( P=0.04 / P=0.04 / P=0.02) showed a mild correlation, especially in short-term-stored corneas. In group III the trephination diameter ( P=0.01) correlated inversely with the cell loss. Between short-term-preserved and organ-cultured donor corneas there was no statistically significant difference in the cell loss in any group. CONCLUSIONS: The post-mortem time and the donor age is not associated with a chronic endothelial cell loss after keratoplasty, whereas a long storage time may exaggerate the endothelial cell loss. Between short-term-preserved and organ-cultured donor corneas there was no difference in the time gradient. In bullous keratopathy patients a larger trephination size reduces the chronic endothelial cell loss.     

The effect of corneal thickness on intraocular pressure measurement in patients with corneal pathology

BACKGROUND/AIM: To compare intraocular pressure (IOP) measurements taken by the Goldmann applanation tonometer, the Tono-Pen and the ocular blood flow pneumotonometer in eyes with varying central corneal thickness (CCT) due to penetrating keratoplasty (PK), keratoconus (KC), and Fuchs' endothelial dystrophy (FED). METHODS: IOP was measured with the Goldmann applanation tonometer, Tono-Pen XL, and OBF pneumotonometer in 127 eyes with the following corneal abnormalities. There were 56 eyes that had undergone PK, 37 eyes with KC, and 34 eyes with FED. CCT was measured using an ultrasound pachymeter after IOP determinations had been made. RESULTS: Mean IOP measurements in all three patient groups were significantly higher when measured by OBF pneumotonometer. Linear regression analysis showed that patients with FED had a significant increase in IOP with increasing CCT of 0.18 mm Hg/10 microm using the Goldmann tonometer, 0.15 mm Hg/10 microm with the Tono-Pen, and 0.26 mm Hg/10 microm with the OBF pneumotonometer. In patients with KC and after PK, linear regression analysis did not show a significant effect of CCT on IOP. A multivariate linear regression model controlling for age, sex, graft size, and patient group, showed that the effect of CCT on IOP for Tono-Pen (0.13 mm Hg/10 microm CCT) and Goldmann (0.14 mm Hg/10 microm CCT) were significantly lower than for the OBF pneumotonometer (0.26 mm Hg/10 microm CCT). CONCLUSIONS: This study found that mean IOP measurements using the OBF pneumotonometer were significantly higher than those made using the Goldmann applanation tonometer or Tono-Pen in eyes with a variety of cornel pathologies. The OBF pneumotonometer was found to be most affected by variation in CCT. For all three instruments, the relation between IOP and CCT depended on the corneal pathology and was greatest for FED.     

Intraocular pressure after phacoemulsification with posterior chamber lens implantation in open-angle glaucoma

BACKGROUND: To evaluate changes in intraocular pressure (IOP) after phacoemulsification (Phaco) with posterior chamber lens (PC IOL) implantation in eyes with primary open-angle glaucoma (POAG) at least 2 years after surgery. PATIENTS AND METHODS: 19 eyes of 13 POAG patients who underwent uneventful clear cornea Phaco with PC IOL implantation and with follow-up of at least 2 years after surgery were included in this retrospective study. None of them had previous intraocular surgery or argon laser trabeculoplasty. RESULTS: The average preoperative IOP was 16.9 +/- 2.02 mm Hg. The average follow-up of was 36 +/- 11.8 months. 1 week after surgery a significant decrease in average IOP was observed (13.8 +/- 3.0 mm Hg; P = 0.000). 1 and 4 months after surgery IOP was still significantly lower than preoperatively. 8 months after surgery IOP significantly increased to 15.9 mm Hg (+/- 2.9 mm Hg; P = 0.022) with respect to 1 week postoperatively, but then again significantly decreased to 15.5 mm Hg (+/- 2.6 mm Hg; P = 0.020) 1 year after surgery and stayed approximately the same at 2 and 3 years after surgery. After 4 years the average IOP was 15.0 mm Hg (+/- 3.1 mm Hg; P = 0.216), that was statistically insignificant because of the small number of patients. In 79% (15 eyes) of our cases medical antiglaucoma treatment was unchanged, in 21% (4 eyes) the therapy was reduced. CONCLUSIONS: Uneventful Phaco with PC IOL implantation in good medically controlled POAG eyes was associated with a statistically significant long-term decrease in IOP, allowing the reduction of postoperative antiglaucoma medications in more than 20% of the eyes.     

Surgical outcomes of combined phacoemulsification and glaucoma drainage implant surgery for Asian patients with refractory glaucoma with cataract

PURPOSE: To examine the safety and efficacy of combined phacoemulsification and glaucoma drainage implant surgery in providing reduction of intraocular pressure (IOP) and visual rehabilitation in eyes with refractory glaucoma and cataract. DESIGN: Interventional case series. METHODS: A retrospective chart review was performed on all subjects who underwent combined phacoemulsification with intraocular lens implantation and glaucoma drainage implant surgery by a single surgeon at the National University Hospital, Singapore. The implants used were the 185 mm2 Ahmed glaucoma valve and the 350 mm2 Baerveldt glaucoma implant. In terms of IOP, a complete success was defined as IOP of between 6 to 21 mm Hg without medication, qualified success as IOP between 6 to 21 mm Hg with one or more medication, and failure as a sustained IOP of >21 mm Hg or <6 mm Hg with or without one or more medication on two or more visits. RESULTS: A total of 32 combined phacoemulsification and glaucoma implant surgeries in 32 patients was performed. All patients were of Asian origin, and the mean age was 58 +/- 16 years (range, 20-78 years). The Baerveldt glaucoma implant and Ahmed glaucoma valve implant were inserted in 16 eyes each. With a mean follow-up of 13 +/- 5 months (range 6 to 22 months), IOP was reduced from a mean of 28.0 +/- 11.5 mm Hg to 15.2 +/- 6.0 mm Hg postoperatively (P <.0001), whereas the number of antiglaucoma medications decreased from a mean of 2.4 +/- 1.4 to.3 +/-.7 (P <.0001) at last follow-up. Overall, there were 24 eyes (75%) that were classified as complete successes, 4 eyes (12.5%) that were qualified successes, and 4 eyes that failed (12.5%). Twenty-three eyes (72%) had improvement of visual acuity, while only one eye had a loss of more than 1 line of Snellen acuity. There was no case that encountered an intraoperative complication, and postoperative complications occurred in 12 eyes (38%), the most common of which was hypotony (in six eyes, 19%). CONCLUSION: For subjects with refractory glaucoma and cataract, combined phacoemulsification and glaucoma drainage implant surgery provide good visual rehabilitation and control of IOP, with low incidence of complications.     

Combined endoscopic erbium:YAG laser goniopuncture and cataract surgery

PURPOSE: To study the safety and efficacy of endoscopic erbium:YAG (Er:YAG) laser goniopuncture combined with cataract surgery to treat glaucoma. SETTING: Department of Ophthalmology, Albert-Ludwigs-University Freiburg, Freiburg, Germany, and Institute of Applied Physics, University of Bern, Bern, Switzerland. METHODS: In this nonrandominized clinical trial, 20 eyes of 20 patients with cataract and glaucoma were treated by combined phacoemulsification and Er:YAG goniopuncture. The primary study endpoints were intraocular pressure (IOP), visual acuity, and number of antiglaucoma drugs 1 year after surgery. Two- and 3-year postoperative data were also measured. This prospective treatment arm was compared to a retrospective inclusion-matched control group treated by cataract surgery alone. RESULTS: The mean IOP dropped by 30% (23.5 mm Hg +/- 3.9 [SD] to 16.3 +/- 2.7 mm Hg) after 12 months in the laser-treated group (P<.0001) and by 9% (19.8 +/- 1.3 mm Hg to 18.1 +/- 1.8 mm Hg) in the control group (P =.12). After 3 years, the mean IOP in the laser group was 15.0 +/- 2.0 mm Hg. The mean number of antiglaucoma drugs needed decreased from 1.6 +/- 0.9 to 0.5 +/- 0.8 in the laser group (P<.0001) and from 1.0 +/- 0.9 to 0.8 +/- 0.9 in the control group (P =.21). Anterior chamber hemorrhage occurred in 12 eyes after laser treatment and resolved within 72 hours in all but 1 patient who was on warfarin sodium (Coumadin) therapy. There were no cases of hypotony in either group. CONCLUSIONS: Endoscopic Er:YAG laser goniopuncture was a successful adjunct to cataract surgery in glaucoma patients. Sustained IOP reduction was achieved with few postoperative complications.     

小梁切除联合羊膜植入和巩膜瓣松解缝线术治疗难治性青光眼

目的　探讨小梁切除联合羊膜植入和巩膜瓣松解缝线术治疗难治性青光眼的疗效。方法　对完成追踪观察的 5 8例 (6 7只眼 )难治性青光眼患者施行小梁切除术 ,术中巩膜瓣下及结膜瓣下植入新鲜或贮存羊膜 ,联合应用巩膜瓣松解缝线术控制房水渗漏量。结果　术后随访 5～ 38个月 ,平均 19 5个月 ,其中≥ 12个月者占 79 1%。术后 12个月时 ,新生血管性青光眼的眼压由术前 (43 86± 7 12 )mmHg(1mmHg=0 133kPa)降至 (19 6 3± 2 5 7)mmHg(t=4 96 ,P <0 0 0 1) ,人工晶状体植入术后青光眼的眼压由术前 (40 31± 4 79)mmHg降至 (18 0 9± 2 2 1)mmHg(t=3 5 4 ,P <0 0 5 ) ,无晶状体性青光眼的眼压由术前 (37 94± 5 6 3)mmHg降至 (2 0 14± 3 15 )mmHg (t=5 12 ,P <0 0 5 ) ,青少年型青光眼的眼压由术前 (32 4 8± 3 98)mmHg降至 (16 5 4± 1 84 )mmHg(t=4 2 3,P <0 0 1) ,葡萄膜炎性青光眼的眼压由术前 (36 0 1± 4 13)mmHg降至 (18 11± 3 4 0 )mmHg(t=4 4 7,P <0 0 1) ,滤过性手术失败的青光眼眼压由术前 (34 4 3± 5 2 8)mmHg降至 (18 31± 1 5 2 )mmHg(t=2 0 5 ,P <0 0 5 ) ;患者手术前、后眼压比较 ,差异均有显著意义。功能性滤过泡形成率为 80 6 %。无排斥反应和严重并发症。结论     

Seven-year follow-up of combined cataract extraction and viscocanalostomy

PURPOSE: To investigate the long-term success and complications of phacoemulsification combined with viscocanalostomy (phacoviscocanalostomy) in eyes with coexisting cataract and medically uncontrolled glaucoma. SETTING: Department of Ophthalmology, Warrington Hospital, Warrington, United Kingdom. METHODS: A prospective nonrandomized study evaluated 165 consecutive eyes (114 patients) that had phacoviscocanalostomy. The main outcome measures were intraocular pressure (IOP), visual acuity, requirement for topical antiglaucoma medication, and the presence or absence of drainage blebs or bleb complications. RESULTS: The mean follow-up was 38.7 months +/- 19.3 (SD) (range 12 to 90 months). There was a statistically significant decrease in IOP, from 24.1 +/- 5.1 mm Hg preoperatively to 13.8 +/- 8.1 mm Hg 1 day after surgery (P<.001), 16.0 +/- 4.1 mm Hg at 5 years (P<.001), and at all evaluations to the last follow-up. The mean number of medications per eye decreased significantly from 2.5 +/- 0.9 before surgery to 0.1 +/- 0.5 at last follow-up (P<.001). At the final follow-up, IOP was reduced by 33.2% (16.2 mm Hg versus 24.1 mm Hg). Complete success, defined as an IOP reduction of more than 30% from preoperative level without medications, was achieved in 48.5% of eyes, with 42% of eyes having an IOP of less than 16 mm Hg. The percentage fall in IOP was linearly related to the preoperative IOP level (P<.001). No eye developed a trabeculectomy-type bleb, and there were no bleb-related complications. CONCLUSIONS: Phacoviscocanalostomy was safe and effective for the management of eyes with coexisting cataract and medically uncontrolled glaucoma. It provided a stable and sustained reduction in IOP with a minimum requirement for topical medication.     

Temporal contrast sensitivity using full-field flicker test (Erlangen flicker test) in patients after penetrating keratoplasty

BACKGROUND: The purpose of this study was to evaluate the feasibility of temporal contrast sensitivity testing using full-field flicker stimulation in patients after penetrating keratoplasty (PK) and to assess whether this method is influenced by postoperative corneal topographic changes. METHODS: Forty-five patients (age 46.5+/-14.2, median 47 years) who had undergone PK and 194 age-matched controls were included in this study. The postoperative interval was 11.8+/-10.2 months (median 9 months). Patients with pre-existing glaucoma or any postoperative intraocular pressure elevation were excluded. The indications for PK were keratoconus in 54% of cases, Fuchs' dystrophy in 38% and stromal dystrophies in 8%. Temporal contrast sensitivity was determined with sinusoidal flickering light (37.1 Hz) of constant mean photopic luminance (10 cd/m(2)) presented in a full-field bowl with an increasing threshold strategy. RESULTS: Mean temporal contrast sensitivity did not differ between patients after PK (1.49+/-0.13, range 1.26-1.78, confidence interval 1.45-1.53) and controls (1.55+/-0.17, range 1.16-1.98, confidence interval 1.47-1.51). No significant correlation between temporal contrast sensitivity and visual acuity could be found in patients after PK or in normals ( r<0.2, P=0.3). In patients after PK, temporal contrast sensitivity was statistically independent of keratometric astigmatism ( r=0.3, P=0.7), topographic astigmatism ( r=0.3, P=0.4), spherical equivalent ( r=0.07, P=0.7), central corneal thickness ( r=-0.06, P=0.7) and time since operation ( r=-0.07, P=0.6). CONCLUSIONS: Temporal contrast sensitivity using full-field flicker stimulation seems to be feasible in patients after PK and does not depend on topographic changes of the cornea. The results indicate that the full-field flicker test may be helpful as a supplementary means of detecting early glaucoma caused by ocular hypertension in patients after PK.