John F Salmon

Long term effect on intraocular pressure of phacotrabeculectomy compared to trabeculectomy

Aim: To compare the long term mean intraocular pressure (IOP) reduction after non-augmented single site phacotrabeculectomy with that after trabeculectomy and to determine the relation between preoperative IOP and IOP reduction. Methods: A group of 44 consecutive patients with chronic open angle glaucoma who underwent phacotrabeculectomy were matched to a trabeculectomy control group and the results of surgery were compared. Linear regression analysis of preoperative IOP and IOP reduction was undertaken. Results: The mean IOP reduction was significantly less in the phacotrabeculectomy group (6.7 (SD 2.1) mm Hg) than in the trabeculectomy group (11.0 (1.4) mm Hg) (p=0.0017). There was a significant difference in surgical success between the groups. The preoperative IOP was significantly related to the postoperative reduction in IOP in both groups (p<0.001). Conclusions: In elderly white patients with chronic open angle glaucoma, phacotrabeculectomy is not as effective as trabeculectomy in reducing IOP. In both procedures the magnitude of IOP reduction is proportional to the preoperative IOP.

Combined surgery in the treatment of patients with cataract and primary open-angle glaucoma

&NA; The literature on combined surgery in the treatment of patients with cataract and primary open‐angle glaucoma was comprehensively studied, and all aspects and variations of the combined procedure were assessed. Phacoemulsification has improved the success rate and reduced the complication rate previously associated with extracapsular cataract extraction combined with trabeculectomy. A mean reduction in intraocular pressure (IOP) of 5 to 8 mm Hg can be achieved. One‐ and 2‐site techniques appear to be similarly effective. Phacotrabeculectomy augmented with mitomycin‐C achieves a lower IOP than phacotrabeculectomy alone but has a higher complication rate. The use of 5‐fluorouracil is not as effective as mitomycin‐C and has a variable influence on the results. The development of new techniques that combine nonpenetrating glaucoma surgery with phacoemulsification offers interesting surgical alternatives, but no long‐term results have been reported.

Long term results and complications of trabeculectomy augmented with low dose mitomycin C in patients at risk for filtration failure

AIM To determine the results and complications up to 5 years after trabeculectomy with 0.02% mitomycin C (MMC) in glaucoma patients at risk for failure of filtration surgery. METHODS A consecutive series of 21 eyes from 20 patients who underwent trabeculectomy with MMC 0.02%, with an exposure time of 2 minutes, was retrospectively analysed and the results were compared with previously published data. RESULTS The mean preoperative intraocular pressure (IOP) was 28 mm Hg on an average of 2.8 glaucoma medications, and the mean postoperative IOP after 3 years was 14 mm Hg on an average of 0.4 medications. Three years after trabeculectomy, 17 of 21 (80.9%) eyes had an IOP of less than 21 mm Hg without medical treatment. Using Kaplan-Meier life table analysis the 5 year probability of an IOP less than 21 mm Hg without medication was 67% and with medication was 90%. Two patients required further glaucoma surgery during the first postoperative year, and another developed hypotonous maculopathy which was reversed after bleb revision. Seven patients developed visually significant cataract as a late consequence of the surgery. There were no bleb related infections. CONCLUSION In the long term MMC 0.02% used for 2 minutes intraoperatively is an effective adjunctive treatment in glaucoma patients at risk for bleb failure and in this dose is associated with few complications.

Phacoemulsification with intraocular lens implantation after trabeculectomy.

PurposeTo determine the effect of phacoemulsification with intraocular lens (IOL) implantation, using a superior clear-corneal incision, on the long-term intraocular pressure (IOP) control in patients who have undergone previous trabeculectomy. MethodsTwenty-eight consecutive patients who underwent phacoemulsification with IOL implantation (phaco group) at least 3 months after trabeculectomy were identified and matched to 28 patients who underwent trabeculectomy only (trabeculectomy-only group) with respect to age, gender, IOP, and duration of follow-up. The mean IOP was compared 1 and 2 years after phacoemulsification, and the surgical success rate in each group was determined by Kaplan-Meier survival analysis. ResultsThe mean IOP 1 year after cataract surgery was significantly higher (P = 0.025) in the phaco group (15.6 ± 3.5 mm Hg) than in the trabeculectomy-only group (13.4 ± 2.5 mm Hg), but at 2 years the difference was not statistically significant (15.3 ± 3.1 mm Hg in the phaco group compared with 14.3 ± 3.2 mm Hg in the trabeculectomy-only group;P = 0.35). Two years after surgery, 5 of 28 patients in the phaco group and 1 of 28 patients in the trabeculectomy-only group had commenced or were using additional topical medication (P = 0.089). If the introduction of glaucoma medication was considered a “failure,” then the IOP control was significantly better in the trabeculectomy-only group using two different criteria for surgical failure. ConclusionAlthough phacoemulsification and IOL implantation through a superior clear-corneal incision have little effect on mean IOP in a group of patients who have undergone previous trabeculectomy, this procedure may jeopardize the long-term IOP control in individual patients.

Normal tension glaucoma is not associated with the common apolipoprotein E gene polymorphisms

Background/aims: In normal tension glaucoma (NTG) factors other than raised intraocular pressure have a role in the pathogenesis of the optic neuropathy. Because particular apolipoprotein E (ApoE) gene polymorphisms have been associated with cell death and survival in neurological degenerative diseases, the purpose of this study was to determine the ApoE allele frequencies in patients with normal tension glaucoma. Methods: The apolipoprotein E genotype of 155 patients with normal tension glaucoma was compared to that of 349 non-affected, control subjects from the same geographical area. A similar comparison was made between 53 patients with normal tension glaucoma who demonstrated progressive visual field loss, and control subjects. The frequencies of genotypes was compared with the χ2 test and Mantel-Haenszel coefficent. Results: There was no significant difference in the frequency of ApoE alleles or genotypes in the normal tension glaucoma population compared to the control group. The ApoE alleles and genotypes in NTG patients with progressive disease were not different from the control group. Conclusion: ApoE gene polymorphisms are not linked to normal tension glaucoma, suggesting that this gene does not have a role in the pathogenesis of optic neuropathy in this disease.

Long-term effect of cataract surgery on intraocular pressure after trabeculectomy: extracapsular extraction versus phacoemulsification.

Purpose: To compare the effect of phacoemulsification with intraocular lens (IOL) implantation on long‐term intraocular pressure (IOP) control in glaucoma patients who had previous trabeculectomy with the effect on IOP control in similar patients after extracapsular cataract extraction (ECCE) with IOL implantation Setting: Oxford Eye Hospital, Oxford, England. Methods: Twenty‐eight consecutive patients who had phacoemulsification with IOL implantation (phaco group) at least 3 months after trabeculectomy were identified from hospital records, and 28 patients who had ECCE with IOL implantation (ECCE group) were matched retrospectively to the phaco group with respect to age, sex, diagnosis, and IOP. In both groups, the IOP before cataract extraction was compared with the IOP at intervals up to 2 years after cataract extraction. A Kaplan‐Meier survival analysis was performed. Results: The mean IOP in the phaco group did not differ significantly from the mean IOP before cataract extraction at any interval. Twelve months after cataract extraction, the mean IOP in the ECCE group was significantly higher than preoperatively (P = .01); however, the mean IOP did not differ between groups over time (P = .704). There was significantly better long‐term IOP control in the phaco group as determined by Kaplan‐Meier survival analysis and the log‐rank test (P = .038). Conclusion: After trabeculectomy, phacoemulsification provided better long‐term IOP control than ECCE; however, the mean IOP was not significantly lower.

Trends in rates of primary angle closure glaucoma and cataract surgery in England from 1968 to 2004.

AimEyes that are predisposed to primary angle closure usually have a shallow anterior chamber secondary to a relatively forward position of the lens and progressive lens thickening with ageing. The aim of this study was to examine trends over time in rates of primary angle closure glaucoma (PACG) in England, and to compare these rates with rates of cataract surgery. MethodsHospital episode statistics and the hospital inpatient inquiry were analyzed for PACG as the main diagnosis between the years 1968 and 2004, and for cataract surgery over the same period. Age-specific and sex-specific rates of PACG and cataract surgery were calculated over 3 representative time periods. ResultsAnnual rates of patients with PACG did not change significantly from the late 1960s to the mid-1980s and then increased until the early 1990s before reaching a plateau; from 1999 to 2004, rates of patients with PACG declined significantly. From the 1980s to 2004, annual rates of patients undergoing cataract surgery increased significantly and substantially. In the recent period of decline in PACG, the decline was greatest in older age groups, whereas rates of cataract surgery increased significantly in all age groups for both men and women throughout the whole time period. ConclusionsRates of patients with PACG have started to decline in recent years, after a long period of increases in rates of patients undergoing cataract surgery. Although other explanations are possible, this lends support to the hypothesis that cataract surgery may reduce the likelihood of acute angle closure.

Trends in rates of trabeculectomy in England

AimsRates of glaucoma surgery have declined in North America and continental Europe in recent years. The aim of this study was to examine trends over time and regional variation in rates of trabeculectomy in England.MethodsThe hospital in-patient enquiry (HIPE), hospital episode statistics (HES), and the Oxford record linkage study (ORLS) were analysed for annual trabeculectomy admissions between 1976 and 2004.ResultsAnnual rates of admission for trabeculectomy rose 10-fold from 1976 to 1995: from 3.7 (95% confidence intervals 3.5–3.9) admissions per 100 000 population in 1976 to a peak of 38.7 (38.1–39.3) in 1995. Admission rates then declined sharply and have begun to reach a plateau at around 10.6 (10.3–10.9) in 2004. The highest surgical rates during the period 1997–2004 were found in the 80- to 84-year-old age group. Geographical analysis showed wide variation across local authority areas in annual rates of trabeculectomy, from 4 (2.3–5.2) to 33 (29.0–36.5) people per 100 000 population in 1998–2004. The rate of surgery by local authority showed little or no association with the level of social deprivation in each area.ConclusionsThe rate of patients undergoing trabeculectomy increased substantially over 20 years. This was followed by a profound reduction in rates of trabeculectomy from 1995, which coincides with the introduction of new topical medications to reduce intraocular pressure. Wide regional variation in rates of trabulectomy was found, but there was no evidence of reduced access to glaucoma surgery in deprived areas.

There is a trend for the diagnosis of glaucoma to be made at an earlier stage in 2010 compared to 2008 in Oxford, United Kingdom

New guidelines on glaucoma diagnosis and management were published by the National Institute of Clinical Excellence (NICE) in 2009. The aim of this study was to determine whether these guidelines on glaucoma referral have changed the numbers of patients diagnosed with glaucoma in Oxford and whether the severity of disease at presentation has altered between 2008 and 2010.

An analysis of patients discharged from a hospital‐based glaucoma case‐finding clinic over a 3‐year period

Purpose:  To analyse the false positive referrals by community optometrists to a glaucoma case‐finding clinic over a 3‐year period.