Oman Journal of Ophthalmology

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 10  |  Issue : 3  |  Page : 150--154

The role of trabeculectomy in enhancing glaucoma patient's quality of life


Ibrahim H Binibrahim1, Anders K Bergström2,  
1 Department of Ophthalmology, Jeddah Eye Hospital, Jeddah, Saudi Arabia
2 Department of Ophthalmology, Sahlgrenska University Hospital, Mölndal, Gothenburg, Sweden

Correspondence Address:
Ibrahim H Binibrahim
Jeddah Eye Hospital, Jeddah
Saudi Arabia

Abstract

PURPOSE: Is to control intraocular pressure (IOP) (up to 21 mmHg), to decrease medical treatment after trabeculectomy and to slow down or stop progression and deterioration in visual fields in glaucoma patients. METHODS: A retrospective study. The charts of all trabeculectomies done in the Department of Ophthalmology at the Skåne University Hospital, Sweden during 2010 were retrospectively evaluated. The study was performed during fall 2012, so the longest follow-up is almost 2 years. RESULTS: In total, 38 patients (21 males and 17 females) underwent trabeculectomy. The IOP was measured in both visits (pre- and post-operative); with a difference of −15.49 mmHg (−50.09%) respectively, showing a very highly statistical significance (P < 0.001). The amount of antiglaucoma drops was measured before and after the trabeculectomy, of average 3.5 drops and 1.2 drops, respectively. Showing a −2.30 difference (−66.41%), illustrating a very highly statistical significant value (P < 0.001). From 36 patients, 17 patients (45%) took Diamox before trabeculectomy, whereas 19 patients (50%) did not. After the trabeculectomy, only 1 patient (3%) took Diamox and 35 patients (92%) stopped taking Diamox, showing a very highly significant statistical value (P < 0.001). The visual field was measured for 13 patients showing a difference of −13.22 (−21.86%) before and after the trabeculectomy. CONCLUSION: Trabeculectomy showed very high statistical significant results regarding IOP reduction and decrease in the amount of topical and systemic antiglaucoma medications.



How to cite this article:
Binibrahim IH, Bergström AK. The role of trabeculectomy in enhancing glaucoma patient's quality of life.Oman J Ophthalmol 2017;10:150-154


How to cite this URL:
Binibrahim IH, Bergström AK. The role of trabeculectomy in enhancing glaucoma patient's quality of life. Oman J Ophthalmol [serial online] 2017 [cited 2019 Sep 15 ];10:150-154
Available from: http://www.ojoonline.org/text.asp?2017/10/3/150/216011


Full Text

 Introduction



Glaucoma is a silent disease defined as “optic neuropathy;” it is characterized by the loss of peripheral vision and cupping of the optic nerve head. In the majority of cases, the intraocular pressure (IOP) is elevated and is a factor for the damage of the optic. This optic nerve damage may take the form of changes in the appearance of the optic disc or the nerve fiber layer or the presence of abnormality in visual fields. Several factors have been implicated as risk factors in the development of glaucomatous optic nerve damage such as elevated IOP, myopia, and changes in the appearance of the optic nerve, family history of glaucoma, age, black race, diabetes mellitus, and cardiovascular diseases. The majority of cases are discovered accidentally during regular check-ups. If early detected, the majority of cases can be successfully treated with laser treatment, surgery, or even medications. Glaucoma is a leading cause of visual impairment and blindness in the United States and worldwide.[1],[2],[3],[4],[5],[6]

So far known treatment is to lower the pressure, which has to be done before the optic nerve is damaged; since damaged nerve tissue cannot be restored. Standard pressure lowering treatment is eye drops and/or laser treatment. If not sufficient, surgery becomes an option.[7],[8]

The most frequently used intraocular surgery for glaucoma is trabeculectomy, which involves the creation of a partial-thickness scleral flap over a sclerectomy into the anterior chamber,[9] where an extra canal is created between the anterior chamber and the subconjunctival space.[8]

Traditionally, maximum tolerated medical therapy has been used before laser trabeculoplasty (LTP) or conventional surgery. Trabeculectomy lowers IOP by the creation of a new channel (guarded fistula) for aqueous outflow between the anterior chamber and subtenon space. If performed early, this filtering surgery gives excellent IOP control with minimal complications.[10]

Previous studies showed that in most of the cases visual acuity is maintained and IOP is controlled in the short-term period of 1 year through trabeculectomy. Therefore, conventional trabeculectomy can be effective in controlling IOP in glaucoma patients.[11]

The problem with the trabeculectomy and all other types of pressure lowering surgery is the excessive wound healing, which leads often to an increased postoperative pressure after some time. To investigate the pressure lowering effect of trabeculectomies this study was done at the Department of Ophthalmology at Skåne University Hospital in Sweden.

The objective of this study was to control IOP (up to 21 mmHg),[12],[13] to decrease medical treatment regarding number of drops after trabeculectomy and to slow down or stop progression and deterioration of the visual field.

 Materials and Methods



The charts of all trabeculectomies done in the Department of Ophthalmology at the Skåne University Hospital-Sweden in two clinics Lund and Malmö for about 2 years duration during 2010 were retrospectively evaluated. The age, gender, and diagnosis of patients were noted, history of any previous ocular surgery or laser treatment, as well as the last preoperative IOP measurement and the number of drops and/or Diamox administered at that time. If the visual field was done within 3 months before surgery, the visual field index (VFI) and the mean deviation (MD) were also noted. The same data were also collected from the last follow-up visit, either in the department or at another department in case the patient originally was referred from elsewhere. It was a retrospective study using charts; we have not registered the study or obtained permission from the ethics committee. The technique used was a slightly modified Moorefield Safe Surgery System. The type of surgery was also noted, and if Mitomycin C had been used or not, as well as if needling with or without 5-fluorouracil was done once or several times postoperatively. The study was performed during fall 2012, so the longest follow-up was almost 2 years.

Patient demography

At the initiation of the study, 64 patients were enrolled; 15 were followed up with other doctors, 9 did not complete their 3 months follow-up, one was not subject to a visual field examination, and 1 passed away. Twenty-six patients were excluded and 38 patients completed the study, as per protocol.

Twenty-one patients were diagnosed with primary open angle glaucoma, 11 had pseudo-exfoliative glaucoma, one had narrow-angle glaucoma, two had inflammatory glaucoma, one had secondary glaucoma, and two had unspecified glaucoma.

In this study, 38 patients (21 males and 17 females) underwent trabeculectomy. Patients' age ranged from 16 to 90 years old, with a mean 67.7 ± 16.6 years. The disease diagnosis code and distribution are shown in [Table 1].{Table 1}

 Results



The operation was done on 18 (47%) right eyes and 20 (53%) left eye. The data collected showed that 45% of patients (17 patients) had an operation before trabeculectomy; 39% of them had cataract extraction, 13% trabeculectomy, 5% nonpenetrating trabeculectomy, and 3% needling. There were 20 patients (53%) whom underwent trabeculoplasty; 50% underwent LTP and 8% selective laser trabeculoplasty. Postoperatively, no severe hypotony was noted.

There were numerous aspects that were measured before and after the trabeculectomy; IOP, IOP range, amount of eye drops, Diamox tablets intake, the MD and VFI.

The IOP was measured in both of the pre- and post-operative visits and the mean preoperative IOP was 30.9 mmHg (ranging from 15 to 70 mmHg), whereas postoperatively it decreased to 15.4 mmHg (ranging from 8 to 30 mmHg). This shows a difference of −15.49 mmHg (−50.09%) between the two visits, showing a very highly statistically significant difference (P < 0.001), as in [Table 2]. The IOP was divided into two groups; IOP ≤21 mmHg and IOP >21 mmHg. Thirty-three patients (89%) out of 37 patients had IOP >21 mmHg preoperative, which dropped to only 4 patients (11%) postoperative. These results convey a very high statistically significant difference (P < 0.001), as demonstrated in [Figure 1].{Table 2}{Figure 1}

In this study, the amount of antiglaucoma drops were measured before and after the trabeculectomy. Before the trabeculectomy 3.5 drops in average were applied, whereas after the trabeculectomy 1.2 drops were applied; showing a −2.30 difference (66.41% drop), illustrating a very highly statistical significant value (P < 0.001).

As previously mentioned, before the trabeculectomy 17 patients (45%) took Diamox and 19 patients (50%) did not. However, after the trabeculectomy, only 1 patient (3%) took Diamox out of 36 patients with a very highly statistical significant value (P < 0.001),

As shown in [Table 3], the MD for the visual field was calculated for 12 patients; the mean was 15.5 before trabeculectomy and became 24.7 after the trabeculectomy, showing 58.73% change (P > 0.05).{Table 3}

The VFI was measured for 13 patients before and after the trabeculectomy; before the trabeculectomy, the average was 60.5, while after the trabeculectomy, it decreased to 47.2 on average, showing a difference of − 13.22 (21.86% drop). P = 0.187, illustrating a nonsignificant statistical result [Table 3].

Only 30 patients (79%) used mitomycin C from the 38 patients. However, 5 patients out of them (15%) needed postoperative needling. Moreover, from the 37 patients, only 12 patients (32%) had 5-fluorouracil. The number of postoperative years follow-up was in average 1.7 years for 37 patients, with the minimum of 0.7 years and a maximum of 2.3 years.

No complication was reported during the follow-up period.

 Discussion



Glaucoma is the primary cause of irreversible blinding; it affects about 65 million worldwide.[14] Recent studies now emphasize a new concept for glaucoma; it is now considered optic neuropathy, where IOP is a main factor, however, it is one of the factors.[15],[16] Sometimes, IOP is not even mentioned now in new glaucoma definitions.[3],[17] The aim of glaucoma treatment is to preserve the visual field. This is usually done by achieving a target IOP and maintaining it. Since not only high IOP is a factor, but also the fluctuation of the IOP. Hence, the target pressure has to be checked to know IOP fluctuations, visual field progression or optic nerve changes exist.[18]

Trabeculectomy is the most common surgical procedure for the treatment of glaucoma since Cairns in 1968. The procedure is to remove a part of the trabecular meshwork, and a scleral flap is used to cover the sclerostomy, so between the anterior chamber and the subconjunctival space, a fistula is created.[8] Episcleral fibroproliferation which blocks the outlet of aqueous humor is the most common cause for failure of trabeculectomy. Fluorouracil and mitomycin are anti-cancer agents, used for single applications intraoperatively on a cellulose sponge for a few minutes or with postoperative subconjunctival injection to decrease the proliferative response. These agents have transformed surgery, particularly in patients with a high possibility of failure due to scarring.[19],[20],[21]

Ocular Hypertension Treatment Study showed conclusive evidence that in ocular hypertensive patients there is a decline in glaucoma damage as IOP is reduced. Glaucoma damage incidence after 60 months follow-up showed significant differences between treated and untreated patients, 4.4% and 9.5%, respectively.[22]

Moreover, AGIS (Advanced Glaucoma Intervention Study) illustrated that reduced progression of visual field defect is associated with low postintervention IOP. Moreover, the link became stronger as follow-up lengthened.[23] According to the Glaucoma Laser Trial, the results showed that after 7 years follow-up, IOP was reduced by 1.2 mmHg and visual field was improved by 0.6 dB in eyes treated with LTP.[24]

These prior studies back up our study findings. Our study showed very highly statistically significant results regarding IOP reduction, which has decreased by-50.9% after trabeculectomy and IOP ≤21 mmHg, has significantly increased from 11% of the patients to 89%. Therefore, the significant decrease in IOP conveys how surgery has affected the progression of glaucoma in the patients. Moreover, the amount of drops and oral antiglaucoma medication has also decreased, illustrating that the patients' quality of life has also improved.

Trabeculectomy is the procedure to preserve constant IOP reduction, and enhance the patient's quality of life.[25] In Europe, surgery is performed early in the course of treatment, without extensive use of medication.[26] A prospective, long-term multicenter study conducted in Scotland showed better IOP control results with early trabeculectomy when compared with conventional medical therapy.[27] Moreover, previous studies from the UK reported that surgery was superior to medical or laser therapy in reducing IOP and preserving vision.[10],[28]

 Conclusion



Our study shows that trabeculectomy has very high statistically significant results toward IOP reduction, decrease in amount of antiglaucoma drops and Diamox tablets.

Recommendations

Increase the level of awareness of glaucoma and its management for the public since it is a silent disease. Further prospective studies with a longer follow-up period are recommended to investigate the effect of trabeculectomy on the patients' IOP, postoperative complications and its effect on the patient's quality of life.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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