|Year : 2016 | Volume
| Issue : 1 | Page : 17-21
Primary angle-closure glaucoma: A retrospective interventional case series in South India
HH Suresh1, HR Samhitha1, H Kishore2, Krishna Prasad1, Sneha Solse1, P Divya1
1 Department of Ophthalmology, Minto Ophthalmic Hospital, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
2 Department of Ophthalmology and Adult Strabismus, Al Nahdha Hospital, Ministry of Health, Muscat, Oman
|Date of Web Publication||10-Feb-2016|
H R Samhitha
No. 67, Sukruti, Singapore Gardens, Greenfields 2, Gubbalala Gate, Kanakapura Main Road, Bengaluru - 560 062, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Purpose: To report the outcome of surgically managed primary angle-closure glaucoma (PACG) cases in 84 eyes at a tertiary eye hospital in South India.
Materials and Methods: Retrospective analysis of medical records of 84 eyes of 81 patients with PACG, who were surgically managed over 4 years at tertiary eye hospital in South India. Data were obtained from medical and surgical records of the patients identified from October 2010 to October 2014. The patients were operated by two surgeons in the Glaucoma Department of the institute.
Results: The patients' mean age at surgery was 56.21 years. Twenty-four eyes with a mean intraocular pressure (IOP) of 45.8 mmHg underwent trabeculectomy, and 60 eyes with a mean IOP of 29.9 mmHg underwent trabeculectomy with cataract extraction with or without intraocular lens implantation with good postoperative IOP control. A statistically significant greater reduction in IOP was noted in 14 patients who underwent augmentation with Mitomycin C (P = 0.0060, Student's t-test).
Conclusion: Knowing the risk factors, the diagnostic methods and treatment options for PAC disease is vital to every ophthalmologist as it is potentially treatable yet visually debilitating if untreated. Trabeculectomy or trabeculectomy with cataract extraction preferably with antifibrotics is an excellent treatment modality for PACG, which also effectively halts the disease progression.
Keywords: Glaucoma, mitomycin C, primary angle-closure, trabeculectomy
|How to cite this article:|
Suresh H H, Samhitha H R, Kishore H, Prasad K, Solse S, Divya P. Primary angle-closure glaucoma: A retrospective interventional case series in South India. Oman J Ophthalmol 2016;9:17-21
|How to cite this URL:|
Suresh H H, Samhitha H R, Kishore H, Prasad K, Solse S, Divya P. Primary angle-closure glaucoma: A retrospective interventional case series in South India. Oman J Ophthalmol [serial online] 2016 [cited 2021 May 16];9:17-21. Available from: https://www.ojoonline.org/text.asp?2016/9/1/17/176095
| Introduction|| |
Glaucoma is a potentially vision-threatening yet preventable and treatable disease affecting over 60 million people worldwide. It is the second leading cause of blindness according to the World Health Organization. It was described as early as thirteenth century as "migraine of eye" or "headache of pupil."  Blindness from glaucoma is 6 to 8 times more common in African-Americans than Caucasians.  However, a disproportionate part of glaucoma blindness occurring in Asians is due to primary angle-closure (PAC) disease.  PAC glaucoma (PACG) is equally prevalent in Indian population as is primary open-angle glaucoma (POAG).  Eighty-six percent of people with PACG are in Asia with approximately 48% in China, 23.9% in India, and 14.1% in South-East Asia.
The developing countries harbor most of PACG patients and 80% of them are unaware of their affliction. Visual impairment from PACG is also more severe compared to POAG.  According to a review by Day et al., accounting for age-related changes, PACG is expected to rise by 19% in the UK, 9% in Europe, and 18% in the USA within the next decade.  This is the magnitude of the problem that it requires systematic analysis of the risk factors, clinical recognition of disease per se, and treatment options available. Hence, the need for comprehensive epidemiological studies to highlight the severity of the disease in any given population thereby forming a basis to effectively manage the disease. We have done one such retrospective study in South Indian population.
The International Society of Geography and Epidemiology of Ophthalmology classified PAC disease into PAC suspect (PACS), closure (PAC) and glaucoma (PACG) based on intraocular pressure (IOP), gonioscopy findings, disc, and visual field examination. A knowledge of signs and symptoms of PAC disease is essential for identifying and treating the disease. A study of worldwide PACG showed that one-fifth of patients were asymptomatic at the time of detection.  Patients with a benign symptom of headache may turn out to have subacute angle-closure glaucoma on examination.  Clinical data of patients with angle-closure disease can be useful in understanding the disease manifestations and create a general awareness, which can lead to increased rates of detection and help in reducing morbidity due to PACG. The present study consists of demographic profile, symptoms, signs, and surgical details of PAC patients who were surgically treated at a tertiary care center in South India.
| Materials and Methods|| |
The present study is a retrospective analysis of medical records of patients diagnosed with angle-closure disease who were surgically managed at Regional Center of Ophthalmology over 2 years. The study was conducted in South Indian population including both urban and rural population.
Records of 366 patients who underwent trabeculectomy (with or without additional procedures) over last 2 years, January 2013-December 2014, were examined to identify the patients diagnosed with angle-closure disease. All patients with features of PAC disease who did not have adequate IOP control with neodymium-doped: Yttrium aluminum garnet laser peripheral iridotomy or who presented with significant glaucomatous optic disc or visual field changes requiring surgery were included for analysis. Demographic profile of each patient was noted. Clinical profile consisted of vision, anterior segment evaluation including Van Herick peripheral anterior chamber (AC) depth evaluation, intraocular lens (IOL) status, IOP by Goldmann applanation tonometer, gonioscopy by Zeiss 4 mirror, and slit lamp biomicroscopy with 78D or 90D lens to document disc changes. Patients underwent trabeculectomy alone, trabeculectomy with Mitomycin C (MMC), trabeculectomy with cataract surgery with IOL implantation or trabeculectomy with cataract surgery with IOL implantation with MMC. Postoperative vision and IOP were documented. Any postoperative complications were recorded.
Data were analyzed and tabulated. Statistical analysis was done by ANOVA and Student's t-test based on the specific data analyzed.
| Results|| |
The study consists of 84 eyes of 81 patients. Three patients (3.71%) which included two females and one male had bilateral eye surgery. Rest of the patients had a surgery in one eye. Left eye operated in 40 (49.38%) patients and right eye in 38 (46.91%) eyes.
Forty (49.4%) were female and 41 (50.6%) were male. 16 patients (20.9%) had comorbidities including 7 diabetic, 8 hypertensive, and 2 asthmatic patients. Mean age of patients was 56.21 years (standard deviation [SD] 11.97 years). The detailed age-wise distribution of all male and female patients is demonstrated in [Table 1].
Of 84 eyes, 4 eyes (4.8%) presented with an acute attack. Rest of the 80 eyes had chronic angle closure. 3 eyes were PACS, 1 had PAC. 76 eyes (90.5%) had PACG. In the PACG group, 2 (2.4%) patients had associated pseudoexfoliation and 2 (2.4%) had associated retinitis pigmentosa.
The preoperative visual acuity in the eye to be operated ranged from absent perception of light (PL negative) to 6/6 Snellen's vision. The distribution of the preoperative visual acuity among the patients is demonstrated in [Table 2]. Two patients of PL negative vision remained PL negative postoperatively. Of the 4 patients with PL vision, 2 patients improved to PL+, 1 patient to counting finger (CF), and 1 to Snellen's visual acuity. Two patients of 10 PL+ patients remained PL+ while 5 and 3 of them gained CF and Snellen's vision, respectively. In patients with hand movements (HMs) to CFs vision preoperatively, 9 patients experienced a postoperative drop in visual acuity by 0.25-0.5 m which improved to preoperative vision or more over 1-month follow-up, 6 patients remained stationary and 21 patients had improvement in visual acuity by at least 1 m CFs in 5 patients and rest 16 patients improving to Snellen's vision. Of the 32 patients with preoperative Snellen's vision, 11 patients' vision deteriorated to CFs or HMs whereas 21 patients retained Snellen's vision postoperatively. These 11 patients regained vision within 2 lines of the preoperative Snellen's vision. Of the total 81 patients, only 20 (24.7%) patients demonstrated a decreased visual acuity immediate postoperatively which could be attributed to the postoperative inflammation and/or corneal edema.
[Table 3] shows the preoperative intraocular pressure in our patients. All patients received preoperative oral and topical antiglaucoma medication, 18 patients achieved IOP <20 mm of Hg and 3 of them had an IOP <10 mm of Hg. Of these 18 patients, 14 patients had advanced glaucomatous disc changes and, hence, were considered for surgery in spite of good IOP control. 4 patients had frequent hospital visits with uncontrolled spikes of IOP in spite of topical and oral medication and laser peripheral iridotomy and, hence, were considered for surgery in spite of preoperative IOP <20 mm of Hg. All patients had good intraocular pressure control at the last follow-up visit postoperatively. Two patients had a postoperative spike in IOP controlled with ocular massage or medical therapy, not requiring re-surgery.
[Table 4] demonstrates the distribution of disc changes in our patients in the operated eye. 5 of the 7 patients with 0-0.5 cup-to-disc ratio (CDR) had glaucomatous changes in the contralateral eye. Of the 69 patients with >0.6 CDR, 54 patients had glaucomatous changes in the contralateral eye. 4 of the 8 patients in whom the operated eye fundus could not be visualized had glaucomatous changes in the contralateral eye. 64 (79%) of the 81 patients included in the study had evidence of glaucoma in contralateral eye.
All patients had a shallow peripheral AC (Von Herick's grade 2 or less). The central AC depth measured by A-mode ultrasonography had a mean of 2.71 mm (SD 0.56 mm). The lens thickness measured averaged 4.04 mm (SD 0.8 mm) by the A-mode ultrasonography. The mean axial length in our series was measured to be 22.53 mm (SD 0.58 mm).
The patients included in the study were subjected to either trabeculectomy or trabeculectomy combined with plain cataract extraction or cataract extraction (small incision cataract surgery or phacoemulsification) with IOL implantation with or without MMC augmentation. The number of patients undergoing these various procedures is demonstrated in [Table 5].
In patients who underwent trabeculectomy alone, mean pre- and post-operative IOP was recorded to be 38.76 mm of Hg (SD 15.43 mm of Hg) and 14.63 mm of Hg (SD 8.79 mm of Hg), respectively. Patients who underwent augmented trabeculectomy with MMC had a mean pre- and post-operative IOP of 29.5 mm of Hg (SD 15.15 mm of Hg) and 12 mm of Hg (SD 3.02 mm of Hg), respectively. The mean preoperative IOP in patients who underwent trabeculectomy with cataract extraction was 33.74 mm of Hg (SD 15.87 mm of Hg), which reduced to 18.89 mm of Hg (SD 9.28 mm of Hg) postoperatively. The mean IOP preoperatively was recorded to be 38.53 mm of Hg (SD 15.05 mm of Hg) and postoperatively as 14.4 mm of Hg (SD 8.93 mm of Hg) in patients who underwent augmented trabeculectomy with cataract extraction. [Table 6] shows the postoperative complications and the subsequent management of each.
| Discussion|| |
Our study consists of South Indian population with both urban and rural patients. A majority (95%) of our patients were asymptomatic at the time of admission with only 4 patients presenting with an acute attack of angle-closure glaucoma. Vijaya et al. had showed in their study that PACS is equally prevalent in both urban and rural population and both groups; a majority of the patients were asymptomatic.  PACG may not be detected until it causes significant visual loss due to progressive disc changes and retinal nerve fiber layer loss, hence significantly contributing to ocular morbidity in glaucoma.
PACG is found commonly in the sixth to seventh decades of life.  Mean age of presentation in our study was 56.21 years. Older studies have reported occurrence of PACG 2-3 times more commonly in females.  Our patients had an almost equal sex distribution (sex ratio - 1.025:1); however, in the patients belonging to the fifth and sixth decade, females were more than males (sex ratio 1:1.44).
Eighty (95.2%) of the eyes in our study had a chronic disease as opposed to 4 (4.8%) with acute. The majority of the global glaucoma burden is comprised of asymptomatic chronic PACG and POAG. Estimated 1 case of acute angle-closure glaucoma is found for every 3 chronic cases.  This is because most patients do not know that they have the disease. Even in patients with chronic angle-closure disease in our patients, PACS and PAC were only 4 (4.8%) and PACG comprised 76 (90.5%) patients demonstrating the burden of the disease. Optic disc changes are also worse in chronic cases compared to acute cases. 
George et al., Ho et al., Li and Cui, and Huang et al. demonstrated in various studies that eyes with angle-closure glaucoma and occludable angles had a significantly shorter axial length, shallower AC depth, and greater lens thickness compared to normal population. ,,, We recorded a mean central AC depth, lens thickness, and axial length of 2.71 mm (SD 0.56 mm), 4.04 mm (SD 0.8 mm), and 22.53 mm (SD 0.58 mm), respectively. George et al. recorded lens thickness, central AC depth, and axial length of 4.40 mm (SD 0.78 mm), 2.53 mm (SD 0.26 mm), and 22.07 mm (0.69 mm), respectively.
PL negative vision in 2 patients was corresponded to glaucomatous optic atrophy with uncontrolled IOP resulting in no change postoperatively in spite of IOP control. We noticed worsening of visual acuity in immediate postoperative period in 20 (24.7%) patients, which can be attributed to postoperative inflammation and corneal edema. These 20 patients regained vision within 1-month follow-up but not to preoperative levels, which can be attributed to the glaucomatous optic nerve damage. IOP control alone does not guarantee control of the disease as it is the most easily identifiable and modifiable risk factor for the disease. However, an improvement of visual acuity with a controlled IOP was noted in 61 (75.3%) patients, which is partly due to cataract removal in some patients. The majority of these patients did not have advanced glaucomatous damage. The progression of the disease can be halted by early intervention.  Screening for PACG in the general population becomes necessary for the early identification to save useful vision and prevent ocular morbidity.
All 84 eyes of our patients had good postoperative IOP control <20 mmHg. IOP reduction in PACG patients, especially chronic cases has known to be prevent progressive glaucomatous damage and halt progression of the disease process. 
The surgical method used has a bearing on the IOP control and effectiveness of the treatment for PACG. A meta-analysis by Deng et al. in 2011 has demonstrated that combined trabeculectomy with cataract surgery is better than trabeculectomy alone which in turn is better than a cataract surgery with IOL implantation for decreasing IOP. They did not, however, find a statistically significant difference in the three groups.  Our patients had a 64.6% reduction in IOP with trabeculectomy in 24 (28.6%) eyes and a 42% reduction with trabeculectomy combined with cataract surgery in 60 (71.4%) eyes. This difference in reduction of IOP with trabeculectomy alone or trabeculectomy with additional procedure was not found to be statistically significant (P = 0.118, Student's t-test). Brown et al. have demonstrated that the magnitude of IOP reduction correlates with the preoperative IOP for each case.  In our study, the preoperative IOP is higher (45.8 ± 17.6 mmHg) in the trabeculectomy alone group over the trabeculectomy with combine procedure group (29.9 ± 16 mmHg), both achieving 16-17 mmHg postoperative IOP. This preoperative IOP difference could be a compounding factor in comparing the effectiveness of the two groups. Further studies are required to determine the effectiveness of surgical intervention in correlation with the preoperative IOP.
Tsai et al. have demonstrated equal effectiveness of a combined trabeculectomy with cataract surgery and trabeculectomy alone, with the added advantage of fewer subsequent surgical interventions with combined procedure.  Other studies show that cataract surgery reduced IOP in patients with narrow angles, better IOP control by reducing the nocturnal fluctuations. , The long-term pressure reduction after cataract surgery is in the order of 2-4 mmHg.  Emanuel et al. showed that cataract extraction may be more effective in controlling the IOP than laser or incisional glaucoma procedures.  We suggest that trabeculectomy combined with cataract surgery is a better treatment option for patients presenting with PACG, especially in rural population as many of them are lost to follow-up. It has the added advantage of restoring the vision lost due to cataract which adds on to the ambulatory vision in patients with advanced glaucomatous disc changes. In addition, studies report a high likelihood for a subsequent cataract procedure following trabeculectomy to compromise a preexisting filter with bleb failure rate as high as 30-40%. , In fact, in patients of PACG without cataract, clear lens extraction with trabeculectomy may be considered.  Man et al. have also shown that cataract extraction resulted in a significant reduction in synechial angle closure and an increased AC angle width and depth in PACG eyes without cataract. 
In our patients, 14 eyes that had surgical procedure augmented with use of MMC had a statistically significant greater IOP reduction over those without use of MMC (P = 0.006, Student's t-test). This is in accordance with other studies.  Choice of using MMC is individualized for each case based on the specific contraindications.
Fourteen eyes of 14 patients in our study developed postoperative complications, 6 of whom underwent trabeculectomy alone and 8 patients underwent triple procedure. Incidentally, none of the patients were treated with MMC. Of the complications, hypotony and over-filteration were the most common (6 eyes, 7% of total) which is in concordance with other studies. 
| Conclusion|| |
Blindness ranks third as a major fear for people as per numerous surveys, of which glaucoma is the major contributor. Of the 60 million with glaucoma in the world, more than 1/3 rd have PACG with 25% of these being blind (more than twice the blind due to POAG). People with lower levels of education have a higher risk of incident PACG, independent of age, sex, IOP, and axial length. Estimated 10 million visits to physicians every year and $ 1.5 billion are lost annually due to glaucoma. PACG is an important health burdens but because of the absence of a good screening test and the opportunity costs involved, population-based screening will probably be unfeasible in developing countries. However, training ophthalmologist and paraophthalmic staff to identify PACG are of utmost importance for early diagnosis and management. The use of new imaging methods such as anterior segment optical coherence tomography to assess the presence or risk of angle closure is gaining popularity and may offer a more rapid method of identifying people who are at risk of sight loss from angle-closure glaucoma. Knowing the risk factors, the diagnostic methods and treatment options for PACG, is vital to every ophthalmologist as it is potentially treatable yet visually debilitating if untreated.
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Conflicts of interest
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]