Steroid-induced glaucoma: an avoidable cause of irreversible blindness.

A man in his 70s on regular follow-up with an ophthalmologist for 10 years presented with blurry vision in his right eye for 4 days. He was diagnosed with elevated intraocular pressure (IOP) bilaterally 18 months earlier and treated with antiglaucoma eye-drops. On direct questioning, he admitted to using fixed combination tobramycin 0.3%/dexamethasone 0.1% eye-drops frequently to relieve ocular redness and discomfort in both eyes for 3.5 years without his ophthalmologist's knowledge. Examination disclosed markedly elevated IOP, advanced optic disc cupping and tunnel vision due to steroid-induced glaucoma bilaterally. After cessation of the eye-drops and 2 weeks of antiglaucoma therapy, his IOP returned to normal and his visual field remained stable for 4 years.Our case highlights the danger of habitual self-treatment of prescription medications containing corticosteroids and the importance of taking a detailed medication history in the diagnosis and management of steroid-induced glaucoma.

Fructus lycii: A Natural Dietary Supplement for Amelioration of Retinal Diseases.

Fructus lycii (F. lycii) is an exotic "berry-type" fruit of the plant Lycium barbarum that is characterized by a complex mixture of bioactive compounds distinguished by their high antioxidant potential. F. lycii is used in traditional Chinese home cooking and in the Chinese Pharmacopeia as an aid to vision and longevity as well as a remedy for diabetes to balance "yin" and "yang" in the body for about two centuries. Although a myriad of bioactive compounds have been isolated from F. lycii, polysaccharides, carotenoids, flavonoids, and phenolics represent the key functional components of F. lycii. F. lycii has been shown to exhibit a wide range of biological activities in experimental settings including antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects. Despite its medicinal role dating back to the eighteenth century in the Far East and robust evidence of beneficial effects on ocular health and retinal diseases originating mainly from studies in animal models, the role of F. lycii in the clinical management of retinal diseases is yet to be established. This article comprehensively reviews the literature germane to F. lycii and retinal diseases with particular emphasis on age-related macular degeneration, diabetic retinopathy, and retinitis pigmentosa, which are commonly seen in clinical practice.

Putative protective role of lutein and zeaxanthin in diabetic retinopathy.

Diabetic retinopathy (DR) is one of the most important microvascular complications of diabetes and remains the leading cause of blindness in the working-age individuals. The exact aetiopathogenesis of DR remains elusive despite major advances in basic science and clinical research. Oxidative damage as one of the underlying causes for DR is increasingly being recognised. In humans, three hydroxycarotenoids, lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ), accumulate at the central retina (to the exclusion of all other dietary carotenoids), where they are collectively known as macular pigment. These hydroxycarotenoids by nature of their biochemical structure and function help neutralise reactive oxygen species, and thereby, prevent oxidative damage to the retina (biological antioxidants). Apart from their key antioxidant function, evidence is emerging that these carotenoids may also exhibit neuroprotective and anti-inflammatory function in the retina. Since the preliminary identification of hydroxycarotenoid in the human macula by Wald in the 1940s, there has been astounding progress in our knowledge of the role of these carotenoids in promoting ocular health. While the Age-Related Eye Disease Study 2 has established a clinical benefit for L and Z supplements in patients with age-related macular degeneration, the role of these carotenoids in other retinal diseases potentially linked to oxidative damage remains unclear. In this article, we comprehensively review the literature germane to the putative protective role of two hydroxycarotenoids, L and Z, in the pathogenesis of DR.

Perioperative glycaemic control in diabetic patients undergoing cataract surgery under local anaesthesia: a survey of practices of Singapore ophthalmologists and anaesthesiologists.

INTRODUCTION: Perioperative glycaemic control is an important aspect of clinical management in diabetic patients undergoing cataract surgery under local anaesthesia. While poor long-term glycaemic control has significant implications for surgery, perioperative hypoglycaemia or hyperglycaemia may also compromise patient safety and surgical outcomes. We aimed to survey ophthalmologists and anaesthesiologists on their approach and to identify the prevalent practice patterns in Singapore. METHODS: This was a cross-sectional questionnaire-based survey conducted in four public hospitals in Singapore with established ophthalmology and anaesthesia units. Respondents were approached individually, and the self-administered questionnaires comprised questions related to practice patterns, clinical scenarios and awareness of pre-existing guidelines. RESULTS: A total of 129 doctors responded to the questionnaire survey. 76 (58.9%) were from ophthalmology departments and 53 (41.1%) were from anaesthesia departments. The majority chose to withhold oral hypoglycaemic agents (82.9%) and/or insulin (69.8%), and keep the patient fasted preoperatively. A blood glucose level ≥ 17 mmol/L prompted 86.0%-93.8% of respondents to adopt a treat-and-defer strategy, while a level ≥ 23 mmol/L prompted 86.0%-96.9% of respondents to cancel the cataract surgery. The respondents were consistently more concerned about perioperative hyperglycaemia (n = 99, 76.7%) than intraoperative hypoglycaemia (n = 83, 64.3%). CONCLUSION: The current study presented the prevalent practice patterns of ophthalmologists and anaesthesiologists in the perioperative management of diabetic patients undergoing cataract surgery in four public hospitals in Singapore. Further research in this field is required, and may be useful for the future formulation of formal guidelines and protocols.

Effect of preoperative counseling on fear from visual sensations during phacoemulsification under topical anesthesia.

PURPOSE: To determine whether preoperative counseling on possible intraoperative visual perceptions during cataract surgery helps reduce the patients' fear during surgery. SETTING: Aravind Eye Hospital, Madurai, India. DESIGN: Randomized masked clinical trial. METHODS: Patients having phacoemulsification under topical anesthesia were randomized to receive additional preoperative counseling or no additional preoperative counseling on potential intraoperative visual perceptions. After surgery, all patients were interviewed about their intraoperative experiences. RESULTS: Of 851 patients, 558 (65.6%) received additional preoperative counseling and 293 (34.4%) received no additional counseling. A lower proportion of patients in the counseled group were frightened than in the group not counseled for visual sensation (4.5% versus 10.6%, P<.001). Analyzed separately by specific visual sensations, similar results were found for light perception (7/558 [1.3%] versus 13/293 [4.4%], P=.007), colors (P=.001), and movement (P=.020). The mean fear score was significantly lower in the counseled group than in the not-counseled group for light perception (0.03 versus 0.12, P=.002), colors (P=.001), movement (P=.005), and flashes (P=.035). Preoperative counseling was a significant factor affecting fear after accounting for age, sex, operated eye, and duration of surgery (multivariate odds ratio, 4.3; 95% confidence interval, 1.6-11.6; P=.003). CONCLUSION: Preoperative counseling on possible visual sensations during cataract surgery under topical anesthesia significantly reduced the mean fear score and the proportion of patients reporting being frightened.

Analgesic effect of supplemental intracameral lidocaine during phacoemulsification under topical anaesthesia: a randomised controlled trial.

AIMS: To determine the analgesic effect of supplemental intracameral lidocaine 1% during phacoemulsification under topical anaesthesia, and to assess the risk factors associated with pain. METHODS: In a double-masked, randomised, clinical trial, 506 patients undergoing phacoemulsification under topical anaesthesia were randomised to receive a supplemental intracameral injection of either 0.5 cc of 1% lidocaine (277 patients, 54.7%) or balanced salt solution (BSS) (229 patients, 45.3%). Patients were interviewed by a trained interviewer using a standardised questionnaire. The main outcome measure was intraoperative pain, scored on a visual analogue scale of 0-10. Logistic regression was performed to assess ORs. RESULTS: 125 of 277 patients (45.1%) experienced pain in the lidocaine group, compared with 123 of 229 patients (53.7%) in the BSS group. The proportion of patients who experienced pain was significantly lower in the intracameral lidocaine group compared with the BSS group (multivariate OR 0.68, 95% CI 0.47 to 0.97; p=0.034). The median pain score (range) was 0.0 for intracameral lidocaine group compared with 1.0 for BSS group (p=0.039). Pain was more common in females (54.3% vs 43.6%; OR 1.56), non-Chinese (62.3% vs 46.9%; OR 2.13) and those who had previous cataract surgery to the fellow eye (55.3% vs 44.7%; OR 1.61). CONCLUSION: The use of 0.5 cc of 1% intracameral lidocaine during phacoemulsification under topical anaesthesia significantly reduces pain experienced by patients. Risk factors for pain include females, non-Chinese and previous cataract surgery.

Visual experience during phacoemulsification-trabeculectomy under peribulbar anesthesia.

BACKGROUND AND OBJECTIVE: To investigate the subjective visual experience of patients with concurrent cataract and glaucoma during phacoemulsification-trabeculectomy under peribulbar anesthesia. PATIENTS AND METHODS: Consecutive patients with concurrent cataract and glaucoma who underwent phacoemulsification-trabeculectomy under peribulbar anesthesia for the first time were interviewed using a standardized questionnaire between 30 minutes and 4 hours after the surgery. They were asked about their intraoperative visual experiences and their reaction to their visual experience. There was no preoperative discussion with the patients on possible intraoperative visual sensations that they might experience. No preoperative or intraoperative sedation was used. RESULTS: Sixty patients with a mean age of 64.8 years (range: 41 to 86 years) were included in the study. Light perception was reported by 73.3% of patients and no light perception by 26.7% throughout the operation. Some patients reported they could also see movements (65%), flashes (53.3%), one or more colors (48.3%), a change in light brightness (38.3%), instruments (8.3%), and/or the surgeon/medical staff (1.7%). Of the 29 patients (48.3%) who saw one or more colors, 18 patients saw yellow, 12 blue, 4 green, 2 orange, and 1 red. One patient (1.7%) found the visual experience frightening and the rest (98.3%) found theirs pleasant. CONCLUSION: The majority of patients with concurrent cataract and glaucoma undergoing phacoemulsification-trabeculectomy using peribulbar anesthesia experience a variety of visual sensations, although only a minority was frightened by the visual experience.

National survey of ophthalmologists in Singapore for the assessment and management of asymptomatic angle closure.

PURPOSE: Approximately 10% of Chinese people older than 50 years in Singapore have asymptomatic narrow angles [also termed primary angle closure suspects (PACS)]. The aim of this study was to determine the attitudes and practices of ophthalmologists in Singapore regarding the management of these patients. METHODS: A nation wide questionnaire-based survey was conducted on all registered, practicing ophthalmologists in Singapore by electronic mail and post. An ophthalmologist was defined as a doctor who had completed at least 3 years of specialist training in ophthalmology and had passed the Master's Degree in Ophthalmology or equivalent examinations. The survey asked the ophthalmologists about the methods and criteria used for the diagnosis of angle closure. It also inquired about the management of PACS and opinions on the effectiveness of prophylactic laser peripheral iridotomy (LPI) in preventing both acute and chronic angle closure. RESULTS: A total of 126 out of 158 ophthalmologists responded (79.7% response rate). Of the respondents, 84.9% would advise prophylactic LPI for asymptomatic PACS; 84.9% believed that prophylactic LPI would prevent acute angle closure but only 44% thought that it could prevent the development of glaucomatous optic nerve damage. The preferred method of prophylactic LPI was sequential argon-YAG LPI. In assessing patients for angle closure, 85.4% used gonioscopy, 92.9% assessed anterior chamber depth, and 17.5% performed provocative tests. CONCLUSIONS: Ophthalmologists in Singapore vary in the method of assessment of patients with angle closure. Most believe that prophylactic LPI should be performed for asymptomatic PACS.

Macular carotenoids and age-related maculopathy.

Lutein (L) and zeaxanthin (Z) are concentrated at the macula, where they are collectively known as macular pigment (MP), and where they are believed to play a major role in protecting retinal tissues against oxidative stress. Whilst the exact pathogenesis of age-related maculopathy (ARM) remains unknown, the disruption of cellular processes by oxidative stress may play an important role. Manipulation of dietary intake of L and Z has been shown to augment MP, thereby raising hopes that dietary supplementation with these carotenoids might prevent, delay, or modify the course of ARM. This article discusses the scientific rationale supporting the hypothesis that L and Z are protective against ARM, and presents the recent evidence germane to this theory.

What can patients see during glaucoma filtration surgery under peribulbar anesthesia?

PURPOSE: To describe the visual sensations experienced by patients during glaucoma filtration surgery under peribulbar anesthesia and to determine possible risk factors that may affect the visual sensations experienced. SETTING: King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia. METHODS: In this prospective questionnaire study, 75 consecutive adult patients listed for glaucoma filtration surgery (trabeculectomy or Ahmed tube implantation) under peribulbar anesthesia were interviewed postoperatively about the visual sensations experienced in their operated eye during the surgery. RESULTS: The mean age of the 75 patients was 59.7 years (range, 27 to 83, SD +/-12.1). Sixty-five patients (86.7%) perceived light perception during the surgery and the overall light intensity fluctuated in 45 patients (60.0%). The mean age of the patients who retained light perception intraoperatively was significantly lower compared with those who lost light perception (58.3 y vs. 68.8 y; P=0.009). Forty-six patients (61.3%) were able to perceive colors, 32 patients (42.7%) perceived movement, 31 patients (41.3%) saw surgical instruments, and 33 patients (44.0%) reported seeing the surgeon's hands or fingers. The severity of glaucoma did not affect the proportion of patients who perceived the various visual sensations. One patient (1.3%) was frightened by his intraoperative visual experience. Of the remaining patients, 53 (70.7%) said the visual sensations did not affect them, whereas 21 (28.0%) found them unpleasant. CONCLUSIONS: The majority of patients undergoing glaucoma filtration surgery retained light perception intraoperatively and many also experienced various visual sensations. Only 1.3% of patients were frightened by their visual experience.

Visual experiences during vitreous surgery under regional anesthesia: a multicenter study.

PURPOSE: To investigate patients' subjective intraoperative visual experiences during vitreous surgery performed under regional anesthesia, to ascertain if patients were frightened by their visual experiences, and to determine the risk factors associated with a frightening visual experience. DESIGN: Multicenter, prospective study. METHODS: Sixty-five patients who had vitreous surgery under regional (retrobulbar or peribulbar) anesthesia in five centers in Ireland, Singapore, and Hong Kong were interviewed within 2 hours of their operation using a standardized questionnaire. RESULTS: Thirty patients (46.2%) perceived light perception throughout the entire operation, 19 patients (29.2%) experienced transient loss of light perception, and 16 patients (24.6%) experienced no light perception throughout the entire duration of the surgery. Nine patients (13.8%) were frightened by their intraoperative visual experiences. Patients who were frightened by their visual experiences were more likely to see color (100%) than those who were not frightened (55.4%) (P = .010). The mean age of the patients who were frightened was lower (51.8 years) compared with those who were not frightened (64.6 years) (P = .003). The mean duration of surgery was longer for patients who were frightened (118.9 minutes) compared with those who were not frightened (91.2 minutes) (P = .047). CONCLUSIONS: Most patients undergoing vitreous surgery under regional anesthesia retained at least light perception intraoperatively. Importantly, 13.8% of patients were frightened by their visual experiences. A younger age, longer duration of surgery, and perception of color were risk factors for a frightening visual experience.

Effect of preoperative counseling on patient fear from the visual experience during phacoemulsification under topical anesthesia: Multicenter randomized clinical trial.

PURPOSE: To determine whether preoperative counseling about potential intraoperative visual experience during phacoemulsification under topical anesthesia reduces fear in patients having cataract surgery. SETTING: The Eye Institute at Tan Tock Seng Hospital, Singapore, Royal Hull Hospitals NHS Trust, Kingston-upon-Hull, and Manchester Royal Eye Hospital, Manchester, United Kingdom. METHODS: In this prospective multicenter randomized clinical trial, patients with cataracts having elective phacoemulsification under topical anesthesia were recruited and randomized into 2 groups. Both groups received routine preoperative counseling regarding risks and benefits of cataract surgery. One group received additional counseling on the potential intraoperative visual experience during phacoemulsification; the other group did not. The patients were then interviewed within 24 hours following phacoemulsification regarding their intraoperative experience. RESULTS: Two hundred nineteen patients were recruited over an 11-month period. There were 104 men and 115 women. The mean age was 68 years (range 20 to 89 years). There were 188 Singaporeans, comprising 168 Chinese, 13 Malays, and 7 Indians, and 31 British patients, all of whom were white. The mean fear score was 0.3 in the group that received additional counseling and 0.9 in the group that did not receive additional counseling (P = .036). The effect of counseling on fear was significant (P = .002) even after controlling for sex, age, and whether first or second cataract surgery. CONCLUSIONS: Preoperative counseling about the potential intraoperative visual experience during phacoemulsification under topical anesthesia helped to reduce the fear from the visual sensations in patients having cataract surgery.

Visual experiences during cataract surgery: what anaesthesia providers should know.

Recently published literature shows that most patients experience a variety of visual sensations during cataract surgery under local anaesthesia. Most patients (80-100%) retain at least some light perception in the operated eye and many also experience a variety of other visual sensations during cataract surgery under regional ophthalmic anaesthesia (retrobulbar, peribulbar and sub-Tenon's blocks) or topical anaesthesia. The visual sensations experienced include perception of movements, flashes, colours, changes in brightness, or the sight of surgical instruments, the surgeon's hands or fingers, or even the surgeon. These findings are clinically significant because 3-16.2% of patients who had cataract surgery under either regional or topical anaesthesia were frightened by their intraoperative visual experience. Fear and anxiety may cause some patients to become uncooperative during the surgery and may also induce a sympathetic stress response that might cause hypertension, tachycardia with myocardial ischaemia, hyperventilation or an acute panic attack. These effects are especially undesirable as the majority of cataract patients are elderly and have concurrent medical problems. Besides increasing the risk of intraoperative complications, a frightening visual experience may decrease patient satisfaction. Appropriate preoperative counselling has been shown to be effective in reducing the patients' fear. As most patients retain some visual function during cataract surgery under local anaesthesia, anaesthesia providers should be mindful of this phenomenon and offer appropriate preoperative information and counselling to their patients.

Visual experience during cataract surgery: a nation-wide survey on the knowledge of optometry students.

PURPOSE: Many patients experience a variety of visual sensations during cataract surgery under local anaesthesia. Up to 16.2% of patients are frightened by their intraoperative visual experience. This study aimed to determine the knowledge and beliefs of optometry students on this subject. METHODS: A nationwide survey using a standardised, self-administered questionnaire was conducted on all optometry students in Singapore. RESULTS: For cataract surgery under regional anaesthesia, 38.9% of the respondents believed that patients might experience no light perception while 68.5% felt that patients were likely to be able to perceive light. Overall, 70.4% felt that patients might be frightened by their visual experiences and 88.0% believed that preoperative counselling of patients would serve to reduce the fear experienced during the surgery. For cataract surgery under topical anaesthesia, 37.0% of the respondents believed that patients would perceive no light and 74.1% believed that patients would retain light perception. Overall, 67.6% believed that patients may be frightened and 86.1% felt that preoperative counselling would help. CONCLUSION: Many optometry students correctly believed that patients might experience a variety of visual sensations during cataract surgery under local anaesthesia. The majority were also aware that patients might be frightened by this and felt that preoperative counselling would be helpful.