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1.
BMC Med ; 20(1): 161, 2022 04 18.
Article in English | MEDLINE | ID: mdl-35430794

ABSTRACT

BACKGROUND: It is unclear whether diet affects glycaemic control in type 2 diabetes (T2D), over and above its effects on bodyweight. We aimed to assess whether changes in dietary patterns altered glycaemic control independently of effects on bodyweight in newly diagnosed T2D. METHODS: We used data from 4-day food diaries, HbA1c and potential confounders in participants of the Early-ACTivity-In-Diabetes trial measured at 0, 6 and 12 months. At baseline, a 'carb/fat balance' dietary pattern and an 'obesogenic' dietary pattern were derived using reduced-rank regression, based on hypothesised nutrient-mediated mechanisms linking dietary intake to glycaemia directly or via obesity. Relationships between 0 and 6 month change in dietary pattern scores and baseline-adjusted HbA1c at 6 months (n = 242; primary outcome) were assessed using multivariable linear regression. Models were repeated for periods 6-12 months and 0-12 months (n = 194 and n = 214 respectively; secondary outcomes). RESULTS: Reductions over 0-6 months were observed in mean bodyweight (- 2.3 (95% CI: - 2.7, - 1.8) kg), body mass index (- 0.8 (- 0.9, - 0.6) kg/m2), energy intake (- 788 (- 953, - 624) kJ/day), and HbA1c (- 1.6 (- 2.6, -0.6) mmol/mol). Weight loss strongly associated with lower HbA1c at 0-6 months (ß = - 0.70 [95% CI - 0.95, - 0.45] mmol/mol/kg lost). Average fat and carbohydrate intakes changed to be more in-line with UK healthy eating guidelines between 0 and 6 months. Dietary patterns shifting carbohydrate intakes higher and fat intakes lower were characterised by greater consumption of fresh fruit, low-fat milk and boiled/baked potatoes and eating less of higher-fat processed meats, butter/animal fats and red meat. Increases in standardised 'carb/fat balance' dietary pattern score associated with improvements in HbA1c at 6 months independent of weight loss (ß = - 1.54 [- 2.96, - 0.13] mmol/mol/SD). No evidence of association with HbA1c was found for this dietary pattern at other time-periods. Decreases in 'obesogenic' dietary pattern score were associated with weight loss (ß = - 0.77 [- 1.31, - 0.23] kg/SD) but not independently with HbA1c during any period. CONCLUSIONS: Promoting weight loss should remain the primary nutritional strategy for improving glycaemic control in early T2D. However, improving dietary patterns to bring carbohydrate and fat intakes closer to UK guidelines may provide small, additional improvements in glycaemic control. TRIAL REGISTRATION: ISRCTN92162869 . Retrospectively registered on 25 July 2005.


Subject(s)
Diabetes Mellitus, Type 2 , Blood Glucose , Body Weight , Diabetes Mellitus, Type 2/diagnosis , Glycated Hemoglobin/analysis , Glycemic Control , Humans , Weight Loss
2.
Colorectal Dis ; 22(12): 2222-2231, 2020 12.
Article in English | MEDLINE | ID: mdl-32668070

ABSTRACT

AIM: The aim was to explore whether people with an ileostomy in the UK and Ireland receive the dietary advice they require. METHOD: An online survey with multiple-choice questions asked people with an ileostomy about the dietary advice they received and would have preferred to receive. Participants were recruited via websites of the Ileostomy and Internal Pouch Association and Crohn's and Colitis UK and via social media. People with a current ileostomy, age 16 years or over, and living in the UK or Ireland were eligible for inclusion. Responses were analysed using descriptive statistics. RESULTS: In all, 291 eligible responses were received and included in the analysis; 201 (69%) received advice on diet for their ileostomy from a healthcare professional or the internet. Of the 90 who did not receive dietary advice, 82 (91%) would have liked advice. Stoma nurses were the most common source of dietary advice (55%), but many other sources were frequently reported. Most (62%) felt that at least some dietary advice they received was conflicting. Over half (55%) felt anxious about managing their diet with a new ileostomy, 39% were confused, and 31% frustrated. Of 291 respondents, 29% received advice from a dietitian compared to 60% who would have preferred advice from a dietitian. CONCLUSION: Many people undergoing ileostomy surgery do not receive the dietary advice and support they require. Healthcare professionals working with people with an ileostomy should be mindful they are often anxious about their diet and require clear and consistent dietary advice and support.


Subject(s)
Ileostomy , Surgical Stomas , Humans , Infant, Newborn , Ireland , Surveys and Questionnaires , United Kingdom
3.
Diabet Med ; 37(4): 564-572, 2020 04.
Article in English | MEDLINE | ID: mdl-31849092

ABSTRACT

AIM: To review evidence on whether diet and exercise should be used as an alternative to drug therapy for the management of type 2 diabetes or alongside. METHOD: We present a narrative review that draws on evidence from other systematic reviews and meta-analyses, narrative reviews, trials and cohort studies. We focused mainly on glycaemic control rather than control of blood pressure or cholesterol. RESULTS: Good-quality dietary advice that results in weight loss of >5% and physical activity interventions of >150 min/week of moderate to vigorous physical activity, combined with resistance exercise, can produce improvements in HbA1c similar to those produced by the addition of glucose-lowering drugs. These improvements can be seen at all stages of the disease. There are recognized interactions between glucose-lowering drugs and physical activity which may not be synergistic, but these are not well understood, and it is not clear if they are considered in clinical practice. Studies that explicitly compare drugs with diet or physical activity or control for drug use found that lifestyle could delay or reduce medication use, but most people eventually needed to progress to drug treatment. There are few studies, however, that provide strategies for the long-term maintenance of weight loss or physical activity. CONCLUSION: Diet and physical activity are of key importance in type 2 diabetes management, and attention to them improves glycaemic control and cardiovascular disease risk, but it is not yet known whether maintained lifestyle changes provide an alternative to drug therapy in the long term.


Subject(s)
Diabetes Mellitus, Type 2/therapy , Diet , Exercise/physiology , Choice Behavior , Combined Modality Therapy/methods , Diabetes Mellitus, Type 2/diet therapy , Endocrinology/organization & administration , Endocrinology/standards , Endocrinology/trends , Humans , Hypoglycemic Agents/therapeutic use , Life Style , Research/organization & administration , Research/standards , Research/trends , Risk Reduction Behavior , Societies, Medical/organization & administration , Societies, Medical/standards
4.
Diabet Med ; 2018 May 08.
Article in English | MEDLINE | ID: mdl-29738609

ABSTRACT

AIM: To explore in a feasibility study whether 'e-cycling' was acceptable to, and could potentially improve the health of, people with Type 2 diabetes. METHODS: Twenty people with Type 2 diabetes were recruited and provided with an electric bicycle for 20 weeks. Participants completed a submaximal fitness test at baseline and follow-up to measure predicted maximal aerobic power, and semi-structured interviews were conducted to assess the acceptability of using an electric bicycle. Participants wore a heart rate monitor and a Global Positioning System (GPS) receiver in the first week of electric bicycle use to measure their heart-rate during e-cycling. RESULTS: Eighteen participants completed the study, cycling a median (interquartile range) of 21.4 (5.5-37.7) km per week. Predicted maximal aerobic power increased by 10.9%. Heart rate during electric bicycle journeys was 74.7% of maximum, compared with 64.3% of maximum when walking. Participants used the electric bicycles for commuting, shopping and recreation, and expressed how the electric bicycle helped them to overcome barriers to active travel/cycling, such as hills. Fourteen participants purchased an electric bicycle on study completion. CONCLUSIONS: There was evidence that e-cycling was acceptable, could increase fitness and elicited a heart rate that may lead to improvements in cardiometabolic risk factors in this population. Electric bicycles have potential as a health-improving intervention in people with Type 2 diabetes.

5.
Eur J Clin Nutr ; 69(9): 977-1003, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25711954

ABSTRACT

The aim of this systematic review was to identify and describe brief dietary assessment tools suitable for use in clinical practice in the management of obesity, cardiovascular disease and type 2 diabetes. Papers describing development of brief (<35 items) dietary assessment questionnaires, that were accessible, simple to score and assessed aspects of the diet of relevance to the conditions of interest were identified from electronic databases. The development of 35 tools was described in 47 papers. Ten tools assessed healthy eating or healthy dietary patterns, 2 assessed adherence to the Mediterranean diet, 18 assessed dietary fat intake, and 5 assessed vegetable and/or fruit intake. Twenty tools were developed in North America. Test-retest reliability was conducted on 18 tools; correlation coefficients for total scores ranged from 0.59 to 0.95. Relative validation was conducted on 34 tools. The most common reference variable was percentage energy from fat (15 tools) and correlation coefficients ranged from 0.24, P<0.001 to 0.79, P<0.002. Tools that have been evaluated for reliability and/or relative validity are suitable for guiding clinicians when providing dietary advice. Variation in study design, settings and populations makes it difficult to recommend one tool over another, although future developers can enhance the understanding and use of tools by giving clear guidance as to the strengths and limitations of the study design. When selecting a tool, clinicians should consider whether their patient population is similar in characteristics to the evaluation sample.


Subject(s)
Cardiovascular Diseases/prevention & control , Diabetes Mellitus, Type 2/prevention & control , Diet Surveys/instrumentation , Obesity/prevention & control , Cardiovascular Diseases/diet therapy , Diabetes Mellitus, Type 2/diet therapy , Feeding Behavior , Humans , North America , Obesity/diet therapy , Reproducibility of Results
6.
BMJ Open ; 4(6): e004953, 2014 Jun 13.
Article in English | MEDLINE | ID: mdl-24928586

ABSTRACT

OBJECTIVES: Describe dietary intake of participants enrolled in a non-prescriptive dietary intervention and dietary changes at 6 months and explore whether these changes had a role in observed improvements in glycated haemoglobin (HbA1c), weight, lipids and blood pressure. DESIGN: Secondary analysis of data from the Early ACTivity in Diabetes randomised controlled trial. PARTICIPANTS: 262 patients with newly diagnosed type 2 diabetes randomised to the dietary intervention. OUTCOMES AND ANALYSIS: Changes in energy intake, macronutrients, fibre and alcohol and in weight, waist circumference, lipids, HbA1c and blood pressure at baseline and 6 months. Multivariate models were used to examine associations between dietary changes and metabolic variables. RESULTS: Men reported reducing mean energy intake from 1903±462 kcal to 1685 kcal±439 kcal (p<0.001), increasing carbohydrate intake from 42.4±6.6% to 43.8±6.6% (p=0.002) and reducing median alcohol intake from 13 (0-27) g to 5 (0-18) g (p<0.001). Women reported reducing mean energy intake from 1582±379 kcal to 1459±326 kcal (p<0.001) with no change to macronutrient distribution and alcohol. Fibre intake was maintained. In men (n=148), weak and clinically insignificant associations were found between increased carbohydrates and reduction in HbA1c (ß=-0.003 (-0.006, -0.001); p=0.009), increased fibre and reduction in total cholesterol (ß=-0.023 (-0.044, -0.002); p=0.033), decreased total fat and reduction in low-density lipoprotein (LDL)-cholesterol (ß=0.024 (0.006, 0.001); p=0.011), and decreased alcohol and reduction in diastolic blood pressure (ß=0.276 (0.055, 0.497); p=0.015). In women (n=75), associations were found between a decrease in transfats and reductions in waist circumference (ß=-0.029 (0.006, 0.052); p=0.015), total cholesterol (ß=0.399 (0.028, 0.770); p=0.036) and LDL cholesterol (ß=0.365 (0.042, 0.668); p=0.028). CONCLUSIONS: Clinically important metabolic improvements observed in a patient-centred dietary intervention were not explained by changes in macronutrients. However, a non-prescriptive approach may promote a reduction in total energy intake while maintaining fibre consumption. TRIAL REGISTRATION NUMBER: The Early ACTID trial number ISRCTN92162869.


Subject(s)
Diabetes Mellitus, Type 2/diet therapy , Feeding Behavior , Patient-Centered Care , Female , Humans , Male , Middle Aged
7.
J Hum Nutr Diet ; 27(4): 311-21, 2014 Aug.
Article in English | MEDLINE | ID: mdl-23980910

ABSTRACT

OBJECTIVES: There is a lack of published data about the food intake of patients with type 2 diabetes and the changes that they make in response to patient-centred dietary advice. The present study describes the changes reported in response to a nonprescriptive dietary intervention based upon UK dietary guidelines. METHODS: Two hundred and sixty-two patients (87 women and 175 men) from the Early ACTivity in Diabetes (ACTID) trial who received the dietary intervention returned 4 days food diaries at baseline and 6 months. Nonparametric tests were used to examine changes in meal patterns, total energy intake and energy from food groups between baseline and 6 months. RESULTS: Mean (SD) number of reported meals day(-1) was 3.0 (0.3) and mean (SD) number of snacks was 1.1 (0.6) at both baseline and 6 months for men and women. Men reported decreasing energy intake by a mean (SD) of 912 (1389) KJ/day [218 (332) kcal day(-1) ] (P < 0.001) and women by 515 (1130) KJ/day [123 (270) kcal day(-1) ] (P < 0.001). Men reported reducing energy from alcoholic drinks [-234 (527) KJ day(-1) ; P < 0.001], white bread [-113 (402) KJ day(-1) ; P = 0.001], biscuits [i.e. cookies -67 (205) KJ day(-1) ; P < 0.001] and cakes [-50 (410) KJ day(-1) ; P = 0.0012]. Women reported reducing energy from mixed main meals [-134 (456) KJ day(-1) ; P = 0.036], pasta and rice [-79 (326) KJ day(-1) ; P = 0.019], high-energy drinks [-59 (159) KJ day(-1) ; P = 0.001] and white bread [-59 (368) KJ day(-1) ; P = 0.042]. CONCLUSIONS: Men and women in the Early ACTID study reported small changes in higher-energy and lower-fibre foods and drinks in response to patient-centred dietary advice.


Subject(s)
Diabetes Mellitus, Type 2/diet therapy , Diet Records , Feeding Behavior , Aged , Dietary Fiber/administration & dosage , Energy Intake , Female , Humans , Male , Meals , Middle Aged , Nutrition Policy , United Kingdom
8.
Lancet ; 378(9786): 129-39, 2011 Jul 09.
Article in English | MEDLINE | ID: mdl-21705068

ABSTRACT

BACKGROUND: Lifestyle changes soon after diagnosis might improve outcomes in patients with type 2 diabetes mellitus, but no large trials have compared interventions. We investigated the effects of diet and physical activity on blood pressure and glucose concentrations. METHODS: We did a randomised, controlled trial in southwest England in adults aged 30-80 years in whom type 2 diabetes had been diagnosed 5-8 months previously. Participants were assigned usual care (initial dietary consultation and follow-up every 6 months; control group), an intensive diet intervention (dietary consultation every 3 months with monthly nurse support), or the latter plus a pedometer-based activity programme, in a 2:5:5 ratio. The primary endpoint was improvement in glycated haemoglobin A(1c)(HbA(1c)) concentration and blood pressure at 6 months. Analysis was done by intention to treat. This study is registered, number ISRCTN92162869. FINDINGS: Of 593 eligible individuals, 99 were assigned usual care, 248 the diet regimen, and 246 diet plus activity. Outcome data were available for 587 (99%) and 579 (98%) participants at 6 and 12 months, respectively. At 6 months, glycaemic control had worsened in the control group (mean baseline HbA(1c) percentage 6·72, SD 1·02, and at 6 months 6·86, 1·02) but improved in the diet group (baseline-adjusted difference in percentage of HbA(1c) -0·28%, 95% CI -0·46 to -0·10; p=0·005) and diet plus activity group (-0·33%, -0·51 to -0·14; p<0·001). These differences persisted to 12 months, despite less use of diabetes drugs. Improvements were also seen in bodyweight and insulin resistance between the intervention and control groups. Blood pressure was similar in all groups. INTERPRETATION: An intensive diet intervention soon after diagnosis can improve glycaemic control. The addition of an activity intervention conferred no additional benefit. FUNDING: Diabetes UK and the UK Department of Health.


Subject(s)
Diabetes Mellitus, Type 2/therapy , Adult , Aged , Aged, 80 and over , Combined Modality Therapy , Diabetes Mellitus, Type 2/diet therapy , Exercise Therapy , Female , Health Behavior , Humans , Intention to Treat Analysis , Life Style , Male , Middle Aged , Weight Loss
9.
J Hum Nutr Diet ; 17(6): 547-59, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15546433

ABSTRACT

BACKGROUND: The Internet may be a useful resource for people with coeliac disease as a great deal of health-related information is published online. However, not all of it is accurate. It has been suggested that accurate information is most likely found on transparent sites and kitemarks are awarded on this basis. This paper examines whether the Internet is a useful resource for people with coeliac disease and whether transparency criteria can be used in identifying accurate sites. METHOD: An evaluation tool was developed using selected transparency criteria and clinical guidelines for accuracy. A total of 63 websites were evaluated. RESULTS: In the study, 66% of the websites scored less than 50% for accuracy. This was primarily because of incomplete information but 15.9% of sites contained inaccuracies. Over 50% of sites scored less than 50% for transparency. No correlation was found between sites that scored highly for accuracy and those that scored highly for transparency. CONCLUSION: There are useful information available for people with coeliac disease but transparency criteria alone cannot be used to identify accurate sites.


Subject(s)
Celiac Disease/therapy , Internet , Patient Education as Topic/methods , Patient Education as Topic/standards , Humans , Information Dissemination/methods , Internet/standards
11.
Ann Anat ; 179(3): 245-54, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9229078

ABSTRACT

A Nd:YAG laser scalpel was used for the surgical reduction of a human hyperplastic tongue. This instrument combines a fine cutting precision with haemostatic properties, whereby loss of blood is minimized and the surgeon's field of view unimpeded by flooding from the damaged capillary bed. The coagulative properties of Nd:YAG laser light are, however, insufficient to effect blood flow stasis in larger calibre vessels (arteries > 2 mm; veins > 3-5 mm), such as those located at the base of the tongue. For this purpose, bipolar diathermy (electrocautery) was employed. The ultrastructural changes incurred by skeletal muscle fibres using these two "heat" sources were compared. The damage profile elicited using each modality was similar: coagulation of myofilamentous proteins leads to destruction of fibrillar architecture with concomitant loss of periodic banding; on moving away from the wound margin, characteristic features are gradually restored. As the severity of these heat-induced effects decreases, there is a corresponding increase in superimposed dislocation and tearing phenomena induced by post-treatment swelling.


Subject(s)
Laser Therapy/methods , Tongue/surgery , Adult , Electrocoagulation/adverse effects , Humans , Hyperplasia/surgery , Laser Therapy/adverse effects , Muscle, Skeletal/anatomy & histology
12.
Exp Eye Res ; 64(6): 1013-26, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9301483

ABSTRACT

The precise mechanism whereby mitomycin C enhances IOP reduction in glaucoma filtering surgery still eludes us. Ten rabbits received full-thickness Nd:YAG laser sclerostomy ab interno and adjunctive intraoperative treatment with mitomycin C (MMC) applied topically over the intact conjunctiva (0.5 mg ml-1 for 5 min). A systematic ultrastructural analysis of the fistulas and surrounding tissue was then conducted in conjunction with clinical observations, over the ensuing 10 weeks. In order to investigate also the extent to which MMC impedes fistula occlusion in the absence of percolating aqueous humour, we created non-perforating ('half-thickness') sclerostomies ab interno in three additional rabbits, one with and two without MMC therapy. Transconjunctival MMC application resulted in no serious complications. Eight of the ten full-thickness fistulas remained patent throughout the study, maintaining significant IOP reduction; the other two sclerostomies were compromised by iris incarceration. The MMC-treated, half-thickness canal remained as a tissue-free cul de sac; the two non-treated ones became completely occluded within one week without having recourse to extraocular cell populations. MMC suppressed the migration and proliferation of fibroblasts, macrophages and clump cells from the episclera, sclera, ciliary body and iris root. Repolymerization of heat-damaged collagen was abortive; neosynthesis was not observed. Myofibroblasts were encountered in the vicinity of the sclerostomy canals, and, after the fifth week, these cells were also found to be deployed as a canal-lining layer, delimiting the lumen from the surrounding stroma along most of the fistula length. Towards the external ostium, this layer of myofibroblasts was incomplete or absent. Near the internal ostium, lining cells were derived from the corneal endothelium. The transconjunctival mode of applying MMC appears to be efficient. This antifibrotic drug exerts its inhibitory influence by suppressing not only cell migration and proliferation, but also phagocytic and synthetic activities. However, exposed tissues are not acellular, and amongst the populations present, myofibroblasts are found to dominate the scene. The canal-delimiting cellular lining may play a role in maintaining fistula patency in MMC-treated eyes.


Subject(s)
Laser Therapy , Mitomycin/pharmacology , Nucleic Acid Synthesis Inhibitors/pharmacology , Sclerostomy , Wound Healing/drug effects , Administration, Topical , Animals , Collagen/drug effects , Glaucoma/surgery , Intraoperative Care , Microscopy, Electron , Postoperative Period , Rabbits , Sclera/ultrastructure
13.
Eur J Ophthalmol ; 7(1): 24-8, 1997.
Article in English | MEDLINE | ID: mdl-9101191

ABSTRACT

UNLABELLED: The course of tissue repair evoked by Nd:YAG laser sclerostomy ab interno and the effect of mitomycin-C on same were investigated ultrastructurally in 15 rabbits. In ten of them, the dynamics of the spontaneous postoperative healing response (i.e. in the absence of medication) was analyzed at two-day intervals by light- and electron microscopy. In two, fibroblast activity was assessed autoradiographically. In the last three rabbits, the sclerostomy site was exposed transconjunctivally to mitomycin-C (0.5 mg/ml; 5 minutes) before surgery, and morphological analysis was done on postoperative days 6 and 12. RESULTS: In the spontaneously healing group, blebs disappeared within five days of surgery. This corresponded to a massive invasion of macrophages and fibroblasts from the episclera and iris root. The sheath of coagulated tissue around the fistula appeared to act as a barrier to cell migration from the sclera itself at this stage. By days 8 to 12, the canal had become occluded by a network of cells and capillaries, and collagen fibrils in the coagulation sheath had undergone repolymerization. In the mitomycin-C group, large filtering blebs and patent, cell-free fistulas were observed over the entire period. Although applied transconjunctivally, the drug penetrated the whole scleral depth, as the iris root and ciliary body cell reaction was inhibited. Repolymerization of heat-damaged collagen was also hindered. The overall findings provide information on the sequence of repair events following laser sclerostomy. Local, non-invasive application of mitomycin-C delays the onset of this process, not only by inhibition of cell proliferation but also by suppressing the collagen recovery.


Subject(s)
Antibiotics, Antineoplastic/pharmacology , Laser Therapy , Mitomycin/pharmacology , Sclera/pathology , Sclerostomy/methods , Wound Healing , Animals , Cell Division , Cell Movement , Chemotherapy, Adjuvant , Fibroblasts/pathology , Fibroblasts/ultrastructure , Follow-Up Studies , Macrophages/pathology , Macrophages/ultrastructure , Rabbits , Sclera/drug effects , Sclera/surgery , Wound Healing/drug effects
14.
Technol Health Care ; 4(4): 425-9, 1996 Dec.
Article in English | MEDLINE | ID: mdl-9042693

ABSTRACT

One may consider the clad silica fibre cutting probe as a cheap alternative of the popular sapphire probe, sharing some of its properties. Made of silica, the scalpels have a fair heat tolerance and may be used without cooling by liquids or gas as is necessary with sapphire blades. The laser scalpel described here is driven (powered) with a 10 W cw Nd:YAG laser energy source (1064 nm) and possesses good cutting and haemostatic properties. It may also be used with lasers emitting other wavelengths. One may assume that a diode laser emitting in the near infrared (800-810 nm) may have very similar, although no analogous cutting properties when used with the described scalpel.


Subject(s)
Laser Therapy/instrumentation , Equipment Design , Humans , Silicon Dioxide
15.
Exp Eye Res ; 61(3): 311-21, 1995 Sep.
Article in English | MEDLINE | ID: mdl-7556495

ABSTRACT

This study was undertaken to examine ultrastructurally the course of tissue regeneration after thermally-induced laser sclerostomy and compare it with the post-operative clinical events in a rabbit model. Applying a continuous wave neodymium:YAG (Nd:YAG) laser, two sclerostomies were created ab interno on one eye in each of ten pigmented rabbits using a 200-microns-diameter quartz optical fiber; the unoperated fellow-eyes served as controls. Intraocular pressure (IOP) was measured daily before and after surgery. Animals were observed post-operatively for up to 16 days. Well-defined filtering blebs and a low complication rate demonstrated the success of the procedure. IOP was significantly lowered during the entire course of the observation period but after the fifth day, the conjunctival blebs had disappeared. The morphology of the changes in the sclerostomy fistulas were analysed at 2-day intervals by light and electron microscopy. Immediately after surgery, the canal was ensheathed by an approximately 100-microns-thick layer of coagulated collagenous tissue in which two zones could be distinguished according to the intensity of damage. Within 5 days, the inner and outer canal openings were invaded by macrophages and fibroblasts originating from the iris root and episclera, respectively. The former cells were engaged in the phagocytosis of disintegrated collagen adjacent to the lumen. More distally located fibrils which had incurred less severe damage, had retained their fibrillar structure but had lost banding periodicity. After thermal stress had faded, they appeared to undergo a process of repolymerisation. By day 10, the lumen had become occluded by a loose meshwork of phagocytes, fibroblasts and proliferating capillaries. These new vessels and the loose nature of the canal-occluding framework and of the surrounding regenerating collagenous tissue could have further permitted percolation and transport of aqueous humor, since IOP remained low, despite the disappearance of filtering blebs. Although the time course of repair is more rapid in rabbits than in humans, the data gleaned nonetheless yield valid information respecting the sequence of events following thermally-induced scleral fistula.


Subject(s)
Laser Therapy , Sclerostomy , Wound Healing , Animals , Collagen/ultrastructure , Fibroblasts , Intraocular Pressure , Macrophages , Microscopy, Electron , Rabbits , Sclera/ultrastructure , Time Factors
16.
Eur J Ophthalmol ; 5(3): 160-7, 1995.
Article in English | MEDLINE | ID: mdl-8845683

ABSTRACT

Baso-cellular carcinomas involving the medial canthal regions of both eyes were resected using a 10 W cw-Nd: YAG laser scalpel. The wound bed was repaired one side by a free, split-thickness graft and on the other by a frontal pedicle flap. Surgery was, for the most part, virtually bloodless. Since laser radiation immediately seals both capillaries and lymphatics, the incidence of postoperative hemorrhage and edema was significantly less than after cold scalpel surgery. Healing was uneventful. The advantages of laser-assisted surgery are worthy of consideration: not only is the operation time markedly curtailed, but the wound healing response is excellent, with only a minimal inflammatory reaction.


Subject(s)
Carcinoma, Basal Cell/surgery , Eyelid Neoplasms/surgery , Laser Therapy/methods , Skin Neoplasms/surgery , Surgery, Plastic/methods , Aged , Carcinoma, Basal Cell/pathology , Eyelid Neoplasms/pathology , Female , Hemostasis , Humans , Laser Therapy/instrumentation , Skin Neoplasms/pathology , Skin Transplantation , Surgical Flaps , Transplantation, Autologous , Wound Healing
17.
Br J Ophthalmol ; 79(7): 672-7, 1995 Jul.
Article in English | MEDLINE | ID: mdl-7662634

ABSTRACT

AIMS: This study was carried out to compare the effects of continuous wave infrared laser radiation on pigmented and albino rabbit retinas at two wavelengths: 810 nm (diode) and 1064 nm (Nd:YAG). METHODS: Transpupillary laser pulses were applied with a spot size of 200 microns and durations of 200 ms (pigmented rabbits) and 0.5-1 s (albino rabbits). Light and electron microscopic analyses were performed immediately after exposure. RESULTS: In pigmented rabbits, threshold lesions were induced using a power of 100 mW with the diode and 200 mW with the Nd:YAG lasers. Damage was incurred by the retinal pigment epithelium with extension into the superficial and mid choroid posteriorly and into the outer retina anteriorly. In albino rabbits, lesions of comparable anteroposterior extension were identified using a power of 10 W with the Nd:YAG laser. Using diode laser irradiation, a maximum power output of 1.2 W failed to produce discernible lesions. CONCLUSIONS: The observed patterns of morphological damage are produced by complex tissue radiation interactions. In pigmented animals, this was primarily related to absorption of radiant energy by melanin within the retinal pigment epithelium and the choroidal melanocytes. In albino rabbits, laser induced effects occurred as a consequence of multiple scattering, together with absorption within haemoglobin and possibly also within tissue water. The data obtained provide further insight into the biological mechanisms arising from retinal photocoagulation with near infrared lasers.


Subject(s)
Albinism, Ocular , Infrared Rays , Laser Coagulation , Retina/radiation effects , Acute Disease , Albinism, Ocular/pathology , Animals , Choroid/chemistry , Choroid/radiation effects , Choroid/ultrastructure , Melanins/radiation effects , Pigment Epithelium of Eye/chemistry , Pigment Epithelium of Eye/radiation effects , Pigment Epithelium of Eye/ultrastructure , Rabbits , Retina/ultrastructure
18.
Ger J Ophthalmol ; 4(1): 7-10, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7728114

ABSTRACT

Sclerostomy fistulas were created ab interno in cadaver porcine eyes by an active contact method using a 200-microns-diameter silica optical fiber in conjunction with either Ho:YAG-, Nd:YAG-, or diode-laser light, and a qualitative comparison of the degree of collateral thermal damage induced in each case was undertaken at the light and electron microscopic levels. The apparent breadth of coagulated tissue observed in association with cross-sectioned fistula profiles exhibited considerable local variation, irrespective of the radiation source employed; no intrinsic difference in either the intensity or the extent of the thermal insult incurred was noted between the three laser modalities.


Subject(s)
Laser Therapy/methods , Sclerostomy , Animals , Ostomy/methods , Sclera/pathology , Sclera/surgery , Swine
19.
Klin Monbl Augenheilkd ; 204(5): 290-1, 1994 May.
Article in German | MEDLINE | ID: mdl-8051853

ABSTRACT

METHODS: A number of ab interno and ab externo sclerostomy procedures have been described in recent years. CONCLUSION: At the present time, there is no clear indication that such interventions are superior to the classical fistulizing glaucoma operations, such as trabeculectomy.


Subject(s)
Glaucoma, Open-Angle/surgery , Sclerostomy , Follow-Up Studies , Humans , Postoperative Complications/etiology , Treatment Outcome
20.
Klin Monbl Augenheilkd ; 204(5): 427-9, 1994 May.
Article in German | MEDLINE | ID: mdl-8051891

ABSTRACT

The effects of Ho:YAG- (free-running mode), Nd:YAG- (continuous wave mode) and diode- (continuous wave mode) laser radiation on the degree of collateral thermal damage realized during the creation of sclerostomy canals ab interno (by an active contact method) were compared morphologically: Both the nature and extent of coagulation occurred by scleral collagen fibrils were found to be independent of the laser modality employed.


Subject(s)
Laser Therapy/instrumentation , Sclera/pathology , Sclerostomy/instrumentation , Animals , Collagen/ultrastructure , Microscopy, Electron, Scanning , Sclera/injuries , Swine
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