[Studying the regression pattern of stage II and III retinopathy of prematurity by means of morphometric analysis of retinal vessels in different terms after laser retinal photocoagulation].

Dynamic evaluation of the diameters of central fundus vessels, 2nd order and peripheral vessels as well as the tortuosity index of central zone arteries in stage II and III retinopathy of prematurity (ROP), which showed regression after laser treatment, was performed. Obtained data can be used for estimation of the optimal follow-up period ensuring early detection of high probability for ROP progression after laser coagulation and decrease of the number of diagnostic examinations for patients whose pathologic process is resolving.

Placental histopathological features of fetoscopic laser photocoagulation for monoaminotic diamniotic twin pregnancies.

INTRODUCTION: This study aimed to compare the histopathological placental features of monochorionic diamniotic (MCDA) twins who did and did not undergo fetoscopic laser photocoagulation (FLP). METHODS: This was a retrospective single-institution cohort study on MCDA twins who underwent FLP between October 2010 and December 2018. The control group included MCDA twins who did not undergo FLP and were delivered during the same period in the institute. The incidence of chorioamnionitis (CAM), funisitis, and other pathological findings was compared between the FLP and control groups after matching by gestational age at delivery. RESULTS: In total, 292 MCDA pregnant women who underwent FLP and 356 controls gave birth during the study period. After matching the two groups in the ratio 1:1 by gestational age at delivery, each group comprised 194 subjects. The incidence of histological CAM with Blanc association (stage I, 6.2% vs. 3.1%, crude odds ratio (cOR) = 3.1, P = 0.052; stage II, 7.2% vs. 5.7%, cOR = 1.6, P = 0.30; stage III, 2.1% vs. 2.6%, cOR = 0.66, P = 0.52) and funisitis (artery, 5.2% vs. 3.6%, cOR = 1.3, P = 0.63; vein 7.2% vs. 4.1%, cOR = 1.6, P = 0.29) was not statistically significant difference between the FLP and control groups. The FLP group demonstrated a higher incidence of partial placental infarction than the control group (10.3% vs. 3.1%, cOR = 4.3, P = 0.004, adjusted OR = 2.8, P = 0.031). DISCUSSION: FLP did not appear to increase the incidence of histological CAM or funisitis in subjects matched by gestational age at delivery. The FLP group demonstrated a higher incidence of partial placental infarction than the control group.

[Central and branch retinal vein occlusion. Current strategies for treatment in Germany, Austria and Switzerland]. / Retinale Zentralvenen- und Venenastverschlüsse: Aktueller Therapiestand in Deutschland, Osterreich und der Schweiz.

BACKGROUND: The main object of this study was to find out what treatment methods are currently preferred for central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) in Germany, Austria and Switzerland. METHODS: A questionnaire concerning the different medicamentous, surgical and laser treatments available for CRVO and BRVO was developed and sent out to the members of the German Retina Society. RESULTS: This analysis is based on 124 returned questionnaires. We found that 64% of our colleagues recommend isovolemic hemodilution in patients with CRVO. Pentoxyfyllin infusions are endorsed by 32% and 27%, respectively, for CRVO and BRVO. Panretinal photocoagulation is applied only if neovascularization is present by 39% of those responding, whereas 61% perform prophylactic photocoagulation when there is no visible neovascularization, depending on the degree of ischemia. In the case of macular edema due to BRVO 52% recommend macular grid photocoagulation. Sheathotomy is recommended by 51% for BRVO suggest, and 43% advise radial optic neurotomy (RON) for CRVO. Intravitreal injection of triamcinolone is performed for CRVO or BRVO by 58% and 56%, respectively, and para-bulbar injection of triamcinolone by 2% and 3%. Intravitreal anti-VEGF treatment is applied by 72% of respondents, the majority (94%) using bevacizumab for this purpose. CONCLUSION: Members of the German Retina Society apply widely differing treatments in patients with CRVO and BRVO. Further clinical studies to evaluate the different therapeutic options seem necessary in order to set up guidelines for the treatment of venous retinal occlusions.

A comparative study of panretinal photocoagulation and vitrectomy for advanced diabetic retinopathy.

A retrospective, cohort study of patients with diabetic retinopathy was conducted, which assessed factors of age at the time of initial panretinal photocoagulation, sex, race [American Indian and non-Indian), and those requiring postpanretinal photocoagulation vitrectomy. Frequency analyses were used to categorize the study population by ethnicity and sex. Independent sample Student's t test were used to compare means of age, ethnicity, and sex. Layered chi2 analyses were performed to study the ethnic status of the men and women requiring vitrectomy, followed by an examination of the relationship of these three factors to the vitrectomy group using a logistic regression model. Within this 265 patient group, the American Indian male was noted to require vitrectomy more frequently and tended to receive initial panretinal phototcoagulation at a lower age.

[The effects of photocoagulation on the electrical activity of the diabetic retina]. / Consecintele fotocoagularii asupra activitatii electrice a retinei diabetice.

The aim of photocoagulation in diabetic retinopathy is to destroy ischaemic retina because this produces a vasogenic factor, responsible of neovascularization. Retinal burn reduces the number of photoreceptors and effects the transmission of nervous impulse in areas close to those coagulated. It is presumable therefore that electroretinographic parameters will be significantly modified after treatment. 23 diabetic patients where investigated, resulting 43 scotopic electroretinograms, 41 photopic electroretinograms and 46 flicker electroretinograms, each eye being considered separately. The statistic analysis showed significant alterations with laser treatment of the amplitudes of a and b waves in both scotopic and photopic conditions as well as diminished amplitude of the flicker test.

Pre-eclampsia and pregnancy-induced hypertension are associated with severe diabetic retinopathy in type 1 diabetes later in life.

To investigate whether pre-eclampsia (PE) or pregnancy-induced hypertension (PIH) predicts the development of severe diabetic retinopathy (SDR) in type 1 diabetes. Altogether, 203 women with type 1 diabetes who were followed during pregnancy were re-examined within the Finnish Diabetic Nephropathy Study. After excluding patients with pre-pregnancy hypertension and those who had had laser treatment or whose retinopathy was graded as proliferative at the index pregnancy, 158 were prospectively studied. As a surrogate marker for SDR, retinal laser photocoagulation was used. The time from pregnancy to SDR (N = 21) or follow-up was 16 years (interquartile range, 11-19). HbA1c was repeatedly measured both during pregnancy and follow-up. Women with prior PE (26 % vs. 6 %, P = 0.003) or PIH (24 % vs. 6 %, P = 0.008) had more often incident SDR during follow-up compared to those with normotensive pregnancy. The hazard ratios (HR) remained associated with the progression to SDR after adjustment for duration of diabetes and diabetic nephropathy in a Cox regression analysis [PE: 3.5 (95 % CI 1.1-10.9); P = 0.03 and for PIH: 3.2 (1.1-9.8); P = 0.04]. The association between PIH and incident SDR did not change after inclusion of mean HbA1c, measured during pregnancy (all 3 trimesters) and serial HbA1c measurements during follow-up, 3.5 (1.1-11.8; P = 0.03). However, in a similar model, the HR for PE was no more significant 2.0 (0.6-6.8; P = NS). The results suggest that women with type 1 diabetes and a hypertensive pregnancy have an increased risk of severe diabetic retinopathy later in life.

Retinoblastoma: geographic distribution and presentation at a tertiary eye care centre in Kathmandu, Nepal.

INTRODUCTION: Several aspects of retinoblastoma in Nepal remain enigmatic. OBJECTIVE: To assess the demographic and geographic distribution, clinical presentation, and treatment methods of retinoblastoma at a tertiary level ophthalmic institution in Kathmandu, Nepal. MATERIALS AND METHODS: A retrospective analysis of all the patients diagnosed with retinoblastoma at Tilganga Institute of Ophthalmology from July 2004 to June 2008 was performed. The main outcome measures included region of residence, treatment options and histopathological findings. The histopathological analysis was performed on enucleated and exenterated specimens. STATISTICS: The statistical analysis was performed with SPSS Version 11.5. Descriptive statistics are represented as mean ± standard deviation. All tests were two-sided and the P-values of less than 0.05 were considered statistically significant. RESULTS: Thirty patients presented with retinoblastoma during the study period. The mean age at presentation was 2.5 ± 1.6 years (range five months to seven years). Ten of the 12 patients who presented with bilateral retinoblastoma (83 %) were from the Terai region of Nepal. The ratio of unilateral to bilateral cases in the Terai region was 1:2. This differed significantly with the ratio in the hilly region (Fisher's Exact Test, p = 0.0012). The mean duration of symptoms before presentation was 2.5 3.2 months (range three days to 12 months). Twenty-four patients (80 %) presented with leukocoria. Eleven patients (36.6 %) presented with leukocoria as their only symptom. Ninety-seven percent of the patients underwent either enucleation (90 %) or exenteration (6.7 %) of at least one eye. CONCLUSION: Bilateral retinoblastoma is more prevalent in the Terai region of Nepal. The majority of the patients present with leucokoria and are treated with enucleation.

[Efficacy of vitreorretinal surgery to improve best corrected visual acuity in diabetics with retinopathy]. / Eficacia de la cirugía vitreorretiniana para mejorar la capacidad visual en diabéticos con retinopatía.

BACKGROUND: complications of proliferative diabetic retinopathy require surgical treatment. In 2007 Flaxel reported visual improvement after vitreoretinal surgery in 37% of Latino diabetics; in our country it is estimated that a higher proportion of patients improves, but this has not been documented. AIM: to identify the efficacy of vitreoretinal surgery for improving best corrected visual acuity, in diabetic patients treated at a hospital in Mexico City. METHODS: an observational, longitudinal, retrospective, descriptive study was conducted in diabetics who underwent vitreoretinal surgery (2007-2010) with one year follow-up. Visual acuity was measured before surgery and one year after, and it was registered when the retinopexy orphacoemulsification was performed, or silicone tamponade wasused. The proportions and 95% confidence intervals (CI) of patients whose visual acuity improved, did not change or worsened, were compared with those reported by Flaxel in Latino patients (χ(2), relative risk [RR]). RESULTS: 63 patients, mean age 58.5 ± 11.6 years, 26 with retinal detachment (41.3%), phacoemulsification was performed in 50 (79.4%), and silicone was used in 27 (42.9%). BCVA worsened in 12 patients (19%), did not change in 5 (8%) and improved in 46 (73%, 95% CI 62-84); the latter proportion exceeded that reported by Flaxel (p = 0.0005, RR 1.97, 95% CI 1.25-3.1). DISCUSSION: although the difference was not clinically significant, the efficacy of vitreoretinal surgery to improve visual acuity in the sample was consistently higher than that reported by Flaxel in Latinos, and did not vary from other studies. These results do not support an association between an ethnic group and a lower surgical efficacy.

Practice patterns of Canadian vitreoretinal specialists in diabetic macular edema treatment.

OBJECTIVE: To establish the practice patterns of Canadian vitreoretinal (VR) specialists in the treatment of diabetic macular edema (DME). DESIGN: A survey was mailed, faxed, e-mailed, and published online for access by all Canadian VR specialists. PARTICIPANTS: All VR specialists identified from the Canadian Ophthalmology Society directory and the Canadian Retina and Vitreous Society directory. METHODS: A 19-item survey investigating treatment of DME was mailed to all VR specialists. A reminder fax and e-mail was sent with the survey attached. In all correspondence, physicians were given information regarding an available online version of the survey. The survey data was descriptively analyzed with the Statistical Package for the Social Sciences. RESULTS: With clinically significant macular edema (CSME) that is either away from the foveal avascular zone (FAZ) or diffuse, the most common first-line treatment option was macular photocoagulation 48 (78.8%) and 33 (54.1%), respectively. For microaneurysms within the FAZ, 33 (54.1%) of respondents chose intravitreal antivascular endothelial growth factor agents as their first-line treatment. In all, 51 respondents (83.6%) felt that vitrectomy played a role in the management of treatment-resistant CSME. Before utilizing intravitreal triamcinolone acetonide (IVT) injections, 34 (55.7%) of respondents did use a topical steroid trial to look for raised intraocular pressure whereas 16 (26.2%) of respondents did not use IVT injections at all. CONCLUSIONS: This survey provides valuable practical information on how DME is currently being treated in Canada and may serve as a baseline to assess how these patterns evolve over time.

Rates of progression in diabetic retinopathy during different time periods: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis reviews rates of progression of diabetic retinopathy to proliferative diabetic retinopathy (PDR) and/or severe visual loss (SVL) and temporal trends. RESEARCH DESIGN AND METHODS: This systematic literature review and meta-analysis of prospective studies assesses progression of retinopathy among diabetic patients without treatment for retinopathy at baseline. Studies published between 1975 to February 2008 were identified. Outcomes of interest were rates of progression to PDR and/or SVL. Pooled baseline characteristics and outcome measures were summarized using weighted averages of counts and means. Baseline characteristics and outcomes were compared between two periods: 1975-1985 and 1986-2008. RESULTS: A total of 28 studies comprising 27,120 diabetic patients (mean age 49.8 years) were included. After 4 years, pooled incidence rates for PDR and SVL were 11.0 and 7.2%, respectively. Rates were lower among participants in 1986-2008 than in 1975-1985. After 10 years, similar patterns were observed. Participants in 1986-2008 studies had lower proportions of PDR and non-PDR at all time points than participants in 1975-1985 studies. CONCLUSIONS: Since 1985, diabetic patients have lower rates of progression to PDR and SVL. These findings may reflect an increased awareness of retinopathy risk factors; earlier identification and initiation of care for patients with retinopathy; and improved medical management of glucose, blood pressure, and serum lipids. Differences in baseline characteristics, particularly in the prevalence and severity of retinopathy, could also have contributed to these temporal differences.

[The outpatient management of internal hemorrhoids by infrared photocoagulation]. / El manejo ambulatorio de la hemorroide interna con fotocoagulación infrarroja.

Infrared photocoagulation is a new ambulatory therapy for 1st, 2nd and 3rd degree internal hemorrhoids. It is an effective method, comparable to others such as sclerotherapy or rubber band ligature. It is necessary to use multiple applications in several sessions in order to obtain good results. Patients with hemorrhoids grade IV are candidates for hemorrhoidectomy. The author did not observe minor nor serious complications with this new therapeutic modality. It is fast and easy to use by a single operator. The equipment is portable, easy to handle and long lasting, needing little maintenance. The anatomical results suggest that the progression of hemorrhoids and also, probably, surgery are prevented. Long-term follow up is necessary.

The efficacy and safety of argon plasma coagulation therapy in Barrett's esophagus.

BACKGROUND: Thermoablation is being used to eliminate the metaplastic epithelium of Barrett's esophagus and allow its reversal into squamous epithelium in an acid-controlled environment. This study assessed the efficacy and safety of a new thermoablation technique, argon plasma coagulation. METHODS: Patients with circumferential Barrett's esophagus 2 to 5 cm long were enrolled. Acid suppression was accomplished with lansoprazole. One-half the circumference of Barrett's mucosa was treated with argon plasma coagulation, and the other half served as an internal control. After macroscopic squamous re-epithelialization occurred, biopsy specimens were obtained from both areas systematically. RESULTS: Nine patients, all men with a mean age of 51.1 years, completed the study. During 24-hour esophageal pH monitoring a pH less than 4 occurred on average 2.8% of the time with a mean dose of lansoprazole of 70 mg/day. Squamous re-epithelialization developed in treated areas in all 9 patients. Biopsy showed that 7 of 9 patients (77.8%) had squamous re-epithelialization without intestinal metaplasia. Biopsy showed that 2 of 9 patients (22.2%) had squamous re-epithelialization with evidence of underlying intestinal metaplasia. There were no serious complications. CONCLUSIONS: Argon plasma coagulation in an acid-controlled environment was both efficacious and safe in the treatment of Barrett's esophagus. However, the reappearance of squamous epithelium after therapy did not exclude the presence of underlying intestinal metaplasia.

Relationship between the severity of retinopathy and progression to photocoagulation in patients with Type 2 diabetes mellitus in the UKPDS (UKPDS 52).

AIM: to establish the degree to which the severity of retinopathy determines the risk for the need for subsequent photocoagulation in those with newly diagnosed Type 2 diabetes mellitus. METHODS: Of 5102 patients entered into the UK Prospective Diabetes Study (UKPDS), 3709 had good quality retinal photographs that could be graded at entry. They were followed until the end of the study or until lost to follow-up, or until they received photocoagulation. Retinopathy severity was categorized as no retinopathy, microaneurysms (MA) only in one eye, MA in both eyes or more severe retinopathy features. The risk of photocoagulation was assessed in relation to severity of retinopathy at baseline, 3 and 6 years. RESULTS: Of the 3709 patients assessed at entry to the UKPDS, 2316 had no retinopathy. Of these 0.2% needed photocoagulation at 3 years, 1.1% at 6 years and 2.6% at 9 years. Those with MA in one eye only (n = 708) were similar, with 0%, 1.9% and 4.7% needing photocoagulation by 3, 6 and 9 years, respectively. Amongst those who had more retinopathy features at entry (n = 509), 15.3% required photocoagulation by 3 years, and 31.9% by 9 years. When those without retinopathy at 6 years (n = 1579) were examined 3 and 6 years later (9 and 12 years after diagnosis), 0.1% and 1.8% required photocoagulation. Those with more severe retinopathy (n = 775) needed earlier treatment, 6.6% after 3 years and 13.3% after 9 years. The commonest indication for laser therapy was maculopathy, but those with more severe retinopathy were more likely to be treated for proliferative retinopathy and to need both eyes treated. CONCLUSION: Few type 2 diabetic patients without retinopathy progress to photocoagulation in the following 3-6 years, while patients with more severe retinopathy lesions need to be monitored closely.

Fundamentos del láser y su aplicación en la urología / The basics of laser and its application in urology

El láser, dispositivo de amplificación de luz por emisión estimulada de radiación, se trata de un dispositivo capaz de transformar otras energías en radiación electromagnética emitiendo haces de luz de distintas longitudes de onda. Se trata de aparatos que amplifican la luz y producen haces de luz coherentes cuya frecuencia va desde el infrarrojo hasta los rayos X. La emisión estimulada, proceso en que se basa el Láser, fue descrita por A. Einstein en 1917, pero no es hasta la década de los 60, cuando se observó el primer proceso láser en un cristal de rubí. Según el medio que emplean, los láseres suelen denominarse de estado sólido, de gas, semiconductores o líquidos. Los posibles usos del láser son casi ilimitados, convirtiéndose en una herramienta muy valiosa dentro de las Ciencias biomedicas, gracias a los diversos efectos (fotovaporización, fotodisrupción, fotocoagulación o fotoestimulación) que provoca al interactuar con los tejidos. Por este motivo, hoy día, el uso de láseres en el campo de la Urología nos ofrece un amplio abanico de posibilidades, que van desde la cirugía desobstructiva como la fragmentación de un cálculo o la resección y ablación del tejido prostático hasta la cirugía reconstructiva como es la soldadura de tejidos en la vasovasostomía o la reparación de una estenosis uretral (AU)

A laser, light amplification by stimulated emission of radiation, is a device able to transform other energies into electromagnetic radiation with emission of light beams of different wavelengths. They amplify the light and produce coherent light beams, the frequency of which varies from infrared to X ray. Stimulated emission, the process laser is based on, was described by A. Einstein in 1917, but it was not until the decade of the '60s when the first laser process was observed in a ruby crystal. Depending on the environment they use, lasers may be named as solid-state, gas, semiconductors or liquid. The possibility of uses for laser is almost unlimited, becoming a very valuable tool in biomedical sciences thanks to the various effects they produce when interacting with tissues (photovaporization, photodisruption, photocoagulation or photostimulation). For this reason, today, the use of lasers in the field of urology offers a wide range of possibilities, going from surgery for the treatment of obstruction, such as the fragmentation of a urinary stone or resection/ablation of prostatic tissue, to reconstructive surgery, such as tissue welding in vasovasostomy or urethral stenosis repair (AU)

Clinical applications of the 810 nm diode laser in the Caribbean [abstract]

The 810 nm diode laser has many properties and applications that make it particularly suitable for use in opthalmic laser/surgical centres in the Caribbean. Microplus, subthreshold pan-retinal photocoagulation allows laser treatment for proliferative diabetic retinopathy and Central Retinal Vein Occlusion (CRVO) to be completed in a single treatment session. This is essential for patients who travel a great distance for treatment, or in whom compliance is an issue. Laser-induced chorio-retinal shunt is a possible treatment for CRVO. Trans-scleral diopexy is more effective than cryotherapy for treating peripheral retinal tears, and does not require the expense and maintenance necessitated by the use of gas cylinders. Age-related macular degeneration (ARMD) is much more common in the Caribbean than previously thought. Transpupillary thermotherapy for exudative ARMD and prophylactic grid treatment for dry ARMD are effective treatments that do not require expensive drugs and their associated side effects. Diode laser trans-scleral cyclophotocoagulation is an effective out-patient, non-surgical procedure for controlling glaucoma in patients who have failed medical management or for whom cost or a compliance issue makes medical management impractical. The size and portability of the diode laser is ideal for use and travel between different offices and surgical suites. (AU)

La fotocoagulación infrarroja para el tratamiento de las hemorroides / Infrared photocoagulation for the treatment of the hemorroids

Se analizaron 171 pacientes con hemorroides sintomáticas, 129 de 1er y 2do grado y 42 de 3er grado, tratadas con fotocoagulación infrarroja (F.I.). Un 94.5%de 129 enfermos seguidos 6 meses, sobre 149 con esa evolución, se hallaban sin síntomas o muy aliviados. Esta proporción de buenos resultados se mantuvo en los 91 casos seguidos 1 año, sobre 112 posibles. Entre estos últimos, hubo 98%de buenos resultados en las hemorroides de 1er y 2do grado y 86%en las de 3er grado. Un 12.8%de la serie presentó dolor, proctorragia o trombosis hemorroidaria luego de alguna sesión del tratamiento, destacándose en varios casos la relación del dolor con la reapertura de una fisura anal recientemente cicatrizada y 1 proctorragia severa al 10 día de una fotocoagulación. Estos efectos desfavorables pueden disminuirse si no se efectúan más de 6 disparos del rojo infrarrojo en una misma hemorroide, ni más de 8 en total en 2 ó más hemorroides. La fotocoagulación infarroja es un método sencillo y rápido, no interrumpe las actividades habituales del paciente, produce pocos efectos colaterales, resultados muy efectivos en hemorroides de 1er y 2do grado y satisfactorios en hemorroides de 3er grado. Estos se logran cuando el tratamiento se prolonga hasta la desaparición o disminución satisfactoria de los síntomas

El manejo ambulatorio de la hemorroide interna con fotocoagulación infrarroja / The outpatient management of internal hemorrhoids by infrared photocoagulation

Infrared photocoagulation is a new ambulatory therapy for 1st, 2nd and 3rd degree internal hemorrhoids. It is an effective method, comparable to others such as sclerotherapy or rubber band ligature. It is necessary to use multiple applications in several sessions in order to obtain good results. Patients with hemorrhoids grade IV are candidates for hemorrhoidectomy. The author did not observe minor nor serious complications with this new therapeutic modality. It is fast and easy to use by a single operator. The equipment is portable, easy to handle and long lasting, needing little maintenance. The anatomical results suggest that the progression of hemorrhoids and also, probably, surgery are prevented. Long-term follow up is necessary

Xenon photocoagulation - an alternative to laser therapy in diabetic retinopathy

Diabetic retinopathy is a frequent cause of blindness. The treatment of choice is photo-coagulation for both diabetic maculopathy and proliferative retinopathy. Effective photo-coagulation can be with the Xenon Arc photo-coagulator. this is much cheaper than an Argon laser. It requires no maintenance. In areas in which laser s unavailable the Xenon Arc photo-coagulator is a safe and practical form of treatment. (Summary)