Volume 50 · Issue 05 · 2014

It is very important for us to establish the technological specifications in medical field.Many problems will appear if we neglect them , which include difficulty in approving the results of examination with each other , waste of medical resources and increase of patients′time and expense , lack of guarantee for medical quality and safety and insupportable for further study with collecting medical data , etc.Although many technical operations were included in glaucoma field , unified technical specification was still deficiency in our country , which will have some certain influence on the clinical and research work.Only increasing the understanding of importance of technological specifications and establishing the applications of glaucoma′s technical specifications , our whole level of glaucoma diagnosis and treatment will be raised in the whole country.

Early diagnosis of primary open-angle glaucoma has not been clear and consistent in concepts and methods.At present, according to the pathophysiology process of optic nerve damage and its detection technology , early diagnosis on the concept still belongs to the early clinical diagnosis instead of preclinical diagnosis , and on the method depends on the fundus as morphological index combined with the visual field as functional index.The direction of early clinical diagnosis mainly lies in exploring more effective diagnosis index , rather than blindly adopt new diagnostic technology.

The new criteria to classify and diagnose primary angle-closure glaucoma ( PACG ) proposed by International Society Geographical&Epidemiological Ophthalmology ( ISGEO) brought about not only new concept but also huge impact on Chinese traditional classification established in 1987.The controversy between these two systems has baffled Chinese ophthalmologists in years of clinical practice .The new criteria obviously has some concepts not suitable and not practical for Chinese PACG patients .However , domestic studies based on traditional classification are not internationally valued or accepted .Chinese own evidence-based clinical trials are urgently needed to elucidate the pros and cons of two classification systems.

Myopia, especially high myopia, is a risk factor for glaucoma independent of intraocular pressure. This conclusion, which has been noted in both domestic and foreign textbooks, has recently been confirmed by a large sample population study. Epidemiological investigations and clinical studies based on different ethnic groups in different regions have shown that patients with myopia, especially high myopia, have an increased risk of developing glaucoma. In the Australian Basket Mountain Eye Disease Study, the prevalence of glaucoma in low-grade myopia, moderate-high myopia and non-myopia were 4.2%, 4.4% and 1.5%, respectively. The rate of glaucoma in myopia was significantly higher than that in non-myopia, and this significance still exists after adjusting for glaucoma risk factors such as family history of glaucoma [1]. The prevalence of glaucoma was significantly higher in the high myopia group (7.1%) than in the moderate myopia group (2.3%), low myopia group (2.4%), emmetropia group (0.8%), and hyperopia group (1.8%) [2]. The Los Angeles Latin American Eye Disease Study also showed that after correcting for intraocular pressure, people with moderate to high myopia were significantly more likely to develop glaucoma than those with low myopia and emmetropia, and the chance of developing glaucoma increased by 26% for every 1 mm of axial length [3]. A meta-analysis conducted by Marcus et al. [4], which included 48,161 people in 31 studies, showed that both low myopia and moderate to high myopia were glaucoma risk factors, with OR values of 1.65 and 2.46, respectively.

Myopia and glaucoma have been a hot topic in the clinical and basic research fields of glaucoma. Because of myopia caused by the tilt of the optic head, torsion, peridisc atrophic arc, leopard-shaped fundus, it is difficult to judge the optic nerve damage in POAG. At the same time, because some clinical or epidemiological studies from the population have shown that the intraocular pressure of myopic patients is higher than that of non-myopic patients, the risk of glaucoma in myopic patients increases, and the progression rate of glaucoma optic nerve damage in myopic patients increases. Most scholars believe that myopia is a risk factor for glaucoma [1].

The research team of "Beijing iCOP Research" led by Professor Wang Ningli of Beijing Tongren Ophthalmology Center of Beijing Tongren Hospital affiliated to Capital Medical University has changed people's understanding of glaucoma by studying the effect of pressure gradient across sieve plates. Last year, the Glaucoma Group of Ophthalmology Branch of Chinese Medical Association selected the top ten research progress of glaucoma in China in the past five years, and iCOP research ranked first. With the publication of this research series of articles, glaucoma colleagues at home and abroad have paid great attention to it. At the beginning of this year, Professor Christophe Baudouin, president of the French Ophthalmology Society and glaucoma expert, spoke highly of the contribution of Beijing iCOP research and affirmed its value to improving the theory of glaucoma diagnosis and treatment.

Objective To measure the intraocular pressure ( IOP) in different sleep positions and compare with IOP in the sitting position.Methods Perspective study.Thirty-two patients with primary open angle glaucoma ( POAG) and 28 normal subjects had IOP measured in the sitting position and then again in the supine , right lateral decubitus ( right-lateral ) and left lateral decubitus ( left-lateral ) positions with a Perkins applanation tonometer.IOPs then were measured again in the sitting postion after 1, 5 and 10 minutes.Two-way ANOVA was used to compare IOP readings in the different positions among the two study groups.Data were shown as mean ±standard deviation.Results In normal subjects , the IOP values of the right eye were (17.5 ±3.8) (sitting), (19.3 ±3.1) (supine), (21.7 ±3.7) (right-lateral) and (21.5 ±3.7) mmHg (left lateral) (1 mmHg=0.133 kPa).The IOP values of left eye were (18.4 ±3.0) (sitting), (19.3 ±3.1) (supine), (20.7 ±2.9) (right-lateral) and (22.8 ±4.0) mmHg (left lateral).In the POAG patients , the IOP values of the right eye were ( 17.9 ±3.7 ) ( sitting ) , ( 20.6 ±4.6 ) (supine), (26.1 ±7.1)(right-lateral) and (26.3 ±5.9) mmHg (left-lateral).The IOP of the left eye in these positions were ( 18.2 ±3.6 ) , ( 20.0 ±4.1 ) , ( 25.6 ±6.1 ) and ( 25.7 ±6.0 ) mmHg, respectively.The IOP under the right-and left-lateral positions were higher than that in sitting and supine in both groups.The IOP increases in all positions for POAG patients were significant higher than in normal subjects.The IOP decreased rapidly after returning from the supine to the sitting position.The IOP values at 1 minute, 5 minutes and 10 minutes after returning to the sitting position were not significantly different than the original sitting.Conclusions The IOP in lateral decubitus positions is significantly higher than the IOP in sitting and supine positions.These differences are greater in POAG.

Objective To compare the safety and efficacy between canaloplasty and aqueous drainage pathway reconstruction surgery in patients with open-angle glaucoma ( OAG).Methods It is a retrospective case series study.Thirty-one eyes (25 patients) with OAG were divided into canaloplasty (n=17;54.8%) group or aqueous drainage pathway reconstruction ( n=14;45.2%) group.The intraocular pressure ( IOP ) , numbers of IOP-lowering medications and incidence of complications were recorded at 1 day, 1 week, 1, 3, 6 and 12 months after the operation.Independent-samples T test was used to compare the IOP, numbers of IOP-lowering medications before and 1, 3, 6, 12, 24 months after surgery between two groups.Kaplan-Meier Survival Analysis was used to analyze the success rate of these two surgical methods.Log rank test was used to compare the difference of cumulative success rate at 6, 12 months after surgery.Results The mean IOP values were (24.7 ±8.7), (14.5 ±2.5), (14.9 ±2.5), (14.9 ±2.5), (14.7 ±2.1) and (15.4 ±2.3)mmHg (1 mmHg=0.133 kPa) in canaloplasty group at before surgery , 1, 3, 6, 12 and 24 months after surgery.The same values were (28.5 ±10.6), (14.3 ±3.6), (14.2 ±3.2), (14.3 ± 3.6), (15.9 ±3.2) and (14.6 ±0.7)mmHg in aqueous drainage pathway reconstruction group.There was no difference in the extent of IOP reduction between these two groups ( preoperative: t =-1.1014, P=0.278;postoperative 1 month:t=0.696,P=0.492;3 month:t=0.594,P=0.557;6 month:t=0.536, P=0.596;12 month:t=-1.127, P=0.273;24 month:t=0.455, P=0.656).There were significant differences ( P<0.01) in post-surgery IOP lowering medication usage between these two groups , while pre-surgery medication usage were similar.The incidence of hyphema was significantly lower in aqueous drainage pathway reconstruction surgery group ( 2 eyes ) than that in canaloplasty group ( 11 eyes ).Conclusions Both canaloplasty and aqueous drainage pathway reconstruction could reduce IOP effectively for open -angle glaucoma.The incidence of complication was lower in the aqueous drainage pathway reconstruction group than canaloplasty group.However, long-term efficacy between these two groups is yet to be determined.

Objective To compare the efficacy of selective laser trabeculoplasty ( SLT ) versus prostaglandinanalogue ( PGA) in the treatment of open angle glaucoma ( OAG) and ocular hypertension ( OHT) . Methods Literature analysis.Systematic review of randomized controlled trials comparing SLT versus PGA , identified by searching literatures including Medline (January,1966-December, 2012), EMBASE Reviews ( January , 1974-December , 2012 ) OVID Evidence-Based Medicine Reviews ( January , 1966-December , 2012), Chinese BioMedical Literature Database SinoMed (January,1966-December, 2012), and CNKI (January,1999-December, 2012).RevMan 5.0 was used to do meta-analysis.Results Three publications reporting 3 trials, 161 participants ( 231 eyes ) with OHT or OAG were included for meta-analysis.IOP reduction favored PGA group,weighted mean difference (WMD) =-0.85 [1 mmHg=0.133 kPa;95%confidence interval (CI) ( -1.43 to -0.27), no significant heterogeneity present ( P =0.82, I2 =0%)].Success rates are equal in two groups [OR =0.70,95%CI =(0.49 to 1.19), no significant heterogeneity present (P=0.58,I2 =0%)].Eyes underwent additional antiglaumatous interventions favored SLT group,OR=1.11 [95%CI =(0.60 to 2.06), significant heterogeneity present, (P=0.08, I2 =61%) ].Conclusions As primary therapy of OAG or OHT , SLT is no more effective than PGA in success rate.IOP reduction affected by SLT is not effective than PGA.Compared with PGA , SLT can reduce the use of anti-glaucoma medications.

The first ocular biometry study class sponsored by Tianjin Medical University Eye Hospital will be held in Tianjin from July 12 to 13, 2014. The study class is taught by Professor Zhang Hong, a well-known cataract expert in China, Professor Yang Wenli, an ophthalmic ultrasound expert, and Colin Song, director of ophthalmic biometry in our hospital. The study covers the principles of Mode A ultrasound, optical biometry and corneal curvature, instrument use, standard operating procedures and measurement error analysis; Biometric measurement of special eyes such as extra-long axis, silicone oil eye and post-corneal refractive surgery; Selection of calculation formula for intraocular lens, selection of target diopter after surgery. Teaching methods include lectures and field operations of various biometric devices.