Panretinal photocoagulation (PRP) and macular photocoagulation (MPC) are the gold standard treatments for proliferative diabetic retinopathy (DR) and diabetic macular edema. With the development of equipment and technology advancement, photocoagulation has been gradually applied in many Eye Centers all over China. However, there are still several problems such as no standardized guideline and undesirable therapeutic effects. In this article we will summarize the indications and techniques of photocoagulation, and when and how to apply drug treatments for retinal diseases; aim at improving the criterion and clinical effects of photocoagulation.
ObjectiveTo investigate the efficacy of laser photocoagulation and intravitreal ranibizumab treatment of retinopathy of premature(ROP).
MethodsThis study included 49 ROP infants (96 eyes), including type 1 pre-threshold ROP (7 infants, 14 eyes), threshold ROP (38 infants, 44 eyes) and aggressive posterior ROP (AP-ROP, 4 infants, 8 eyes). According to the treatments received, all patients were divided into laser photocoagulation (LP) group (40 infants, 78 eyes) and intravitreal ranibizumab (IVR) treatment group (9 infants, 18 eyes). Generally, zoneⅡand stage 3 ROP with clear refractive media received laser photocoagulation, zoneⅠROP and AP-ROP, or eyes with unclear refractive media or infants with poor general condition received IVR. The infant gestational age, birth weight, corrected gestational age at first treatment and the cure rate of the first treatment were analyzed between the two groups, and between three disease types (type 1 pre-threshold, threshold and AP-ROP).
ResultsThe gestational age and birth weight was no difference between the LP group and IVR group (t=0.827, 1.911; P > 0.05). The corrected gestational age at first treatment of LP group was significantly smaller than that in the IVR group (t=3.041, P < 0.05). In the LP group, 75 of 78 eyes (96.15%) was cured by the first treatment, 3 of 78 eyes (3.85%) progressed to stage 4A after the first treatment and was controlled by vitrectomy. In the IVR group, 8 of 18 eyes (44.44%) was cured by the first treatment, 10 of 18 eyes (55.56%) progressed to next stage after the first treatment and was controlled by additional laser photocoagulation or repeated IVR. The gestational age and birth weight was no difference between type 1 pre-threshold, threshold and AP-ROP infants (t=2.071, 0.664; P > 0.05). The corrected gestational age at first treatment of type 1 pre-threshold infants was the same of the threshold lesion infants (t=2.054, P > 0.05). The corrected gestational age at first treatment of AP-ROP infants was significantly smaller than that of type 1 pre-threshold and threshold lesion infants (t=3.250, P < 0.05). The cure rate was statistically significant (χ2=24.787, P < 0.05) between there three ROP lesions.
ConclusionIVR treatment is suitable for zoneⅠlesions, AP-ROP and Plus lesions, while laser photocoagulation is appropriate for zoneⅡlesions with fibrosis and less vascular proliferation.
Objective
To determine the efficacy of D980-nm laser in dissolving fat and renewing skin, and to explore the clinical application of D980-nm laser in reconstruction of photodamaged skin.
Methods
Eighteen 12-14 month-old male Sprague-Dawley rats, weighing 400-450 g, were randomly divided into 3 groups (n=6). The rat skin at the left side was exposed to D980-nm laser irradiation at a density of 20 J/cm2, a power of 8 W, a pulse width of 20 ms, and a pulse frequency of 40 Hz for 1 time (group A), 2 times of 5-minute interval (group B), and 3 times of 5-minute interval (group C) as a treatment course, for 4 treatment courses with an interval of 1 week; the other side of the skin was not treated as the control groups (groups A1, B1, and C1, respectively). After 8 weeks, the skin was harvested for HE staining and immunohistochemical staining to observe the structure changes of skin, to measure the dermal thickness, to count the number of fibroblasts, and detect the expressions of transforming growth factor β1 (TGF-β1) and basic fibroblast growth factor (bFGF).
Results
Compared with groups A1, B1, and C1, the skin structure was significantly improved in groups A, B, and C. After D980-nm laser irradiation, the number of fat cells decreased; local angiogenesis was observed; the total number of fibroblasts and fibers increased; the collagen fiber had large diameter, and arranged closely and regularly; the dermal thickness and the number of the fibroblasts increased; and the expressions of TGF-β1 and bFGF were significantly enhanced, showing significant differences (P<0.05). With increased D980-nm laser irradiation times, the above indexes increased, showing significant differences between group C and groups A, B (P<0.05).
Conclusion
D980-nm laser treatment has lipolytic and tender effect on the skin, and the frequency of the treatment is an important factor in skin renewal.
ObjectiveTo observe the efficacy of pars plana vitrectomy (PPV) combined with endoscopic cyclophotocoagulation (ECP) for refractory glaucoma.
MethodsTwenty-eight patients (30 eyes) diagnosed with refractory glaucoma were enrolled in this study. The intraocular pressure was ranged from 28 to 55 mmHg (1 mmHg=0.133 kPa), with the mean of (46.3±10.3) mmHg. There were 24 eyes with initial visual acuity <0.05, 1 eye with 0.05-0.08 initial visual acuity and 5 eyes with ≥0.1 initial visual acuity. The mean number of intraocular pressure-decreased drugs was 4. All the eyes underwent PPV combined with ECP. The cyclophotocoagulation ranged from 90°-360°, with the mean of (232.5±77.6)°. The cyclophotocoagulation was <180° in 4 eyes, 180°-270° in 6 eyes, >270° in 20 eyes. The follow-up ranged from 12 to 20 months, with the mean of 15.2 months. The intraocular pressure, vision and the mean number of intraocular pressure-decreased drugs before and after surgery were comparatively observed. The relationship between cyclophotocoagulation area and postoperative intraocular pressure was analyzed.
ResultsAt the final follow-up, the intraocular pressure ranged from 12 to 36 mmHg, with the mean of (18.5±4.4) mmHg, which decreased 49.4% compared with preoperative intraocular pressure (t=15.537, P<0.01). Among 30 eyes, the intraocular pressure was ≤21 mmHg without any intraocular pressure-decreased drugs in 24 eyes (80.0%), 1 eye (3.3%) with ≤21 mmHg who treatment by local intraocular pressure-decreased drugs, lose control of intraocular pressure in 5 eyes (16.7%). The vision was <0.05 in 15 eyes, 0.05-0.08 in 3 eyes and ≥0.1 in 12 eyes. The difference of vision distribution before and after surgery was not significant (χ2=6.197, P>0.05). Compared with preoperative vision, the postoperative vision was improved in 8 eyes (26.7%), stabled in 15 eyes (50.0%), decreased in 7 eyes (23.3%). The mean number of intraocular pressure-decreased drugs was reduced from 4 to 1 (t=8.402, P<0.01).The cyclophotocoagulation area was positive related to postoperative intraocular pressure (r=4.160, P<0.05). There were no ocular and systemic complications during and after surgery except slight inflammation.
ConclusionPPV combined with ECP for refractory glaucoma can reduce intraocular pressure, stabilize or improve the visual acuity.
ObjectiveTo evaluate the outcomes of laser photocoagulation of congenital X-linked retinoschisis (XLRS) at progressive stage.
MethodsTwenty-seven cases (36 eyes) of XLRS sick kids were enrolled in this study. All patients were followed up for more than 1 year, retinoschisis has developed slowly but complications occurred during the follow-up. They are all boys from 3 to 12 years old; the average age was 6.47 years old. There were 18 unilateral cases, 9 bilateral cases. The affected eyes were randomly divided into treatment group and control group (n=18 eyes). The treatment group eyes received multi-wavelength krypton yellow laser photocoagulation around the retinoschisis, but no laser spots were laid in a optic-disk area surrounding the macular and optic disc. Children in the control group were followed up every six months without treatment. Both groups of children were followed up for 3 years. The best corrected visual acuity (BCVA, logMAR), complications (vitreous hemorrhage, retinal detachment) were measured at the last follow up.
ResultsAt the last follow-up, the treatment group mean logMAR BCVA was 0.73±0.41, which is the same as pre-treatment BCVA (t=1.187, P=0.201). The control group mean logMAR BCVA 0.88 ±0.60, which is the same as pre-treatment BCVA (t=-2.093, P=0.033). The changes of the BCVA in these two groups was statistically different (t=-2.093, P=0.033). For the treated 18 eyes, visual acuity improved in four eyes (22.2%); not changed in 10 eyes (55.6%) and decreased in four eyes (22.2%). For the 18 eyes in the control group, visual acuity improved in three eyes (16.7%); not changed in four eyes (22.2%) and decreased in 11 eyes (61.1%). The vision reduction rate in treatment group was statistically less than the control group (χ2=5.600, P<0.01). There were 2 eyes (11.1%) and 7 eyes (38.9%) with serious complications in the treated and control eyes respectively. The complication rate treatment group was statistically less than the control group (χ2=3.710,P<0.05).
ConclusionLaser photocoagulation can stabilize or improve vision of advanced XLRS patients, and prevent the occurrence of serious complications.
ObjectiveTo observe the change of retinal microstructures and the association between visual outcome with these microstructures in central serous chorioretinopathy (CSC) after laser treatment.MethodsThis is a retrospective study. From April 2016 to February 2017, a total of 52 eyes from 52 patients who underwent conventional laser treatment (27 eyes) or subthreshold laser treatment (25 eyes) for CSC and the sub-retinal fluid (SRF) absorbed completely were included in this study. The were 46 patients (46 eyes) and 6 males (6 eyes), with the mean age of 43.92±8.62 years. The healthy fellow eyes (49 eyes) were selected as control. All patients were underwent BCVA and SD-OCT examination. According to the OCT images for all patients, the thickness of central foveal (CFT), outer nuclear (ONL), inner segment (IS), outer segment (OS) were measured. The status of ellipsoid zone (EZ), interdigitation zone (IZ) and RPE were also evaluated at fovea. Comparing the change of SD-OCT microstructures in two time points, the first visit after SRF absorbed and the last visit respectively. Spearman correlation analysis was used to analyze the relation between BCVA and ONL, IS, OS.ResultsAt the first visit after SRF absorbed, compared with control eyes, the thickness of CFT (182.55±24.14 μm), ONL (72.86±17.39 μm), IS (41.23±5.14 μm), OS (18.52±10.26 μm) in CSC eyes were decreased (P＜0.001). Meanwhile, the mean BCVA of CSC eyes was 81.27±6.39 letters, which was also significantly decreased comparing with control eyes (P＜0.001). At last visit, the thickness of CFT, ONL, IS, OS were 195.19±22.10, 75.44±16.33, 44.56±4.09, 26.60±11.39 μm, and the mean BCVA was 85.50±5.95 letters. All recovered significantly comparing with first visit (P＜0.05). At first visit, the BCVA of patients with integrate EZ (83.38±5.78 letters) was significantly better than the BCVA of patients with unintegrated EZ (77.90±5.97 letters) (P=0.003). And the BCVA of patients with smooth RPE (82.72±5.95 letter) was also significantly better than the BCVA of patients with rough RPE (78.00±6.31 letters) (P=0.020). The result of Spearman correlation analysis showed that the thickness of OS was positively correlated to BCVA at two time points (r=0.423, 0.416; P=0.002, 0.002).ConclusionsIn CSC, the thickness of ONL, IS, OS were decreased, and the integrality of EZ, IZ, the smooth of RPE were disrupted in different extent. After laser treatment, with retinal reattachment, those microstructures including ONL, IS, OS, EZ, IZ recovered slowly. The thickness of OS, the integrality of EZ and the smooth of RPE were associated with visual acuity.
Ultra-rapid cooling and rewarming rate is a critical technical approach to achieve ice-free cells during the freezing and melting process. A set of ultra-rapid solid surface freeze-thaw visualization system was developed based on a sapphire flim, and experiments on droplet freeze-thaw were carried out under different cryoprotectant components, volumes and laser energies. The results showed that the cooling rate of 1 μL mixed cryoprotectant [1.5 mol/L propylene glycol (PG) + 1.5 mol/L ethylene glycol (EG) + 0.5 mol/L trehalose (TRE)] could be 9.2×103 °C/min. The volume range of 1–8 μL droplets could be vitrified. After comparing the proportions of multiple cryoprotectants, the combination of equal proportion mixed permeability protectant and trehalose had the best vitrification freezing effect and more uniform crystallization characteristics. During the rewarming operation, the heating curve of glassy droplets containing gold nanoparticles was measured for the first time under the action of 400–1 200 W laser power, and the rewarming rate was up to the order of 106 °C/min. According to the droplet images of different power rewarming processes, the laser power range for ice-free rewarming with micron-level resolution was clarified to be 1 400–1 600 W. The work of this paper simultaneously realizes the ultra-high-speed temperature ramp-up, transient visual observation and temperature measurement of droplets, providing technical means for judging the ice free droplets during the freeze-thaw process. It is conducive to promoting the development of ultra-rapid freeze-thaw technology for biological cells and tissues.
ObjectiveTo observe the outcome of posterior staphyloma (PS) marginal retinal photocoagulation in pars plana vitrectomy (PPV) for high myopia macular hole retinal detachment eyes accompanied with PS.MethodsFrom January 2017 to June 2019, 49 patients (49 eyes) with high myopia macular hole retinal detachment accompanied with PS who were undergone PPV operation from Tianjin Eye Hospital were included in this study. There were 13 males (13 eyes) and 36 females (36 eyes). All patients underwent best corrected visual acuities (BCVA) and optical coherence tomography examinations. The standard logarithmic visual acuity chart was used for BCVA examination, and the visual acuity was converted to minimum resolution angle in logarithmic (logMAR) when recorded. The patients were randomly divided into two groups according to surgical options: conventional PPV with internal limiting membrane (ILM) peeling (group A, 24 eyes), PS marginal retinal photocoagulation in PPV with ILM peeling (group A, 25 eyes). The mean preoperative logMAR BCVA of group A and B were 1.87±0.28 and 1.80±0.37, the difference was not statistically significant (t=0.604, P=0.551). The patients in the group A received 23G PPV, triamcinolone acetonide staining during the operation, the epiretinal membrane was peeled off, indocyanine green assisted staining, the posterior macular ILM was peeled off, and the peripheral retina was examined in detail during the operation. Areas with retinal degeneration were reinforced by laser photocoagulation, and the subretinal fluid was drained through the macular hole and filled with silicone oil. The eyes of the group B were subjected to retinal photocoagulation for 2 to 3 rows at the edge of the PS in addition to the usual surgical procedures. The average follow-up time was 8.34±3.21 months. Surgical outcome were estimated by the average number of operation, retinal reattachment rate, macular hole closure rate and BCVA. The χ2 test or Fisher exact probability was used to compare the count data. Independent sample t test was used to compare the measurement data.ResultsRetinal reattachment was obtained in 17 eyes (70.8%, 17/24) and 24 eyes (96.0%, 24/25) in group A and B after first surgery respectively, the difference was statistically significant (χ2=3.984, P=0.046). Final retinal reattachment was obtained in all 49 eyes. Final macular hole closure was in 15 eyes (62.5%, 15/24) and 19 eyes (76.0%, 19/25) in group A and B, respectively, the difference was not statistically significant (χ2=1.051, P=0.305). The mean postoperative logMAR BCVA of group A (1.20±0.47) and B (1.08±0.39) were all improved than preoperative BCVA, the differences were all statistically significant (t=2.899, 5.327; P=0.001, 0.000), the differences of mean postoperative logMAR BCVA between two groups was not statistically significant (t=0.675, P=0.506). The mean number of operation of group A (2.63±0.88) was more than group B (2.08±0.28), the difference was statistically significant (t=3.003, P=0.006).ConclusionIn comparison with conventional PPV, combined PS marginal retinal photocoagulation can improve retinal reattachment rate after first surgery, and reduce the number of reoperations.
Objective
To observe the morphologic alterations of retina pigment epithelial around fluorescein leakage site using spectral-domain optical coherence tomography (SD-OCT) in acute central serous chorioretinopathy (CSC) before and after laser coagulation.
Methods
Twenty-four eyes of 24 consecutive patients with unilateral acute CSC who underwent laser photocoagulation (wave length: 561 nm, energy: 80-100 mW, spot diamteter: 100 μm, exposure time: 0.1 s) were enrolled in this retrospective study. The patients included 22 males and 2 females, with an average age of (39.2±7.2) years and an average duration of (1.1±0.6) months. The fluorescein leakage outside the foveal avascular zone and serous retinal detachment were found in all the eyes by fluorescein fundus angiography (FFA) and SD-OCT. Twenty-six leakage sites were observed in 24 eyes on FFA. There were 5 smoky leakage points (19.2%), 21 inky leakage points (80.8%). The retinal pigment epithelial (RPE) layer at leakage points were scanned by SD-OCT before and at 2 weeks, 2 months after treatment. SD-OCT showed that the RPE abnormalities were detected at all of the fluorescein leakage points, including serous pigment epithelial detachment (PED) in 16 leakage points (64.5%), protruding RPE in 5 leakage points (19.5%), and irregular RPE in 5 leakage points (19.2%). The morphologic alterations of RPE around fluorescein leakage point before and after laser coagulation were observed.
Results
At 2 weeks after laser photocoagulation, PED existed in 7 leakage points (26.9%), protruding RPE in 3 leakage points (11.5%), and irregular RPE in 16 leakage points (61.5%). At 2 months after laser photocoagulation, protruding RPE existed in 3 leakage points (11.5%), and irregular RPE in 5 leakage points (19.2%), including RPE defect in 2 leakage points. And there were undetectable RPE abnormalities in other 16 leakage points (61.5%).
Conclusions
In acute CSC, SD-OCT shows that morphologic features of the RPE layer are changed, including PED, protruding RPE, irregular RPE around the leakage point. After laser photocoagulation the abnormalities of RPE can also be altered from PED to irregular RPE, and RPE defect is observed in restricted regions.
