Effects of Photobiomodulation Therapy on Patients with Primary Open Angle Glaucoma: A Pilot Study.
11 Otto-Meyerhof Center, University of Heidelberg , Heidelberg, Germany .
22 Medical Center , Munich, Germany .
The purpose of this work was to study the safety of photobiomodulation therapy in patients with primary open angle glaucoma (POAG).
Therapeutic options for POAG focus on lowering the intraocular pressure (IOP) but cannot stop disease progression to irreversible damages.
The study was designed as a controlled, single-blinded, interventional case series (38 patients; 63 eyes). Low-level laser therapy was performed once or twice per week using a continuous wave (CW) diode laser (780 nm; 10 mW; 292 Hz modulation; 3 mm2 beam spot). The limbus area was circularly irradiated for 30 sec (0.3W/cm2; 10J/cm2) at a 1 cm distance. Additional parts of the bulbus were irradiated for 90 sec (30 J/cm2) pointing the beam toward retinal areas corresponding to defective visual fields. A control group of 10 patients (20 eyes) received mock treatment. Visual acuity was assessed using Snellen projection optotypes. IOP was determined by applanation tonometry. Visual fields were determined by kinetic Goldmann perimetry. Multifocal visual evoked potential (M-VEP) was recorded in 15 patients (30 eyes).
Poor visual acuity (20/25), initially found in 24 of 63 eyes (38.1%), improved in 17 (70.8%) eyes and did not change in 7 eyes (29.2%). Mean IOP dropped from 24.9 ± 14.9 to 15.0 ± 6.5 mm Hg (-39.7%, p<0.001). Visual fields were either fully restored, improved by at least 10 degrees, or remained unchanged in 32, 29, and 2 of 63 eyes (51%, 46%, and 3%), respectively. Mean M-VEP latency was reduced by 13.5 msec (-8%, p<0.001); mean amplitude increased by +677 nV (+14%, p<0.001). Adverse effects were not observed. No changes were noted in control eyes.
This first small series of cases indicated that photobiomodulation might be a safe approach to lower IOP and to improve visual acuity and fields in eyes with POAG.
Optimal selective laser trabeculoplasty energy for maximal intraocular pressure reduction in open-angleglaucoma.
- 1*The Department of Ophthalmology, Caritas Medical Centre †The Department of Ophthalmology, The University of Hong Kong ‡The Department of Ophthalmology, Queen Mary Hospital §Department of Applied Mathematics, The Hong Kong Polytechnic University, Hong Kong, SAR, People’s Republic of China.
To identify the optimal energy level to be used in selective laser trabeculoplasty (SLT) for maximal intraocular pressure (IOP) reduction in open-angle glaucoma (OAG) patients.
PATIENTS AND METHODS:
This cohort sequentially recruited OAG subjects in Hong Kong, China during 2011 to 2012. All subjects received a single session of SLT with near confluent spots to 360 degrees of the trabecular meshwork. An initial energy of 0.8 mJ was titrated until bubble formation was just visible. The main outcomes included: change in IOP (pre-SLT to 1 mo post-SLT) and total SLT energy (SLT spots multiplied by the mean energy). For statistical analysis, only the right eye of each subject was used. Bandwidth selection by generalized cross-validation was used to determine the optimal interval and point of total SLT energy that resulted in the largest IOP reduction.
A total of 49 Chinese OAG subjects had a mean age of 64.2±11.1 years. The pre-SLT IOP was 17.1±2.9 mm Hg while on 1.9±1.1 types of antiglaucoma eye drops. The mean total energy was 167.1±41.4 mJ (171.5±41.2 spots at 1.0±0.06 mJ). The 1 month post-SLT IOP was 13.5±2.8 mm Hg. The percentage of SLT success was 57.1% (28/49). The 95% confidence band by bootstrap method was plotted showing that a total energy between 214.6 and 234.9 mJ significantly decreased the IOP>25%, with the optimal total energy at 226.1 mJ.
A higher SLT energy, in the range of 214.6 to 234.9 mJ, seems to be associated with an improved IOP-lowering response. Further randomized control trials with treatment stratification are needed to confirm these results.
Low-dose transscleral diode laser cyclophotocoagulation (TSCPC) as a potential single treatment for primary open-angle glaucoma (POAG) in Malawi?
- 1University Eye Hospital Tübingen, Tübingen, 72076, Germany, firstname.lastname@example.org.
To investigate if low-dose 810 nm transscleral cyclophotocoagulation (TSCPC) can be used as single treatment in Malawianglaucoma patients.
Forty-seven eyes of 28 patients with primary open-angle and pseudoexfoliation glaucoma were treated with TSCPC using 12 spots with 900 mW, 2,000 ms (1.8 J per spot); six spots in the upper half, six in the lower by sparing the 3 and 9 o’clock positions ±20°. Intraocular pressure (IOP) and uncorrected visual acuity (UVA) were measured by an independent examiner preoperatively, on the first postoperative day, after 2 weeks, and after 3 months.
Twenty-four (86%) and 18 (64%) of 28 patients (31 of 47 eyes; 66%) completed follow-up at 2 weeks and at 3 months respectively. After a single treatment session, IOP decreased by at least 25 % in 88% (21 of 24) after 2 weeks, and in 50% (nine of 18) of patients after 3 months. Mean IOP was 38.5 mmHg before TSCPC, 23.5 mmHg (p < 0.001) after 1 day, 24.5 mmHg (p < 0.001) after 2 weeks, and 35.6 mmHg (p = 0.37) after 3 months. In three patients, however, IOP increased after 3 months to levels significantly higher than before TSCPC.
Low-dose TSCPC caused a significant IOP lowering for up to 2 weeks (15 mmHg less from baseline) in most patients. After 3 months, this effect was stable in 50% of patients; in the other half, IOP nearly returned back to baseline.
The efficacy of low-energy selective laser trabeculoplasty.
Shanghai Jiaotong University Affliated First People’s Hospital, Ophthalmology, Shanghai, China.
BACKGROUND AND OBJECTIVE:
to analyze the efficacy of low-energy selective laser trabeculoplasty (SLT) in patients.
PATIENTS AND METHODS:
in 74 patients (74 eyes) with ocular hypertension, suspected glaucoma, or primary open-angle glaucoma, SLT was the first-choice treatment. Thirty-nine patients in the low-energy group received treatment using half of conventional laser energy over 360° of the trabecular meshwork (at 100 points). Thirty-five patients in the control group received conventional laser energy. Patients were observed for 1 year. Complications and intraocular pressure (IOP) were observed.
postoperative transient IOP spike ( 3 mm Hg) occurred in three eyes on the day of treatment and partial peripheral anterior synechiae occurred in one eye 1 month after treatment only in the control group. Effective rates of treatment (20% IOP reduction) at week 2 and month 1, 3, 6, and 12 after treatment were 69.23%, 64.10%, 61.54%, 53.85%, and 48.72% in the low-energy group and 71.43%, 71.43%, 60%, 51.43%, and 48.57% in the control group, respectively. There was no statistically significant difference between the two groups at various time points (P = .836, .501, .892, .835, .990).
compared with SLT using conventional laser energy, low-energy SLT lowers IOP with fewer complications, making it a safe and effective option.
Vopr Kurortol Fizioter Lech Fiz Kult. 2009 Nov-Dec;(6):27-9.
Comparative hemodynamic characteristics of patients with the organ of vision subjected to low-intensity laser radiation of the green and red wavelengths.
[Article in Russian]
Kamenskikh TG, Ragorodski IuM, Kolbenev OI, Galanzha A, Orlova AS, Kamenskikh ID.
This comparative study was designed to evaluate effect of low-intensity speckle laser radiation in the green and red wavelengths on intraocular hemodynamics in 202 patients (202 eyes) with retinal vascular problems and without them. Irradiation was performed using “Izumrud” and “Rubin” adapters for an AMO-ATOS unit. Peak systolic velocity and peripheral resistance index in posterior short ciliary arteries and central retinal artery were measured. It was shown for the first time that green speckle laser radiation (wavelength 535 nm) has more pronounced (compared with the red light) effect on intraocular hemodynamics; thereby, it makes a greater contribution to the improvement of the visual function (e.g. in the case of glaucoma) and to the widening of the fields of vision.
Photomed Laser Surg. 2009 Jun 10. [Epub ahead of print]
Early Diagnosis of Ocular Hypertension Using a Low-Intensity Laser Irradiation Test.
Ivandic BT, Hoque NN, Ivandic T.
1 University of Heidelberg, Otto-Meyerhof Centre , Heidelberg, Germany .
Objective: We investigated the potential use of low-intensity laser irradiation (LILI) as a diagnostic tool for identifying hypertensive eyes at risk of glaucoma.
Background data: The diagnosis of early-stage ocular hypertension is particularly difficult to establish.
Methods: This study of a case series included 123 healthy subjects with normal vision. The intraocular pressure (IOP) was determined before (baseline) and 30 min after a 30-sec irradiation of the limbus area with laser light (780 nm; 7.5 mW; 292 Hz modulation).
Results: Baseline IOP was >21 mm Hg in 44 of 211 eyes (20.9%), consistent with ocular hypertension. LILI decreased the mean IOP by 6.2 mm Hg (-25.7%; p < 0.001; paired t test) in these eyes. The remaining 167 eyes (79.1%) exhibited a normotensive IOP </=21 mm Hg. LILI reduced the mean IOP by 2.9 mm Hg (-17.1%; p < 0.001) in these eyes, but there were different response patterns: 1) the IOP did not change (27.0%); 2) the IOP was reduced by the same extent in both eyes (32.3%); 3) initial IOP differences between left and right eyes became level and the absolute IOP was reduced to a lower level that was identical in both eyes (18.0%); and 4) the initial difference in IOP between the left and right eye persisted despite LILI (22.7%).
Conclusion: LILI lowers IOP, even in normotensive eyes. This effect may be useful to determine the individual physiological IOP and to diagnose latent ocular hypertension in eyes with presumably normotensive IOP.
Lasers Med Sci. 2008 Jan 29 [Epub ahead of print
Experimental study on low pulse energy processing with femtosecond lasers for glaucoma treatment.
Hou DX, Butler DL, He LM, Zheng HY.
Precision Engineering and Nanotechnology Centre, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore, email@example.com.
The feasibility of low energy processing in ocular tissues with femtosecond laser sources was investigated in this research. One laser source was a femtosecond amplifier, and the other was a femtosecond oscillator. The amplifier used in this experiment was a CPA-2001 (Clark-MXR, Inc), with 150 fs pulse duration and 1 kHz repetition rate. The femtosecond oscillator (model 900-B Mira) produced a 200 fs pulse duration and a 76 MHz repetition rate. Both these two laser systems operated at 800 nm wavelengths. Firstly, the pulse intensity thresholds in water produced by the two laser sources were compared. The optical breakdown probability analysis shows that the pulse energy threshold achieved by the oscillator was less than 10% of that achieved by the amplifier. Then, the non-linear propagation of the femtosecond pulses in the ocular tissues was studied with the femtosecond oscillator. The results showed a potential for pulse energy processing at the nanojoule level with a femtosecond oscillator in glaucoma treatment.
Vestn Oftalmol. 1998 Nov-Dec;114(6):6-9.
Heparin inhalations and laser exposure of blood in treatment of patients with open-angle glaucoma
[Article in Russian]
Balashova LM, Listopadova NA, Zaitseva NS, Teplinaskaia LE, Efimov VS, Grishin VL, Kantarzhi EP.
Comparative assessment of methods aimed at amelioration of the immunohemostatic processes in patients with open-angle glaucoma suffering from chronic vascular diseases showed that the most remarkable improvement of the visual functions and decrease of the level of circulating immune complexes in the blood were attained in the patients treated by heparin inhalations combined with intravenous laser exposure of the blood as against patients treated by one of these methods alone or traditionally.
The comparative analysis of using lowpower laser radiation, magnetic therapy and electrical stimulation in stabilization of visual functionc in primary open-angle glaucoma.
Listopadove N A et al.
127 men with a primary open-angle glaucoma(POAG) were treated with either L/LT, magnetic therapy or electrical stimulation. The examination included visus, visocontrastometry and automatic static perimetry. The field of sight at an initial stage of POAG was 56% of laser, 52 for magnetic therapy and 27 for electrical stimulation. In the advanced stage the figures were 39, 37 and 18, respectively.