|Year : 2022 | Volume
| Issue : 2 | Page : 142-146
Role of trans-scleral diode cyclophotocoagulation in refractory glaucoma: A large retrospective study
Nimrita Nagdev, Vidya Raja, Kumar Saurabh, Srilekha Reddy
Department of Glaucoma, at Aravind Eye Hospital, Madurai, Tamil Nadu, India
|Date of Submission||27-Feb-2022|
|Date of Decision||07-Apr-2022|
|Date of Acceptance||11-Apr-2022|
|Date of Web Publication||30-Jun-2022|
Glaucoma Consultant, Department of Glaucoma Services, Aravind Eye Hospital, Madurai - 625 020, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Purpose: To study the efficacy and safety of Trans-scleral Cyclophotocoagulation (TS-CPC) to achieve adequate IOP reduction and a comfortable eye in refractory glaucoma. Material and Methods: The study was conducted at the glaucoma clinic of Aravind Eye Hospital, Madurai (TN). A total of 391 eyes of 317 patients treated from January 2019 – December 2019 with a minimum of 6 months and maximum follow-up up to 1 year were included in the study. Results: The Mean Pre-treatment IOP was 44.01 ± 14.06 mmHg. Mean post-treatment IOP at 1, 3, 6 months and up-to 1 year was 27.09 ± 14.07 mmHg, 22.65 ± 16.95 mmHg, 22.97 ± 16.60 and 22.88 ± 17.03mmHg, respectively. Complications encountered were pain and hypotony (1.7%). Conclusion: With the highest number of cases so far and with a longer follow-up period, we found that Trans-scleral Diode Cyclophotocoagulation is highly effective in lowering intraocular pressure. High success rate and low complication rate combined with portability, durability, and easy to learn technique make this procedure the treatment of choice for refractory and complex glaucoma.
Keywords: Intraocular pressure, refractory glaucoma, trans-scleral diode cyclophotocogulation
|How to cite this article:|
Nagdev N, Raja V, Saurabh K, Reddy S. Role of trans-scleral diode cyclophotocoagulation in refractory glaucoma: A large retrospective study. TNOA J Ophthalmic Sci Res 2022;60:142-6
|How to cite this URL:|
Nagdev N, Raja V, Saurabh K, Reddy S. Role of trans-scleral diode cyclophotocoagulation in refractory glaucoma: A large retrospective study. TNOA J Ophthalmic Sci Res [serial online] 2022 [cited 2022 Aug 10];60:142-6. Available from: https://www.tnoajosr.com/text.asp?2022/60/2/142/349521
| Introduction|| |
Refractory glaucoma is the term used for glaucoma resistant to conventional management. This includes maximally tolerated medical therapy, one or more glaucoma surgeries with or without antimetabolites. Multiple factors contribute to the failure of intraocular pressure control during glaucoma management. Commonly encountered refractory glaucoma's include primary angle-closure glaucoma, neovascular, inflammatory, post retinal surgery, post-traumatic and rare conditions like aniridia, congenital anterior chamber anomalies, etc.
Trans-scleral cyclophotocoagulation (TS-CPC) has been established as an alternative therapeutic modality to tube shunt or augmented trabeculectomy for refractory glaucoma, especially in eyes with poor visual potential. TS-CPC destroys the pigmented and non-pigmented ciliary epithelium along with capillaries in the ciliary processes leading to pigment clumping, coagulative necrosis, and extensive destruction of ciliary muscle with a moderate reduction in vascularity.
Modalities tried for cyclodestruction are laser photocoagulation of the ciliary body using the energy with different wavelengths: Nd-YAG (534nm)/Micro pulse (810nm).,,,,,
The main objective was to study the efficacy and safety of diode laser cycloablation to achieve adequate intraocular pressure (IOP) reduction and maintain the contour of the eye in refractory glaucoma
| Materials and Methods|| |
This was a retrospective study conducted at Aravind Eye Hospital, Madurai (TN) and approved by IRB (RET202000311). 391 eyes of 317 patients treated from January 1, 2019 to December 31, 2019 with a minimum follow up of 6 months and a maximum of up to 1 year was included in the study. Ethics Committee has approved on 19th September 2020.
Glaucoma was labeled refractory if the IOP was above 21 mmHg despite all efforts using medical, surgical, and laser treatment options. The pre-laser assessment included best-corrected visual acuity, slit-lamp bio microscopy of the anterior and posterior segment, IOP measurement using Goldman Applanation tonometer, or Air puff noncontact tonometry in patients with corneal pathology. Gonioscopy was also done in all patients except in patients with corneal pathology. Personal profile including age and gender was also recorded.
All patients except with active infection/inflammation and significant scleral thinning were included in this study. One eyed patient with significantly high IOP, in spite of maximal medical therapy, was treated with TS-DCPC and there was no past history of micro pulse being done in any of the eyes in our study.
TS- CPC was performed using the Iridis Quantal Medical Diode laser with a wavelength of 810 nm. Local anesthesia in the form of sub tenon's anesthesia using 3-4 cc of 2% xylocaine was given initially. Energy settings were 1700-2100 mW for 1500 ms. Laser energy was delivered using the G-probe placed 1.5mm from the limbus. The direction of the probe was parallel to the visual axis. A total of 14-16 laser burns were applied for 180° strictly avoiding 3 and 9 o'clock positions to save the ciliary nerves and vessels. The pop sound of the laser burn was the endpoint.
Oral NSAIDS, topical dexamethasone 0.1% eye drops four times a day for 2-4 weeks after treatment was given. Anti-glaucoma medications were tapered in accordance with the drop in intraocular pressure on subsequent follow-up.
Post TS-CPC treatment - IOP, VA, and AGMs were assessed at 1month, 3 months, and 6 months and during every visit. Topical IOP lowering medications were re-introduced if lOP control was inadequate. TS-CPC was repeated if the IOP was above 22 mmHg after the 4th post-laser week by considering the opposite 180°, it was done for a maximum of three times. The treatment was considered successful if the IOP was between 8 and 21 mmHg with or without topical medication.
| Results|| |
A total of 391 eyes of 317 patients (243 males (62.2%) and 148 females (37.8%) were enrolled in this retrospective study. TS-CPC was done in refractory cases of glaucoma, Neovascular (102) being the highest as demonstrated in [Figure 1].
Baseline visual acuity, intraocular pressure, number of AGMs was documented every 1 month, 3 months, 6 months and 1 year.
Mean visual acuity in refractory cases of Neovascular Glaucoma (NVG) (25.6%), Primary Angle Closure Glaucoma (PACG) (22.1%), Primary Open Angle Glaucoma (POAG) (15.3%) and Pseudoexfoliation Glaucoma (PXFG) (6.5%) remained same through the study period with P < 0.001 as shown in [Figure 2] and [Table 1] and with a median difference in vision between visits which was statistically significant and rest of comparision was not statistically significant ([Table 1.1] with P <0.05). However, 25 patients (6%) lost their vision due to uncontrolled IOP and advanced glaucomatous disc damage. The mean IOP, i.e., 44.01 ± 14.16mmHg, decreased to 22.88 ± 17.03 mmHg by end of 1 year as shown in [Table 2]. A significant IOP reduction was noted at 3 months and thereafter with P < 0.001 [Table 2] and with a mean difference in IOP between the visits were statistically significant ([Table 2.1] with P<0.05). The PACG group showed a significant IOP drop to 15.7mmHg since the last visit [Figure 3]. Absolute success was defined as a final IOP of 21 mmHg or less with topical medications at 1-year follow-up and was achieved in 79 patients.
|Figure 2: Line chart for the mean logMAR of visual acuity in each time period with diagnosis|
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|Figure 3: Line chart for the mean IOP in each time period with diagnosis|
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The mean number of Antiglaucoma medications was same by end of 1 year with P<0.001 [Table 3] and the mean difference in Antiglaucoma medications between the visits were statistically significant ([Table 3.1] with P<0.05). Post TS- CPC, anti-glaucoma medications (AGMs) were titrated depending on intraocular pressure, disc damage and type of refractory glaucoma on every follow up.
By 1 year, PACG (13.5%) cases were having no AGM and PXFG (40%) were on only 1 AGM [Figure 4]. A total of 20 patients were refractory to IOP reduction after TS-DCPC, most were in the PACG group (nine cases) due to uncontrolled eye pressures, followed by POAG (3), NVG (2), Post VR secondary glaucoma (2), and 1 each case for PXFG, developmental, uveitic and congenital glaucoma [Figure 5]. TS-DCPC was repeated three times up to 6 months.
|Figure 4: Bar graph for the usage of no. of AGM in each time period based on diagnosis|
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The most common complications in our study were pain and hypotony, post TS-DCPC.
7 patients had hypotony (4 PACG, 1 NVG, 1 Post VR Sx, and 1 Post Keratoplasty) [Figure 6]
NSAIDs were given to relieve pain and for hypotony, all AGMs were stopped and Steroid-antibiotic eye drops along with mydriatics was prescribed. An early review date with close follow up was given for these patients.
Other complications such as vitreous hemorrhage, severe dry eye, hyphema, band shaped keratopathy, and anterior uveitis were encountered. Although, It was not clear the cause of these complications (whether due to TS-CPC or because of the pathology of eye)
| Discussion|| |
Cyclodiode photocoagulation is delivered in patients with uncontrolled IOP despite maximum medical therapy and repeated surgical interventions with significant visual field loss on Humphrey field analysis. Diode laser cycloablation has developed an acceptable track record for the treatment of refractory glaucoma.,,,
TS-CPC is currently a widely employed method of ciliary body ablation that reduces aqueous humor formation by destroying the ciliary body and ciliary epithelium using a continuous diode laser energy source.
It has also been tried as a primary surgical treatment in different types of glaucoma.,,
TS-CPC is considered an ideal method for a few glaucoma patients with very high presenting IOP, before undergoing surgery to avoid incisional intraoperative and post-operative complications (E.g. – Aqueous Misdirection, Suprachoroidal hemorrhage). It is considered as last therapeutic option especially in painful blind eyes. Extent of ciliary body treatment, the total amount of delivered energy, and the use of postoperative anti-inflammatory medications are likely to impact overall efficacy and safety outcomes.,,
TSD-CPC is portable and quick procedure as it can be performed at the bedside. It preserves superior conjunctiva for future surgeries, by applying the laser in lower 180 degree quadrant.
This is a retrospective study with huge number of sample size (391) compared to other literature studies with long follow up visit i.e., up to 1 year and patients are still following till present date.
Visual acuity, IOP, number of AGMs and Optic disc progression was noted on every visit. IOP was not recorded in six patients with total corneal opacity, bullous keratopathy, and cases with decompensated corneas.
The mean IOP reduced to 22.65 ± 16.95 after 3 months up-to 1 year post TS-DCPC treatment. Similar sustainability of the mean IOP reduction postoperatively is also reported by Kosoko et al.
Complications profile is acceptable and most authors have reported insignificant and transient complications like pain and inflammation.,,
Despite its proven efficacy, the utility of this treatment modality in achieving IOP control has often been eclipsed by unpredictable responses as well as its potential adverse effects of persistent hypotony and the dreaded complication of phthisis bulbi.
In our study, only nine cases (1.7%) of hypotony were reported, highest being PACG (four cases) group whereas Murphy et al. found a higher risk of hypotony in eyes with NVG (14/80 eyes) with mean follow up of 17 months.
Other complications such as vitreous hemorrhage, severe dry eye, hyphema, band shaped keratopathy, and anterior uveitis were encountered.
Although, It was not clear regarding the cause of these complications (whether due to TS-CPC or because of pathology of eye)
Retreatment rate at 5.1% (20/391) was much lower that 15.4% (11/71) documented by Kaushik et al.
| Conclusion|| |
TS-CPC is found to be effective in lowering IOP in all refractory glaucoma. Based on efficacy, the rate of CPC may be expanding to lessen the severity of glaucoma and better control of progression to an end-stage.
By focusing on IOP alone, TS-DCPC appeared to be effective up to final follow-up with great success in our study.
In patients with potentially grave complications due to glaucoma surgeries, treatment with diode CPC offers a very effective way to lower IOP.
We acknowledge Dr Kumuragurupari, M Phil, PhD, chief librarian for all the support.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2], [Table 3]