Abstract
Introduction
We present two cases of vitreous hemorrhage after micropulse cyclophotocoagulation one of which had concurrent hyphema. To the best of our knowledge, these are the first cases of vitreous hemorrhage due to micropulse CPC in the United States.
Case description
The first case is an 82-year-old woman with bilateral severe primary open angle glaucoma. BCVA in the right eye was 20/25, and 10-2 Humphrey visual field showed severe peripheral defects. The patient underwent MPCPC of the right eye and at one week, a settled 2 mm hyphema and vitreous hemorrhage confirmed by B-scan were noted. At three months, the patient had a BCVA of 20/80 with an IOP of 12 and retina consultation deferred a PPV. The second case is of a patient with bilateral moderate stage POAG who underwent MPCPC in both eyes. His original VA was 20/200 bilaterally. At 2 weeks, RE VA was count fingers at one foot and LE was 20/150-1. At two months, a RE B scan revealed dense vitreous opacities. Retina consultation revealed vitreous hemorrhage but a PPV was deferred.
Conclusion
Clinicians should be aware of the risks of bleeding and the potential need for additional surgical interventions after MPCPC.
Keywords
Introduction
Transscleral cyclophotocoagulation (CPC) is a widely utilized procedure in which diode laser energy is used to ablate the ciliary body and reduce aqueous humor production. Traditional CPC administers a continuous wave of laser energy with reported vision-threatening complications that include prolonged hypotony, phthisis bulbi, and sympathetic ophthalmia. 1
In comparison, micropulse CPC (MPCPC) is a noncontinuous mode of delivery that offers fewer side effects. In MPCPC, laser is applied in a cyclic fashion with pulses of energy (“on” cycles) interrupted by pauses (“off” cycles). This technique minimizes the risk of damage to treated tissues likely because it does not allow sufficient accumulation of energy in tissues adjacent to the pigmented epithelium of the ciliary body, such as the non-pigmented epithelium, preventing unnecessary damage. 2
We report 2 cases of vitreous hemorrhage after MPCPC. First, is a case of an 82-year-old female who presented with decreased vision, hyphema, and vitreous hemorrhage after MPCPC. The second is a case of a 51-year-old man with a history of congenital hydrocephalus who presents with decreased vision, severe conjunctival injection, and vitreous hemorrhage after MPCPC. To the best of our knowledge, these are the first cases of vitreous hemorrhage due to micropulse CPC in the United States.
Case report
Case 1
An 82-year-old Hispanic female presented for evaluation of severe primary open angle glaucoma (POAG) in her right eye. Her ocular history included severe POAG in both eyes and myopia (−5.0 D) in both eyes. She had previously undergone selective laser trabeculoplasty in both eyes in 2016 and 2018 as well as cataract extraction with posterior chamber intraocular lens (PCIOL) placement in both eyes in 2018. Her medical history was notable for type 2 diabetes mellitus, asthma, and dyslipidemia. She was not on any anti-coagulation or anti-platelet medications.
For her severe POAG, her topical IOP-lowering medications included brinzolamide/brimonidine three times a day and bimatoprost at night in both eyes. For the right eye, visual acuity was 20/25 with IOP of 19 mmHg. Her exam was notable for PCIOL in both eyes and lack of neovascularization of the angle or neovascularization of the iris in either eye. Dilated fundus exam showed a cup-to-disc ratio (CDR) of 0.9 with rim thinning and no signs of diabetic retinopathy. Humphrey visual field 10-2 showed severe peripheral defects in the right eye. Given her small island of vision in the right eye, preserved visual acuity, IOP above a target for extent of disease, and aversion toward trabeculectomy or tube shunt surgery, she underwent MPCPC.
Preoperatively, the patient was given a peribulbar block of 2% lidocaine. The procedure was performed at 2500 mW with a duty cycle of 31.3%, 10 s per quadrant sweep, 4 sweeps per quadrant in all four quadrants (total 160 s), sparing the 3- and 9-o’clock meridia. No sub-Tenon steroid injection was given intraoperatively. After the procedure, the patient was instructed to use topical prednisolone acetate 1% ophthalmic suspension four times daily for one week.
At the one-week post-operative visit, the patient's vision decreased to light perception with an IOP of 15. Exam was notable for a settled 2 mm hyphema and significant dispersed blood with clots along the surface of her PCIOL with no view to the retina and a dense vitreous hemorrhage confirmed by B-scan ultrasonography. Cyclopentolate 1% two times daily was added to her topical drop therapy regimen and prednisolone drop therapy was continued four times daily. She was instructed to sleep upright. After two weeks of persistent hyphema and clots on the PCIOL, she underwent an anterior chamber washout.
After three months of follow-up, final best-corrected visual acuity remained at 20/80 with an IOP of 12 mmHg. The vitreous hemorrhage began to clear, and retina consultation deferred a pars plana vitrectomy. Cyclopentolate and prednisolone drops were discontinued while brinzolamide/brimonidine and bimatoprost were continued.
Case 2
A 51-year-old man presented for management of moderate stage primary open angle glaucoma. The patient's medical history includes developmental delay, congenital hydrocephalus managed with a ventriculoperitoneal shunt that has undergone multiple revisions due to shunt infections, seizure disorder managed with anti-seizure medications, and hypertension. Ocular history includes, bilateral optic nerve atrophy secondary to hydrocephalus, bilateral primary open angle glaucoma, nystagmus, bilateral high myopia, as well as bilateral age-related nuclear cataracts.
The patient was on brimonidine/timolol both eyes twice a day as well as bimatoprost in both eyes at night. The patient's mother reported that adherence to the regimen has been difficult as the patient squeezes his eyes shut during application of drops. Despite encouraging adherence as well as management with a 3-medication regimen, the patients IOP's remained uncontrolled (up to 25 and 28 mmHg in the RE and LE). VA was 20/200 bilaterally. Given the elevated IOP in the setting of challenging adherence with medical therapy MPCPC was recommended.
MPCPC was performed in the RE followed by the LE at 2000 mW. Each of the 4 quadrants was treated for 40 s with a duty cycle of 31.3%. 3 o’clock and 9 o’clock positions were avoided. After the procedure, pred forte and cyclopentolate were placed in both eyes. The patient was discharged with cyclopentolate HCl 1% three times a day both eyes and prednisolone acetate 1% four times a day both eyes. The patients original brimonidine/timolol and bimatoprost were continued.
At one week follow up, the patient had difficulty seeing out of the right eye with no subjective VA changes in the LE. He reported pain and redness in the right eye as well as occasional pain in the left. His mother reported that she was only able to use medications a few times since the procedure. VA was CF at 1 foot in the RE and 20/150 in the LE. IOP's were 18 and 16 in the RE and LE respectively. SLE showed 3 + injection of the right eye with 4 + flare, 2 + cell, and fibrin in the anterior chamber. Left eye showed 2 + cell and 2 + flare. B- scan of the right eye at this visit showed no retinal or choroidal detachments but showed thickening of the choroid. Cyclopentolate was changed to twice per day and the patient was requested for follow up in one week.
At 2 week follow up, RE VA continued to remain at CF at 1 foot and LE VA was 20/150-1. IOP was 11 and 14 in the right and left eyes respectively. SLE now showed 2 + injection of the right eye with 2 + cell and 2 + flare. LE also had 2 + cell and 2 + flare.
At 2 months of follow up, the VA was HM in the right eye and 20/100 in the left eye as well as IOP's of 11 and 12 respectively. Inflammation in the right eye was improving. A B-scan of the right eye at this visit revealed dense vitreous opacities and no retinal detachment. There was improvement of the previous choroidal thickening. The patient was referred to retina for evaluation in order to determine if a pars plana vitrectomy would aide in visual recovery.
At the retina appointment 10 days later, the patient was noted to have a vitreous hemorrhage with no evidence of a retinal detachment or tear in the right eye. A B-scan revealed a vitreous hemorrhage with no choroidal detachment in the right eye. VA at this appointment was improved to 20/200 in the RE and 20/150 in the LE with IOP's of 10 and 13 respectively. C/D ratio was 0.9 and 0.8 respectively in the RE and LE. Pars plana vitrectomy was deferred and the patient was continued on prednisone, now three times a day bilaterally, and ketorolac tromethamine.
Conclusions
While micropulse CPC lasers have an improved side effect profile when compared to continuous CPC, complications of this procedure have been noted in the literature. The most common complications noted are anterior chamber inflammation, mydriasis, hypotony, macular edema, loss of BCVA, corneal edema, phthisis bulbi, superficial punctate keratitis, and conjunctival hemorrhage in no particular order.1,3,4 Vitreous hemorrhage is a rare postoperative complication of non-incisional ciliary ablation surgeries and has been mainly described in cases rather than large studies. Further, non-clearing vitreous hemorrhage after cyclodestructive surgeries typically does not occur in isolation and, instead, has been associated with coexisting rhegmatogenous retinal detachment or suprachoroidal hemorrhage.5,6 As such, we believe these are the first cases of vitreous hemorrhage, especially in the context of hyphema, secondary to MPCPC in the United States.
Similarly, hyphema itself is an infrequent complication of micropulse cyclophotocoagulation. One study reported 3 cases of hyphema among 84 eyes (3.6%) treated with MPCPC. 7 These hyphemas were small and self-resolving. 7 Though, it was unclear from the reported literature if these patients were more susceptible to bleeding due to risk factors such as anticoagulant medication use. Indeed, anticoagulant therapy has been associated with significant hyphema requiring an anterior chamber washout. 8 Although significant hyphema is very rare, such a finding may be reported in the setting of intraocular bleeding, such as concurrent choroidal hemorrhage. 6
Our patients did not have a history of trauma or anticoagulant or antiplatelet therapy. After the procedure, neither patient was found to have significant retinal or choroidal complications. Case 1 had moderate myopia and reported a history of well-controlled diabetes without evidence of diabetic retinopathy. Given that diabetes is known to cause significant vascular changes, we speculate that diabetics may be more susceptible to intraocular bleeding even in noninvasive cyclodestructive procedures, such as micropulse cyclophotocoagulation. Case 2 in our study had hypertension. Indeed, some studies have suggested that systemic diseases, such as diabetes and hypertension, may be an underlying risk factor for vitreous hemorrhage. 9 A review article conducted by Sanchez et al. in 2018 attempted to outline guidelines for dosage of energy in joules supplied by the micropulse CPC during the procedure based on complication rate. 2 They found that complications from the procedure rose significantly when the dosage exceeded 150 joules. 2 Our first patient underwent exposure to 125.2 joules (160 s×2.5 W×.313) which fell within the “good balance” category within the study representing the best balance of efficacy and safety. 2 Case 2 had 2 W used during MPCPC and so even less energy (100.16 joules) was used. As such, another underlying factor is also likely contributing to our patient's vitreous hemorrhage and hyphema. IOL status is a factor that could be explored as the presence of a malpositioned IOL is well known to cause hyphema and vitreous hemorrhage as part of UGH syndrome. 10 Our patients differed with respect to IOL status but this factor has not been reported in the literature as a risk factor for vitreous hemorrhage or hyphema in the context of MPCPC alone. Further exploration is warranted to identify the role of IOL status on secondary effects of MPCPC.
We conclude that although micropulse cyclophotocoagulation has an improved safety profile compared to other cyclodestructive procedures, clinicians should be aware of the risks of bleeding and the potential need for additional surgical interventions.
Footnotes
Consent
Verbal consent to publish was provided by the patient.
Declaration of conflicting interests
The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: I Albert Khouri, am reporting that I am a consultant to Glaukos, Alcon, and Bausch & Lomb, companies that may be affected by the research reported in the enclosed paper. I am also on the speaker bureaus for Abbvie and Bausch & Lomb. I have fully disclosed those interests fully and have in place an approved plan for managing any potential conflicts arising from this arrangement.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
