4 Prevention and treatment
For patients under taxane administration, it is recommended to have a
baseline examination of ophthalmology before treatment, such as visual
acuity, intraocular pressure, fundus, color vision, visual field
examination, and etc. and to closely observe whether there are new
ocular symptoms during the treatment process. Patients with ocular
symptoms in the course of medication should be referred to have ocular
consultancy and have a complete ocular checkup in time. For the ocular
surface diseases caused by paclitaxel drugs, such as dry eye,
conjunctivitis, keratitis, and etc. Usually, we recommend to use
artificial tears, non-steroidal anti-inflammatory drugs, antibiotic eye
ointment and other symptomatic treatment. Lacrimal duct obstruction or
narrow, tear overflow can be used lacrimal duct irrigation or lacrimal
duct exploration [19]. The adverse side effects occur on the ocular
surface caused by paclitaxel are reversible and can be recovered after
withdrawal and symptomatic treatment, with within several days to 5
months [19].
For patients with macular edema and impaired vision, there are no
authentic treatment guidelines. The main treatment strategy is to stop
chemotherapy, but this option should be mainly determined by the
systemic status. Some scholars have tried to use carbonic anhydrase
inhibitors, glucocorticoids and anti-vascular endothelial growth factor
drugs for treatment. Ehlers et al. [29] showed that topical use of
2% carbonic anhydrase inhibitors could effectively remission
paclitaxel-associated macular edema and improve visual acuity after the
cessation of chemotherapy, suggesting that carbonic anhydrase inhibitors
might be used as an early treatment option. Glucocorticoids are also
being considered. In cases that dexamethasone was injected
intravitreally, the retinal thickness of the patient decreased after 1
month, but the macular edema persisted and the presence of macular edema
disappeared significantly after 2 months of discontinuation of
chemotherapy [30]. The similar finding was also observed in cases
subjected to sub-Tenon injections of triamcinolone acetonide, suggesting
that glucocorticoids may merely relieve rather than resolve the problem
[31]. Anti-vascular endothelial growth factor drugs, a widely
adopted drug in treating diabetic macular edema, seemed has little
effect to paclitaxel-induced macular edema. In Rahman’s study,
continuous binocular intravitreal bevacizumab resulted in stable vision
but persistent macular edema [32], which reveals the different
mechanisms of taxanes induced macular edema from diabetic macular edema
and retinal vein occlusion-macular edema. In addition, some researchers
have found that carvone protects against paclitaxel-induced retinal and
optic nerve cytotoxicity in rats[33], while further studies remain
to be carried out.