Preferred practice patterns for safe cataract surgery in the presence of lacrimal and eyelid pathologies

Fluorescein dye disappearance test (FDDT)

Fluorescein dye disappearance test (FDDT) is considered a simple, reliable and effective test for assessment of NLDO in adults.^[10] The test is performed by staining the tear film with a fluorescein strip and observing the remaining tear meniscus height by cobalt light of an indirect microscope. Based on the time duration of the assessment, the test could either be 2-FDDT (2 min), 5-FDDT (5 min) or 10-FDDT (10 min).^[11,12] MacEwen and Young gave the modified FDDT grading (originally described by Zappia and Milder),^[13] that is Grade 0 (no fluorescence in the conjunctival sac), Grade 1 (thin fluorescein marginal tear strips only), Grade 2 (between 1 and 3) and Grade 3 (wide and bright fluorescein strip). Negative FDDT includes grade 1 or 0 whereas positive FDDT includes grades 2 and 3. A sensitivity and specificity of 82.8% and 91.4%, respectively, has been proven for 2-FDDT, and 5-FDDT has a sensitivity and specificity of 71.1% and 94.8%, respectively.^[12]

Regurgitation on pressure over the lacrimal sac (ROPLAS)

A simple test of gentle pressure over the lacrimal sac can give us an indication of lacrimal sac disease. As per Thomas et al., Regurgitation on pressure over the lacrimal sac (ROPLAS) has a sensitivity and specificity of 93.2% and 99.3%, respectively.^[14] Whereas Kim et al. have reported a sensitivity of 54.5%, and a specificity as high as 100%.^[15] The data states that the presence of ROPLAS is a definite indication of an underlying lacrimal disease; however, its absence cannot exclude the possibility of NLDO.

Lacrimal irrigation

Lacrimal irrigation is the anatomical gold standard diagnostic test to assess NLDO. Preferably this test should be carried out by the oculoplastic surgeons; however, if the technique is adopted the right way, ophthalmologists from any sub-specialty can assess lacrimal patency using this method. After anesthetising the conjunctiva, the patient is made to recline or lie down, and an appropriately sized 15° curved cannula or straight cannula is fitted to a syringe with sterile water or normal saline. The patient is asked to look down (for upper punctum) or up (for lower punctum). Peripunctal stenosis is noted, and Nettleship punctum dilator is used for punctum dilatation. Probing is performed to assess the canaliculus and the cannula is then inserted vertically followed by horizontally. After reaching the horizontal canaliculus, preliminary intra-canalicular irrigation is performed, and then the cannula is advanced into the sac, and gentle irrigation is performed. If the fluid reaches the throat, it indicates patency. If there is a regurgitation of fluid, the site and type of discharge should be noted as it indicates the site of the blockage.^[16]

Guzek et al. have stated that for a definitive diagnosis, more than one lacrimal tests are suggested in patients with epiphora.^[17] Therefore, a detailed clinical assessment, along with the tests mentioned above, with accurate interpretation [Table 1] must be performed preoperatively before posting the patient for cataract surgery. The symptomatic patients should be referred to oculoplastic surgeons for further intervention and cataract surgery should be performed ideally 4 weeks (acceptable) to 6 weeks (ideal) after the lacrimal surgical correction.^[8] Simultaneous bilateral surgeries are preferably avoided, and if the other side has NLDO, it is ideal to perform contralateral dacryocystorhinostomy before cataract surgery.^[5] In case performing cataract surgery is an emergency (in situations such as lens-induced glaucoma), dacryocystectomy with punctal cautery should be preferred, or punctal plug/punctal cautery/surgical punctal closure/cyanoacrylate glue sclerotherapy should be performed before cataract surgery.

Eyelid malposition

If the patient has mild entropion or ectropion, it is advisable to proceed with cataract surgery. However, if severe, then eyelid correction is advisable before cataract surgery.

Eyelash abnormalities

In cases with trichiasis or distichiasis, before cataract surgery, epilation with the help of electrolysis with or without cryotherapy must be performed.

Lagophthalmos

If there is no significant corneal exposure, then cataract surgery can be performed. However, vision restoration can be at stake if lagophthalmos is not corrected, causing corneal damage.

Ptosis

A ptosis of >4 mm affects the power calculations for the intraocular lens (IOL), thus affecting the final visual outcome; this is due to the change in corneal contour and surface remodelling. Therefore, ideally, ptosis correction should be performed before the cataract surgery to relieve the pressure on the cornea and cause regression of the anterior corneal surface to its original anatomy.^[19,20] It is advisable to keep a gap of at least 6 weeks between the eyelid correction and toric or multifocal IOL insertion. In cases with mild ptosis, observation for the lid height can be adopted, and reassessment should be performed 3 months after the cataract surgery.