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A disease causing epiphora due to obstruction of the lacrimal canaliculus or common canaliculus. Causes include inflammatory scarring, drug-induced (S-1), trauma, and post-infection. Dacryoendoscopic tube insertion is the first choice; for cases that cannot be recanalized, CDCR or dacryocystorhinostomy with canalicular bypass is indicated.

Explains the device specifications, indications, examination procedure (anesthesia methods and insertion technique), normal and abnormal findings, applications in treatment (DEP/SEP/SGI), and complications of dacryoendoscopy.

Explanation of the types, symptoms, diagnosis, and treatment of tumors that occur in the lacrimal gland. This overview covers the characteristics and management strategies for each classification, from epithelial tumors such as pleomorphic adenoma (about 70% of lacrimal gland epithelial tumors) and adenoid cystic carcinoma to malignant lymphoma.

Explains the indications and procedure for lacrimal irrigation, how the irrigation needle is chosen, how to interpret the results (estimating the site of obstruction), the dye disappearance test, and its role in congenital nasolacrimal duct obstruction.

A general term for benign and malignant tumors arising in the lacrimal sac. Epithelial tumors are the most common, with about 55% being malignant. It is often misdiagnosed as chronic dacryocystitis, and delayed diagnosis leads to poor prognosis.

Lacrimal tube intubation is a surgery to recanalize the lacrimal pathway by placing a silicone tube in cases of obstruction or stenosis of the punctum, canaliculus, or nasolacrimal duct. Tube insertion using DEP/SEP perforation under dacryoendoscopy and SGI has become widespread, with a long-term survival rate of 94% for grade 1 canalicular obstruction. Complications include cheese-wiring, submucosal misinsertion, and granulation formation.

Lagophthalmos is a condition in which the eyeball is exposed due to incomplete eyelid closure, caused by facial nerve palsy, scarring, proptosis, etc. There is a risk of progression from corneal epithelial damage to perforation, and management is staged from conservative treatment to surgical intervention.

Langerhans cell histiocytosis (LCH) is a rare disease characterized by clonal proliferation of Langerhans cells, with proptosis due to osteolytic lesions of the orbital bone as the main symptom. It commonly occurs in children, with an incidence of 2 to 9 per million people.

This article explains the pathology, symptoms, diagnosis, and treatment of eye injuries caused by laser pointers, cosmetic lasers, and medical lasers. Various disorders can occur, including photothermal and photomechanical retinal damage, as well as choroidal neovascularization.

Objective quantitative measurement of anterior chamber protein concentration using a laser flare meter. Useful for monitoring inflammatory activity in uveitis and evaluating inflammation after cataract surgery. Explained together with SUN grading criteria.

Explanation of indications, procedure, laser settings, complications, and treatment outcomes of laser peripheral iridotomy (LPI). Includes evidence from ZAP trial and EAGLE trial, differentiation between Nd:YAG laser and argon laser, and rare complications (decompression retinopathy, ciliochoroidal detachment).

Explains the safety standards, hazard classification, clinical features, diagnosis, and management of laser injuries used in ophthalmology, as well as safety measures for the environment, patients, and operators.

This article explains the principles, indications, technique, lenses used, laser settings, complications, and timing of laser suture lysis (LSL) after trabeculectomy. It includes the latest knowledge on stepwise adjustment of filtration volume in postoperative intraocular pressure management.

Explanation of the principles, indications, irradiation conditions, procedures, complications, and treatment outcomes of laser trabeculoplasty (ALT/SLT). Includes details of the 6-year results of the LiGHT trial, positioning in the 5th edition of the Japanese Glaucoma Guideline and the 6th edition of the EGS, and usage in exfoliation glaucoma.

This article explains the principles, techniques, efficacy, and safety of excimer laser trabeculotomy (ELT) and femtosecond laser image-guided high-precision trabeculotomy (FLIGHT). It also includes their positioning in MIGS and future prospects.

An outpatient procedure using Nd:YAG laser to vaporize and break up vitreous opacities (floaters). It can provide symptom relief for selected cases of floaters.

LASIK flap complications is a general term for structural, inflammatory, and infectious disorders associated with flap creation, repositioning, and postoperative course in LASIK surgery. This article explains the classification, diagnosis, and management of DLK, flap displacement, epithelial ingrowth, free cap, buttonhole, and others.

LASIK surgery after corneal transplantation is a refractive surgery that corrects residual refractive errors and astigmatism after penetrating keratoplasty (PKP). After PKP, an average of 4–5 D of astigmatism occurs, and LASIK is considered for cases where correction with glasses or contact lenses is difficult. Attention must be paid to the risks of wound dehiscence and graft rejection.

A condition in which a lumboperitoneal (LP) shunt for idiopathic intracranial hypertension (IIH) becomes dysfunctional several years after surgery. It presents with recurrence of headache and visual impairment, and the main treatment is shunt revision or conversion to a VP shunt.

Lattice corneal dystrophy is a hereditary corneal dystrophy in which amyloid deposits in a lattice pattern in the corneal stroma. It is broadly classified into LCD1, an autosomal dominant form caused by TGFBI gene mutations, variant types (e.g., type 3A), and gelsolin type (Meretoja syndrome). It causes recurrent epithelial erosions and progressive vision loss, and PTK and deep anterior lamellar keratoplasty (DALK) are standard treatments.

This article explains the classification, symptoms, diagnosis, and treatment of Le Fort fractures (types I, II, and III), focusing on ophthalmic complications.

The most severe form of congenital retinal dystrophy causing severe visual impairment from birth to infancy. Mainly autosomal recessive inheritance, with over 27 causative genes identified.

An acute to subacute optic neuropathy with maternal inheritance due to mitochondrial DNA point mutations. It predominantly affects young males, causing severe bilateral vision loss and central scotomas. The mt11778 mutation is most common, and visual prognosis is poor, but new treatments such as idebenone and gene therapy are being developed.

Subacute necrotizing encephalomyelopathy due to mitochondrial dysfunction. It causes bilateral symmetrical necrotic lesions in the basal ganglia and brainstem, with onset most common in infancy. Over 110 causative genes have been identified.

A group of complications of the lens capsule that occur after cataract surgery. This article explains three conditions: anterior capsule contraction syndrome (excessive contraction and fibrosis of the capsule), capsular distension syndrome (fluid accumulation within the capsule), and dead bag syndrome (late IOL dislocation due to loss of lens epithelial cells).

A rupture of the posterior lens capsule during cataract surgery. Early recognition and appropriate management are crucial for visual prognosis.

Lens coloboma is a congenital condition in which a partial defect of the zonular fibers causes a notch-like indentation at the equator of the lens. It is associated with incomplete closure of the embryonic fissure and often coexists with iris and chorioretinal coloboma.

A condition in which the lens is displaced from its normal position. It is caused by weakening or rupture of the zonules of Zinn. Congenital cases are associated with systemic diseases such as Marfan syndrome and homocystinuria, while trauma is the most common cause of acquired cases. Mild cases are managed with refractive correction and observation, while advanced cases require lens extraction.

General term for techniques to divide and fragment the lens nucleus during cataract surgery. Multiple procedures exist, such as divide-and-conquer, phaco-chop, and stop-and-chop, selected based on nuclear hardness, surgeon experience, and complication risk.

Classification (phacomorphic, phacolytic, lens-particle, phacoantigenic), pathophysiology, diagnosis, and treatment of lens-induced glaucoma. Includes positioning of secondary glaucoma based on the 5th edition of the Glaucoma Clinical Practice Guidelines, differentiation and management of intumescent cataract, phacolysis, lens cortex, and phacoanaphylactic glaucoma, dosage of hyperosmotic agents, and mechanism of contraindication for miotics.

Classification of lens-induced glaucoma (phacomorphic, phacolytic, lens-particle, phacoantigenic), pathophysiology, diagnosis, and treatment. Includes differentiation and management of phacomorphic glaucoma, phacolytic glaucoma, lens-particle glaucoma, and phacoantigenic glaucoma.

Granulomatous uveitis caused by exposure of lens proteins that have lost immunological privilege within the eye. It is a rare disease triggered by hypermature cataract or capsular rupture due to trauma, and lens extraction is the only curative treatment.

Chronic granulomatous infection caused by Mycobacterium leprae. The eye is frequently affected, and chronic iridocyclitis, iris pearls, corneal lesions, and lagophthalmos are major causes of visual impairment.

Leukemic ocular infiltration can occur in the retina, anterior segment, optic nerve, and orbit. Retinal lesions are found in approximately 70% of all leukemia patients. This article explains Roth spots, pseudohypopyon, optic nerve infiltration, and GVHD-related ocular complications, and summarizes treatment options including radiotherapy, leukapheresis, and systemic chemotherapy.

Optic nerve dysfunction due to direct infiltration by leukemic cells. It is a neuro-oncological emergency, and the mainstay of treatment is a combination of intrathecal chemotherapy and orbital radiation therapy.

Explanation of symptoms, causes, diagnosis, and treatment of leukemic retinopathy. Introduces characteristic fundus findings such as Roth spots and retinal hemorrhages, treatments including radiation therapy and leukapheresis, GVHD-related ocular complications after hematopoietic stem cell transplantation, and the latest imaging diagnosis using OCTA.

Explains symptoms, causes, diagnosis, and treatment of leukemic retinopathy. Introduces characteristic fundus findings such as Roth spots and retinal hemorrhages, treatments including leukapheresis and vitrectomy, and the latest imaging diagnosis using OCTA.

Ptosis surgery is selected based on levator function. When levator function is 10 mm or more, levator advancement (aponeurosis advancement) is standard; when it is less than 4 mm, frontalis suspension is standard. Preoperative MRD-1 measurement, levator function testing, and confirmation of Hering's law are important. Watch for complications such as hematoma, overcorrection, and undercorrection.

A condition in which the uppermost part of the conjunctiva of the upper eyelid (lid wiper) develops epithelial damage due to friction during blinking. It is strongly associated with dry eye symptoms in contact lens wearers.

Explains the impact of lifestyle on the onset and progression of glaucoma. Includes the relationship between intraocular pressure and diet (nitrates, omega-3, vitamin B3), exercise (aerobic exercise, weightlifting, yoga), sleep position, smoking, alcohol, and caffeine.

An intraocular lens (LAL) whose power can be adjusted postoperatively by ultraviolet irradiation after cataract surgery. FDA approved in 2017. An advanced IOL technology that improves refractive accuracy and patient satisfaction.

A pupillary sign in which the light reflex is impaired while the near reflex is preserved. It is caused by afferent pathway defects, midbrain dorsal lesions, efferent pathway defects, and aberrant regeneration, and is observed in conditions such as Adie tonic pupil, Argyll Robertson pupil, and Parinaud syndrome.

An extremely rare conjunctivitis characterized by chronic, recurrent formation of woody-hard fibrinous pseudomembranes on the palpebral conjunctiva, associated with plasminogen deficiency. It may involve systemic mucosal lesions.

A disease in which the limbus, where corneal epithelial stem cells reside, is damaged, leading to loss of corneal epithelial regenerative capacity. Visual impairment occurs due to conjunctival epithelial invasion (conjunctivalization), superficial neovascularization, and corneal opacity.

A rare corneal disease characterized by linear opacities in the corneal stroma. The etiology is unknown, but an autoimmune involvement is suspected. It responds well to steroid eye drops, but may follow a relapsing-remitting course.

A corneal degenerative disease in which cholesterol and phospholipids deposit in the corneal stroma. It is classified into primary (rare) and secondary (associated with corneal neovascularization). Secondary cases often occur after herpetic keratitis or trauma, and treatment mainly involves occlusion of neovascular vessels.

A rare superficial corneal dystrophy caused by heterozygous loss-of-function mutations in MCOLN1 at Xp22.3. Gray, whorl-like, feathery microcysts appear in the corneal epithelium, causing painless progressive blurred vision. First described by Lisch et al. in 1992.

An ocular surface stem cell transplantation procedure in which conjunctival and limbal tissue from a living relative is transplanted for limbal stem cell deficiency (LSCD). It is indicated for bilateral LSCD or unilateral LSCD where the contralateral eye is unsuitable as a donor. Performed under systemic immunosuppression, the ocular surface stabilization rate is reported to be 45–92%.

A parasitic infection of the subcutaneous and subconjunctival tissues caused by the filarial worm Loa loa. It is transmitted by Chrysops flies and is endemic in Central and West Africa. It is characterized by subconjunctival migration of the worm and Calabar swellings. Diethylcarbamazine (DEC) is the first-line treatment.

An anatomical variant in which the zonules extend anteriorly beyond their normal attachment to the lens equator. Estimated prevalence is approximately 2%. Associated with risks of pigment dispersion syndrome, angle-closure glaucoma, and complications during cataract surgery.

The first FDA-approved treatment for Demodex blepharitis. It is an isoxazoline GABA receptor-gated chloride channel inhibitor that induces spastic paralysis and kills Demodex mites. Administer 0.25% ophthalmic solution twice daily for 6 weeks.

This article explains the evaluation of low vision in glaucoma patients, visual rehabilitation, selection of assistive devices, and psychological support. It includes difficulties with reading, mobility, and driving, as well as the effectiveness of low vision care.

This article explains the definition of low vision care, visual function assessment, prescription of assistive devices, assistive equipment provision system, educational options, and welfare support.

Low-dose atropine eye drops (Rijusea® Mini Ophthalmic Solution 0.025%) is the first domestically approved treatment for myopia progression control in Japan in 2024. By antagonizing muscarinic receptors, it suppresses axial elongation and inhibits myopia progression by approximately 50% while minimizing side effects.

An inborn error of metabolism caused by X-linked recessive mutations in the OCRL gene. It is a rare disease in males characterized by the triad of congenital cataracts, glaucoma, intellectual disability, and renal dysfunction.

A multi-organ infectious disease caused by Borrelia spirochetes transmitted through ticks. It has three stages, and ocular symptoms range from conjunctivitis in stage 1 to uveitis, keratitis, and cranial nerve palsy in stages 2 and 3. In Japan, Ixodes persulcatus and Ixodes ovatus are vectors, with northern Japan (mainly Hokkaido) being endemic. It is a Class IV infectious disease under the Infectious Diseases Control Law.

A type of arenavirus that naturally infects rodents. In acquired infections, it causes aseptic meningitis; in congenital infections, it leads to severe neurological sequelae such as chorioretinitis, hydrocephalus, and periventricular calcification.