Scleral Lens Fitting After Resolved Corneal Hydrops
Melissa Barnett, OD, FAAO, FSLS, FBCLA
Corneal hydrops is caused by the acute disruption of Descemet's membrane in eyes with corneal ectasia. The term hydrops refers to an abnormal accumulation of fluid in a body tissue or cavity. Of interest, hydrops fetalis is a severe, life-threatening condition with profound edema in the fetus and newborn.
Acute corneal hydrops is relatively uncommon, occurring in 2.6% to 2.8% of patients.1 The incidence of hydrops is higher in other corneal ectatic disorders such as pellucid marginal degeneration and keratoglobus compared to keratoconus. The incidence in these conditions can be as high as 11%.2,3 Males are more commonly affected than females, with age 25 being the average age of onset.4 Eye rubbing and seasonal allergies is associated with the development of corneal hydrops.2,4
Significant, focal, corneal edema is due to a compromise of the barrier function of Descemet’s membrane with a split in Descemet’s layer and the endothelium, allowing aqueous to enter the corneal stroma.5 Corneal hydrops usually resolves spontaneously over 3 to 4 months, with the result being a corneal scar.5
The signs and symptoms of acute corneal hydrops include severe corneal edema with an associated reduction in visual acuity. Epiphora, photophobia, ocular injection and pain may be present. There are multiple management options including hypertonic saline, topical steroids, cycloplegia and a bandage contact lens. Injection of anterior chamber air or gas with compression corneal sutures may hasten recovery.6 Penetrating keratoplasty may be indicated if significant scarring is present.
A recent study investigated scleral lens fitting in patients with keratoconus with resolved hydrops.7 A retrospective case series of patients with keratoconus who developed acute hydrops between January 1, 2015 and June 30, 2018 was performed. Fourteen patients (16 eyes) were included in the study. Prior to hydrops, the median maximum keratometry value of affected eyes was 81.3 D (range 66.3-108.3 D). The median age was 31 years (range 19-52 years). Specialty contact lens fitting after hydrops was not needed for 2 patients (2 eyes; 12.5%) due to good vision in the fellow eye.
The remainder of the patients, 11 eyes (68.8%), were successfully fit with scleral lenses ranging in diameter from 16.5mm to 17.5mm. A median visual acuity of 0.7 (0.5-0.9; decimal Snellen, better than 20/32 Snellen fraction) was obtained. A comfortable wearing time of at least 10 hours per day was reported. Three patients (3 eyes; 18.8%) had limited visual acuity with scleral lenses (n=2) or persistent edema (n=1) and subsequently underwent corneal transplantation. Of the 13 eyes which underwent a scleral lens fitting, 11 eyes obtained satisfactory visual acuity, resulting in a success rate of scleral lens fitting of 84.6%.7 In 5 patients who were wearing corneal RGP or hybrid lenses prior to hydrops, a comfortable refit was not able to be obtained with this lens modality and these eyes were refit with scleral lenses.
This study illustrates the high success rate of scleral lenses after corneal hydrops to provide visual rehabilitation. Scleral lenses provide an easy, fully reversible alternative to classic surgical procedures. The authors recommend a scleral lens fitting prior to corneal transplantation.
Images of acute corneal hydrops in advanced keratoconus.
Fan Gaskin JC, Patel DV, McGhee CN. Acute corneal hydrops in keratoconus: new perspectives. Am J Ophthalmol. 2014;157:921-928.
Gaskin JC, Patel DV, McGhee CN. Acute corneal hydrops in keratoconus: new perspectives. Am J Ophthalmol. 2014;157:921-928.
Grewal S, Laibson P, Cohen E, et al. Acute hydrops in the corneal ectasias: associated factors and outcomes. Am J Ophthalmol. 2000;129(5):702-3. [PMID 10844084]
Fan Gaskin JC, Good WR, Jordan CA, et al. The Auckland keratoconus study: identifying predictors of acute corneal hydrops in keratoconus. Clin Exp Optom. 2013;96(2):208-13. [PMID 23432147].
Yahia Cherif H, Gueudry J, Afriat M, et al. Efficacy and safety of pre-Descemet's membrane sutures for the management of acute corneal hydrops in keratoconus. Br J Ophthalmol. 2015;99:773-777.
Kreps EO, Claerhout I, Koppen C. The Outcome of Scleral Lens Fitting for Keratoconus With Resolved Corneal Hydrops. Cornea. 2019 Jul;38(7):855-858.
Dr. Barnett is a principal optometrist at the University of California Davis Eye Center in Sacramento, specializing in anterior segment disease and specialty contact lenses. She is the past president of the Scleral Lens Education Society. She is an advisor to and/or has received honoraria or travel expenses from AccuLens, Alcon, Alden Optical, Allergan, Bausch + Lomb, Contamac, CooperVision, EveryDay Contacts, Johnson & Johnson Vision, Ocusoft, Paragon Bioteck, RaayonNova, ScienceBased Health, Shire, SynergEyes, and Visioneering Technologies.