The anterior uveitis is the most frequently encountered form of intraocular inflammation and represents a major cause of visual impairment worldwide. Epidemiological studies from different geographic regions consistently show that anterior uveitis accounts for approximately half to nearly all uveitis cases, underscoring its global clinical relevance. Its high prevalence, combined with the potential for recurrent episodes and long-term complications, makes it a significant public health concern.^(1-3)

One of the most well-established associations in anterior uveitis is with the human leukocyte antigen B27 (HLA-B27). This genetic marker is strongly linked to acute, recurrent, and often severe inflammatory episodes of the anterior segment. International reports indicate that nearly one-fifth to one-third of patients with anterior uveitis test positive for HLA-B27, although the frequency varies according to ethnic background and geographic location. In Caucasian populations, HLA-B27 prevalence ranges from 8% to 10%, while studies involving Mexican populations suggest a lower prevalence, estimated at approximately 4%, reflecting genetic diversity across regions.^(1-3)

HLA-B27-associated anterior uveitis most commonly affects young and middle-aged adults, typically presenting between the second and fourth decades of life. Clinical onset is usually sudden, characterized by unilateral ocular pain, redness, photophobia, and reduced visual acuity. Compared with other etiologies, this subtype tends to demonstrate a more intense inflammatory response and a higher likelihood of recurrence. These characteristics increase the risk of cumulative structural damage to the anterior segment over time.^(4-5)

The complications arising from anterior uveitis are diverse and may significantly compromise visual prognosis. Common sequelae include posterior synechiae, secondary glaucoma, cystoid macular edema, and cataract formation due to membranotomy. In patients with HLA-B27-related uveitis, ocular complications have been described in up to nearly half of affected eyes, with cataract development reported in approximately one-fifth of cases. Such complications are often the result of repeated inflammatory insults, disruption of the blood–aqueous barrier, and prolonged exposure to inflammatory mediators or corticosteroid therapy.^(4-5)

Secondary iatrogenic cataract formation in inflammatory conditions may present with atypical features. Dense inflammatory or fibrinous membranes within the anterior chamber can obstruct the visual axis and interfere with aqueous outflow, leading to complex clinical scenarios. In exceptional cases, these membranes may persist or worsen after Nd:YAG membranotomy laser procedures, due to intense and dense inflammatory membranes, contributing to further lens-related opacification and trabecular meshwork obstruction. The coexistence of HLA-B27-associated systemic disease and severe anterior segment inflammation may predispose patients to such unusual presentations. Recognition of these mechanisms is essential for timely diagnosis and appropriate surgical intervention, aiming to restore visual function and prevent irreversible damage.^(4-5)

A 35-year-old female with a previously diagnosed HLA-B27–positive ankylosing spondylitis presented with acute pain, redness, and marked visual loss in the right eye. There was no history of ocular trauma. Best-corrected visual acuity in the affected eye was limited to hand motion at 50 cm; intraocular pressure of right eye was 25 mmHg and 15 in the left eye. Slit-lamp examination revealed conjunctival hyperemia and a dense central inflammatory membrane obstructing the visual axis. Gonioscopic examination was not possible in the right eye, due to the high density of the inflammatory membrane and the patient's pain. However, in the contralateral eye, a Grade III Shaffer was found, without anatomical alterations. The SUN Grading Scheme for Anterior Chamber Flare was used, where a grade of +4 was found, described as Intense (fibrin/plastic aqueous) (Figure 1).

These findings were consistent with secondary cataract formation associated with inflammatory debris following Nd:YAG laser treatment of membranotomy, with exposure of crystalline fragments in the anterior chamber (Figures 2 and 3).

Prior medical treatment, the patient was using 50 mg prednisone tablets orally every 24 hours, as well as TP drops (tropicamide 8 mg/mL and phenylephrine 5 mg/mL) every 12 hours and prednisone drops every 4 hours in the affected eye.

Given the severity of visual impairment and anatomical findings, the patient underwent phacorefractive surgery with intraocular lens implantation. The procedure was uneventful.

The follow-up was carried out without any complications, using antibiotic drops for 1 week, non-steroidal anti-inflammatory drugs (NSAID) drops for two weeks, and steroid drops in decreasing doses until finally being discharged at 6 months. Ocular inflammation resolved with appropriate postoperative management. Postoperatively, the patient experienced significant visual improvement, achieving a best-corrected visual acuity of 20/25.

Ocular involvement in HLA-B27-associated spondyloarthritis is common, most frequently presenting as acute anterior uveitis. Chronic or recurrent inflammation can disrupt the blood–aqueous barrier, promoting the accumulation of inflammatory cells and crystalline material within the anterior segment.⁽⁶⁾

Secondary cataract formation following Nd:YAG laser treatment due to dense inflammatory membranes is rare, especially in young patients. In this case, AS-OCT played a crucial role in identifying the obstruction of the trabecular meshwork by crystalline material, supporting both diagnosis and surgical planning.^(7-8)

Surgical intervention with phacorefractive extraction and intraocular lens implantation proved to be an effective treatment, resulting in excellent visual recovery. This case highlights the importance of careful postoperative monitoring in patients with systemic inflammatory diseases and emphasizes the role of advanced imaging techniques in complex anterior segment pathology.^(9-11)

Furthermore, there is little evidence of reported cases of cataract following Nd:YAG laser application, due to it being a serious, under-documented complication associated with iatrogenesis. Documenting the possibility of this occurrence is necessary for physicians in training, as well as a reminder to veteran ophthalmologist regarding dense inflammatory membranes in young phakic patients.^(9-11)

In conclusion, inflammatory ocular conditions associated with HLA-B27 may lead to unusual secondary iatrogenesis cataract formation after Nd:YAG laser treatment. Early recognition and appropriate surgical management can result in excellent visual outcomes.